The Home Barista'sGuide to EspressoBy Jim SchulmanWho is this guide for?It isn't for someone sitting amidst the packing crates of their first espresso machine looking for quicktips (the Espresso Mini-FAQmay serve that purpose). However, if you've discovered your love forespresso and realize no quick guide will get you to the perfect shot, you've found the right place. This isan introduction to espresso by an enthusiast for the budding enthusiast. It is not just about techniquesand equipment, but also the reasons behind them.The knowledge and skills for great espresso are out there waiting for you, and thanks to the Internetthey've gotten easier to find. But to an outsider, the discussion on web sites can seem like babble.Espresso equipment and preparation are argued over in minute detail, often with no indication of thetopic's importance. And the taste of espresso is lauded or condemned with hyperbole worthy of a poet orwine critic. But the seeming loons posting this stuff are making some of the best espresso on the planet.Understanding what they're talking about and being able to use their ideas in your own espresso makingis the best way to improve.This guide is long and sometimes opinionated. I don't apologize foreither. It conveys the basic knowledge of the espresso community, aswell as some of its arguments and hot button topics. More importantly,it teaches you the language we're speaking and lets you join in.The guide's main topic is making real espresso and espresso drinks athome. The sad fact is, outside of Italy and the other Latin espressomakingcountries, few people have had real espresso. Most cafés selloverpriced hot milk with coffee flavoring, and the majority of the mass market home espresso machinesare designed to produce the same. For such drinks, espresso quality is irrelevant. There have alwaysbeen a few great cafés outside the espresso countries, and thanks to the growing number ofenthusiasts, their number is growing too. But even large cities are lucky if they have more than one ortwo. So for most of us who insist on good espresso, the only option is to make it ourselves.Unfortunately, good espresso is not easy to make—it takes practice. Mass produced home espressomachines are unequal to the task. A minimal set-up capable of excellent shots will cost around US$500,and those capable of delivering consistency and a degree of ease cost $1000 and up. All I can say is thatthe taste is worth it.There is an added bonus. The world of coffee is fascinating and the people in it are wonderful. Becominggood at making espresso means getting to know and appreciate that world and its people. And that isjust as rewarding as the taste of great coffee.
The guide is divided into this introduction and four content pages. It begins with a short history ofespresso and an overview of the contemporary scene. Next the guide turns to the first three of the "fourMs" of espresso: Miscela (coffee blend), Macinacaffe (grinder) and Macchina (espresso machine).Skills of the barista,Mano, are then covered in considerable detail, including instructions for makingcappuccinos and lattes. Lastly, the guide offers a selected set of links that will get you started on thecoffee Internet.If you're an old hand on the coffee Internet, much in this guide will be familiar. But the list of tips in theshot diagnostic section is more comprehensive than any I've run across, and may contain some that arenew to you. The history section has my take on where espresso is heading and may be good for somelaughs, especially in about five year's time.Finally, a word on the reliability of the information in this guide. The basic facts are accurate to the bestof my knowledge. The information on how machine settings and options or shot making variations affecttaste is based on the consensus of the espresso community, and has worked in my own practice.However, there are always disagreements, and in some cases, the evidence is meager. In other words,this guide will get you started making excellent espresso, but is far from the final word. Once you havebecome confident in your technique and taste, I urge you to try out alternatives and judge for yourself.A Short History ofEspressoThe term café-espress has been used since the 1880s, well before espresso machines existed. It meanscoffee made to order,expressly for the person ordering it. It also means coffee fresh in every sense ofthe word: Made from fresh beans roasted at most two weeks prior to use, Ground just before brewing, Brewed just before drinking.Ideally, all cafés and restaurants would serve even their regularly brewed coffee as espresso in thislarger sense—freshly ground in press pots, neopolitans, vacuum brewers or table top pourovers. Thearoma of good coffee is delicate and dissipates in a matter of minutes after grinding, whether it isbrewed or not.People are in a hurry. For many workers, waiting five minutes for coffee to brew is too long. They werealso in a hurry 100 years ago when inventors started looking for faster ways to brew coffee to order. Itbeing the age of steam, the first attempts used steam rather than water. A steam brewing contraptionat the 1896 World's Fair is said to have made 3000 cups per hour. Unfortunately, steam-brewed coffeetastes awful since coffee generally needs to brew at just below boiling (195-205°F or 90-96°C) to tasteits best. In 1901, the Italian inventor Luigi Bezzera came up with a workable solution. Pavonimanufactured these first espresso machines in 1905.
Café Reggio's PavoniThis machine was also steam powered. However, the steam does not comeinto contact with the coffee. Instead, steam pressure at the top of the boilerforces water at the bottom of the boiler through ground coffee. The coffee isheld in a groupconsisting of a portafilter, a metal filter basket andremovable brass mount, and a brew head into which the portafilter attaches.The piping and group were designed to act as heat radiators, so thetemperature of the pressurized water dropped from 250°F (120°C) in theboiler to the correct brewing temperature at the grouphead. This brewingprinciple is still used in stovetop mochapots. Since the water was pressurized,the coffee could be ground finer than in a regular pourover brewer, reducingthe minimum brewing cycle from about 4 minutes to 30 seconds. Espressomachines and their accompanying coffee grinders became the standardequipment for making coffee in Italy, Southern France, Spain and LatinAmerica. In other parts of the world, it followed Italian immigrants whopopularized it in each country they settled.But technology moves on, and this method is no longer regarded as specifically espresso, althoughmochapots and other steam pressured brewers continue to be marketed under the name. In the 1920sthrough the 1940s, Italian engineers experimented with pumping devices to increase the brewingpressure. The first practical one was developed by Cremonesi in 1938 and manufactured by AchilleGaggia in 1946. It used a hand powered piston. On machines of this type, steam pressure in the boilerforces the water into a cylinder, but then it is pressurized further by a spring-powered piston to about 8to 9 bar (120 to 135 PSI), or 8 to 9 times the pressure that had been developed by the steam machines.The spring that powers the piston is compressed by a lever forced down by the barista (Italian forbarkeep)—the person making the coffee. As with the older generation machines, these lever groups aredesigned to cool the water from boiler to brewing temperature.Now we have modern espresso in the restricted sense of the term—coffee brewed with water at 8 to 9 bar pressure between 90°C to96°C. This technology also explains why modern espresso uses thesame amount in a small one ounce drink as was previously used in2½ ounce demitasse espressos or five ounce regular cups of coffee.The pressurization cylinder could only hold that much water,otherwise the arm strength required to compress the spring wouldhave been prohibitive. Finally, if it's done just right, the addedbrewing pressure creates a nice layer of foam over the coffeecalled crema.Early Gaggia lever machineWhat's this scum on my coffee?!?Legend has it that the first patrons to drink the new potion at Gaggia's coffee bar didn't think it was sonice. They asked, "What's this scum (sciuma - foam) on my coffee?" So in a marketing ploy, Gaggiacalled the new drink "caffè crema" instead of espresso. For about a decade, espresso machines weremade with some groups using the old style one bar steam pressure and others using the new-fanglednine bar spring-lever pressure. But in time, the new style won out and became the true espresso. Theterm "caffè crema" died out, only to be revived for another style of coffee drink by the Swiss in the 80s.
Faema E61The next innovations were commercialized in 1961 by Faema.Instead of a piston situated between the boiler and groundcoffee, they used an electric pump to move cold water through aheat exchanger that traversed the boiler to the grouphead. Theheat exchanger was designed to heat the water to the correctbrewing temperature. Since the group was no longer used tocool the water, it too had to be held at the correct brewingtemperature. Faema used a hot water circulation system to keepthe group hot; other manufacturers used a hot water jacket orkept the group in close thermal contact with the boiler for thesame purpose.The cylinder on lever groups only held an ounce of water, limiting the volume that could be used toprepare an espresso. There are no such limits for an electric pump. So why hasn't espresso gone back tobeing a regular or demitasse cup of coffee, only brewed more quickly using pressure? This is preciselywhat the Swiss do for the drink now called a café crema. However, by the time the newer electric pumpmodels came out, espresso had become its own drink category, and people had developed a taste forthe "little cup." The only change to espresso created by electric pump machines is the introduction of thedouble espresso—double the water and double the coffee for a drink with the identical concentration andtaste.Home lever machines had been designed since the 1960s, but they didn't achieve a mass marketbecause of two severe shortcomings: the groups were too small, so the coffee would overheat after afew shots, and the shortened levers required considerable arm strength. The next big breakthroughcame in the late 1970s. A company called Ulka introduced a small, inexpensive pump that could stillproduce the pressure required by modern espresso. This made affordable and small home pumpespresso machines a practical possibility. Gaggia and Quick Mill brought out the first models and manyother manufacturers soon followed.Today'sEspresso SceneKees van der Westen'sLa Marzocco based SpeedsterWe are currently experiencing a new wave of innovation asthe electronics revolution is catching up with coffeemachines. There are fully automated, push button espressomachines which grind and make a fresh shot or cup in onetouch. They do a better job than poorly trained people, butnot as good as the best trained baristas. Electronics arealso prompting a wave of new manual machine designs thatallow more precision and adjustment of both brewingtemperature and pressure.Will this new wave again redefine what we call an espresso? Perhaps it will, and probably it should.
First, a development on the technical side: A good contemporary espresso has a layer of crema, butmuch of the coffee is still liquid. However, every espresso hound has experienced shots that are almostall foam and stable for long enough to drink as such. Increasing precision in the brewing technology isallowing such all-foam shots to become the standard.There is also a more radical change on the horizon. Espresso brewing has a weakness. While it doeswonders for rather ordinary, low grown, low acid coffees from Brazil and Indonesia, it produces too sourand acrid a taste when used with most of the finest high grown, high acid coffees from Central Americaor Africa. These "grand cru" coffees still have to be brewed in the old-fashioned way, or used in onlysmall amounts for espresso blends. I hope that changes in technique, grinder and machine design willsoon bring the very best coffees to the little cup.Why do I think this will happen?The current espresso-making technique was developed in Italy, where espresso is cheap and regardedas the equivalent of take-out coffee. They have refined it to the point where there is no better way toprepare everyday coffees. But in the rest of the world, the situation is very different. Espresso is sold asa premium drink because it is so much better than the local everyday coffees. This has created a largenumber of espresso enthusiasts whose attitude often bewilders Italians. With the advent of the Internet,these enthusiasts, comprised of both professionals and their amateur customers, have come togetherand are improving on the state of the art. Manufacturers serving this market make more precisemachines; roasters use higher quality coffees in their espresso blends; and baristas push the envelopeof skill, especially since the advent of the Barista World Championships. In this friendly competition tobe the best, people will want to use the most premium coffees they can and demand equipment able tounlock their wonders. Most of the new innovators will probably not be Italian, although it will probablybe Italian manufacturers that make use of the discoveries.But there is also a looming shadow—the number of coffee drinkers is declining. Mass coffee marketeershave misread the coffee market for the last fifty years, and their products have become ever cheaperand more vile. Few people new to coffee would knowlingly choose to drink Folgers or Maxwell House asthey are now. The specialty coffee roasters of the 80s did create a new, younger coffee public, but theynow have been sidetracked into pandering with ever more massive and sweet milk concoctionsmislabeled as espresso. These drinks are gradually moving into Coke and Pepsi's turf, and when thesegiants finally notice and bring the stuff out in cans at fifty cents a pop, even Starbucks is going to getsquashed. Espresso is in danger of becoming just another soft drink flavor.The widening range of equipment and beverages labeled as 'espresso' has prompted specialty coffeeassociations to issue standards for genuine espresso. Here is a link to the Italian and thebest American standard. These standards are excellent, but nevertheless, I have some problems withthem: Being voluntary, they do nothing to curtail the misuse of the term 'espresso' by the worst elements of theindustry, Having been adopted by the best baristas for competition, the best cafés for their practice, and the bestmanufacturers for equipment design, they may inhibit the cream of the industry from innovating,
Having been negotiated by large industry players, these standards do not specify freshly roasted, freshly groundcoffee, and thereby get the details right while missing the main point: fresh coffee. Coffee freshly roasted, ground,and prepared is the one thing that cannot be canned and mass marketed. It should be the first linein every espresso specification.If you are reading this, it's likely you are an actual or budding espresso enthusiast. The latestinnovations have been driven and even developed by amateur and professional enthusiasts. It is alsoenthusiasts who can put a brake to the bastardization of coffee and espresso into ever more inane softdrinks. My fervent hope is that this introduction to the art of home espresso will help.Introduction toEspresso BlendsFirst, if you can't tell the difference between a Panamanian and Papua New Guinean coffee, put off theespresso and get to know good coffee first. Buy a freshly roasted half pound each from Central America,Africa, South America, and Indonesia, and learn to appreciate their differences. Those who buy thegreen coffees for espresso, those who roast and blend them, and those who pull the best shots have onething in common: they know their coffee well. In any case, espresso is coffee intensified; if there arecoffees you dislike brewed, you really want to avoid them in espresso.Second, go into a coffee store and look for "espresso roast." What you'll almost always find is darkbrown to black beans shining in oil. Starbucks' success has reinforced the impression that espresso isany coffee roasted very dark. This is wrong on almost all counts. Coffee blends destined for espressocome in a variety of roasts, ranging from a milk chocolate colored dry bean, to a dark chocolate coloredslightly oil-sheened bean, to a black and very oily bean. The very lightest roasts for regular brewing(cinnamon or tan colored) cannot be used for espresso, but otherwise any roast level will work.Instead, espresso is almost always a blend of beans, and the Italian word for this section, miscela,means blend. There is fairly wide latitude in blending, but there are also some general rules. The mostbasic rule of espresso blending is that espresso must have subdued acidity, be heavy bodied, and besweet enough to balance the bitter and acidic flavors in the blend.At the Coffee PlantationA large proportion of the blend will consist of "natural" or "pulpednatural"processed beans from Brasil, Indonesia, Ethiopia, orYemen. Natural or "dry processed" means the coffee cherry is airdried on the tree or on terraces prior to removing the skin andfruit from the pit (the actual coffee bean). Pulped-natural or"semi-wet processed" means the skin is removed, but the fruitremains on the bean while it is drying. These techniques createthe more heavy bodied, sweet, and subdued acidity coffeesrequired by espresso brewing. Such coffees also develop more crema. Single origin, unblended espressois almost always derived from a bean of this type. The drawback of these techniques, even whencarefully done, is they create a few fermented beans with off-flavors that slightly muddy the aroma andtaste.
The alternative, known as wet processing, washes the skin and fruit off the bean prior to drying. Thisprocess produces less sweet, more acidic coffees, which generally would be unsuitable for espresso ifused pure. However, since these beans often have beautifully clean and powerful floral and fruityaromas and tastes, they are used in smaller proportions in more expensive blends to enhance the moresubdued taste of dry processed beans. When these beans are used, the coffee is usually roasted at thelighter end of the espresso spectrum, since dark roasting destroys their aromatics.Finally, some espresso blends use Robusta coffees, which derive from a different species of coffee treefound at lower altitudes and having higher yields. These coffees are generally less expensive than theArabicas discussed above. Low grade Robustas can add body, sweetness, and above all, very strongcrema to an espresso. But they do so at the expense of having an unpleasant, burnt rubber smell. Highgrade Robustas do not have this offensive odor, but will usually muffle the other aromatics. Their use iscontroversial. Many very gifted espresso professionals use Robustas, while many others would nevertouch them.At the RoasterDifferent roasters have different blending strategies. Some use only two to four different coffees; theseblends can have very distinct tastes and will vary a lot year to year. Other roasters will try to keep theblend's taste the same year in, year out. They will do this by using seven to twelve different coffees,many from different plantations in the same country and region, so as to average out the annualvariations of coffees from any one plantation.As with all coffee, espresso blends are always best when used within two weeks of roasting. Unlikeregular brewing, the carbon dioxide in the beans in the first day or two after roasting can sometimesinterfere with the espresso extraction, so many cafés allow the coffee to rest 48 hours prior to use.My main advice is to first find several good local roasters. Try many different espresso blends, varying inroast levels, use of Robusta (or not), level of acidity, or use of wet processed coffees, and then decidefor yourself which styles you like most. Ask the roasters about what's in the blend; the exact recipes areusually proprietary, but they will be happy to give you general information so you can develop aninformed preference. If you home roast, try various dry or semi-wet processed Brasils, Indonesians,Ethiopian and Yemen coffees, and create a blending base from your favorites among these. Then addsmall amounts of your favorite wet processed, high grown Arabica to give it some distinctiveness. If thislater coffee is exceptionally sweet and low acid, more than the usual 10% to 20% can be used.Single Origin EspressoAs mentioned earlier, most washed, high grown coffees are unsuitable for espresso either straight or inhigh proportions in a blend. In my opinion, this shows that espresso technology requires furtherdevelopment. It would be absurd if you tried to buy a coffee and were told it was too strong to beprepared in a presspot.However, espresso technology has advanced far enough so that some high-grown, washed coffees canmake interesting and sometimes spectacular shots. These usually don't have the balance of conventional
lends, but can have far more interesting aromas and tastes. Low toned, sweet coffees, even those fromregions usually not regarded as suitable for espresso, are always worth trying as single origin shots. Theresearch that could adapt espresso equipment to the full range of coffees won't happen until morepeople try these, develop an appreciation for them, and form a market for roasters, cafés, andmanufacturers pushing the envelope.Water for EspressoFinally, a note about water, the other constituent of good coffee and espresso. Water for coffee shouldbe pure and odor free. Charcoal filtering to remove chlorine and sediments from municipal water is agood idea. Further filtering is required if the water is from a well having iron, sulfur, heavy metals, ororganic contaminants. Alternatively, consider bottled water.Note that "pure water" in this case does not mean distilled or free of all minerals. Natural water containscalcium carbonate and some magnesium carbonate; these constitute the water's hardness. Overly soft(low mineral) water will create a light bodied, metallic and excessively bright tasting shot. Overly hard(high mineral) water will scale the machine, while the chalkiness of the calcium carbonates precipitatingas the water heats will interfere with proper extraction. The best coffee water has about 5 grains (90mg/L) hardness and 150 mg/L total mineral content. For espresso machines, water at about 3 grains (50mg/L) and 90 mg/L total mineral content is used to reduce descaling costs. This is a compromise on theideal water for espresso, but the 90 mg/L shots are almost indistinguishable from shots with the higher150 mg/L mineral content. If your tap water is excessively hard or soft, look into bottled water or watertreatment options, many of which are not expensive.Introduction toEspresso GrindersThere is only one thing every espresso expert agrees on: The grinder is the single most important pieceof coffee equipment you'll buy, and the last place you'd want to skimp. This has a simple reason—thecoffee grind is both the most critical and the weakest link in espresso making. It is critical, since unlikeregular brewing, the grinder adjustment determines both the espresso's extraction rate and it's brewingtime. The grinder is the weakest link because ground coffee is anything but uniform.Grinder AdjustabilityWhen brewing, there's two time factors—the amount of time the coffee should brew, and the amount oftime it does brew. The grind fineness determines how long it should brew—the finer the grind, the fasterthe proper brew time. Less brew time is better when the grind is finer because more surface area is incontact with the water and the coffee solubles dissolve more quickly. But for most brewing methods, theamount of time it does brew is determined by you since you can choose to pour through the filter fasteror slower, let the French press brew longer or shorter, etc. This means for non-espresso preparation,you can stick to one grind and pick a brewing time to match.In espresso, the grind fineness also determines the brewing time, but does so in the opposite directionfrom the time it should brew. The finer the grind, the more the coffee puck resists the flow, and thelonger it takes to brew the same amount of espresso. But the finer the grind, the quicker the coffee
solubles extract. In other words, there is only one correct grind setting that gets just the correct timing,and even small deviations screws it up, giving you either an over or underextracted espresso. Inpractice, good baristas will frequently make minute adjustments to the grind to keep it at the sweet spotas beans age, and ambient conditions change.Experience shows that the correct timing for espresso is brewing one ounce singles or two ouncedoubles in about 25 to 30 seconds; grind fineness should be selected to produce this volume in thistime. There are a few things the barista can do to compensate for a slightly off grind, which I'll discusslater in the Mano section. But these tricks are limited; in practice one needs a grinder with lots ofavailable settings.Many home grinders only have 10 to 20 settings over the entire range from fine to coarse. Thistranslates to about 2 to 4 settings in the espresso range, which is not enough to get the grind right. Anespresso grinder either needs a stepless adjustment, or at least 40 settings over the entire range inorder to work well.Grind QualityIn theory, if all the ground coffee had the sameparticle size, it would all brew at the same rateand you could get a perfect extraction. If thegrind size is not uniform, the smaller particlesoverextract, the larger ones underextract, andthe result is less than perfect. Unfortunately,coffee is brittle and shatters as it is ground. Soeven the best contemporary grinders produce awide distribution of particle sizes. Moreover,some size variation is required for the mechanics of the espresso puck. If all the particles had the samesize, there would be large gaps in the coffee puck, and the pressurized water would gush through. Awide distribution of sizes creates a dense pack that resists the flow and allows proper extraction. This isprobably the reason why high grown coffees don't do well as espresso since their fines (smallest, dustlike grind particles) create a very acrid taste.The very best grinders are commercial conical burr grinders. These produce elongated particles whichpack well, and fewer fines. They are currently very expensive and beyond the reach of almost all homeespresso enthusiasts.Commercial flat burr grinders are nearly as good, although they produce slightly more fines and a moremetallic taste with high grown coffees. However, smaller models are only one-third to one-quarter theprice of commercial conical burr grinders, and they include some packaged specifically for home use.These run from about $250 to $500 and are recommended for anybody serious about espresso.
Mazzer flat burrs - note sharp deep ridgesFake flat burrs - knobs crushbeansThere are several manufacturers of home conical grinders. These models work very well for brewedcoffee, and some models have enough grind settings to work fairly well for espresso. However, the tastewon't be as good as a commercial grinder's. They have lower power motors, plastic gears and lighterduty burr mounts; so the burrs wobble and vary in speed slightly during the grind. Espresso particle sizeis measured in the 1/1000ths of inches, so even a little wobble and speed change degrades grindquality. Nonetheless, such grinders are a decent economy choice and cost around $150.Solis conical burrs mounted on softplasticInnova conical burrs mounted onhard resinFinally there are contraptions falsely called burr grinders that cost around $50. These are not actuallyburr grinders, but use knobs to crush the beans. Since this produces a large quantity of fines, they willproduce an acrid shot with even the most mild mannered all-Brasil blends. They are to be strictlyavoided for any coffee use. Whirling blade grinders (that look like tiny blenders or food processors) arealso to be avoided, since they too produce excessive dust.
There are non-coffee factors to grinder design that affect their cost. In general, grinders which do agood job but are less expensive tend to be slower, noisier, and messier. It is up to each person to weightheir priorities in economy versus lack of annoyances.It seems fairly clear to me that any fundamental innovation in espresso will require improvements ingrinding coffee. However, the problems are great, so this is an area where technology moves slowly. Inthe mean time, the existing technological deficiencies in grinder design means that one has to buy thebest grinder possible to get decent performance.Introduction toEspresso MachinesIn principle, an espresso machine is a simple device; it is designed to heat water to between 90°C and96°C, and then push it through a puck of ground coffee at a pressure of 8 to 10 bar. The way aparticular machine handles heating the water and creating the requisite pressure defines its type.Pressure MethodsSpring Levers: This is the oldest system, introduced in the 1940s. A cylinder and piston system is usedto pressurize the water. In many home machines of this type, the pressure is applied directly by theoperator. The drawback of this is that it is very difficult to smoothly and exactly apply the required 40 to50 pounds of force on the lever. All commercial lever machines and more sophisticated home machinesuse an uncoiling spring to power the piston. The operator compresses the spring, which does not requirethe force to be applied precisely. The reason a single espresso uses about an ounce of liquid is that thiswas the practical maximum amount of water that could be manually pressurized by this method.In general, spring lever machines cannot be adjusted to deliver a precise pressure. They start at around9 bar and, as the spring uncoils, smoothly diminish to around 7 bar by the end of the shot. This does notseem to adversely affect shot quality, and can in some case reduce bitterness.This system applies pressure very smoothly, without the vibrations introduced by the rotary orreciprocating action of motor pumps. This difference may affect shot quality in two ways. First, it slightlyreduces the amount of crema compared to motorized shots, although one very occasionally getswonderfully creamy shots. Second, the taste of the shot is purer and more transparent, with lessbitterness and acridity than otherwise identical shots from motor pump machines. How much of thiseffect is due to the other properties of lever machines, and how much is due to the lack of vibrations isunknown. But the actual difference in taste is quite apparent.Rotary Pumps: The great majority of commercial espresso machines use rotary pumps, which cangenerate enough flow at 9 bar to serve multiple groups simultaneously. They are easily and preciselyadjustable for pressure, and the pressure does not vary with the flow rates found in these machines.While they are not vibration free, they are smoother and quieter than the smaller vibratory pumps foundon home machines. So, although they are a vast overkill for home use, some espresso enthusiasts getrotary pump espresso machines for their better adjustability and reputedly cleaner taste.
Vibratory Pumps: The home espresso market has exploded because of the vibratory pump, a cheapand small device that can pump just enough water at 9 bar to make a double espresso. Since thesework on a reciprocating principle, they introduce far more vibration than rotary pumps. Much of this canbe damped out by good overpressure valves and flexible piping, and better home machines have these.But still, they may produce a slightly less transparent taste than the other kinds. On the upside, thevibrations may create slightly more crema.I am qualifying statements about the taste differences between vibratory and rotary pump espresso.When vibe pumps are properly adjusted, the reputed differences are contested, and in any case subtle.Also they may be influenced not just by differences in vibration, but also the different speeds at whicheach type reaches full pressure at the start of the shot.Unlike rotary pumps, vibratory pumps produce a pressure that is strongly inverse to the rate of flow. Ifthere are no controls, one must make a 2 ounce in 20 to 25 seconds espresso to get the pressure insidethe 8 to 10 bar range. Smaller, slower pouring shots will have far higher pressures; larger, fasterpouring shots will have far lower pressures. Better home machines have overpressure valves to limit themaximum pressure to about 10 bar, so that single and ristretto (reduced) espressos can be madewithout exceeding the normal extraction pressure range. Long shots, like Swiss café crema, will brew at4 to 6 bar, no matter how well the vibe pump is controlled.Heating MethodsBoiler/Heat Shedding Group: This is the oldest system. Wateris taken directly from the steam boiler at a temperature ofroughly 120°C (250°F). The water's temperature drops to brewrange in the group prior to its reaching the coffee. Most springlever machines work in this way. Obviously, this is not a veryprecise way to regulate temperature. If the group is too cool, thefinal brew temperature will be too low; if it overheats, the finalbrew temperature will be too high. On commercial levermachines, shots have to be made at just the right pace to keepthe group at the correct temperature; on many home levermachines, the machine has to be turned off after four or fiveshots and left to cool.Heat Exchanger: Most commercial and larger home machines use this system. The heat exchanger isbasically a pipe inside the boiler. As the water is pumped to the group, it goes through the pipe andheats up to brew temperature range. The average temperature can be adjusted by lowering or raisingthe steam boiler's temperature and pressure. Since the water arriving at the group is designed to be atthe correct temperature, the group itself also has to be heated to the correct temperature so as not tochange that of the brew water. This is done either by circulating hot water through the group or bybolting the group directly to the boiler. Again, this is not a very precise system, and it is difficult toadjust the temperature to a precise level. However, good engineering can make heat exchanger systemsvery stable, so that they hold the same temperature within 1°C to 2°C. This is mainly done by usingvery massive groups and heat exchangers. Once these are at the correct temperature, changes in therelatively small amounts of water going through them do not affect their thermal stability. However,they still depend on shots being made a steady pace. After a long idle time, the water in the heat
exchanger will overheat, and the group may also drift to the wrong temperature. One has to go througha regime of flushing water through the group to get the system to the right starting temperature formaking shots. The exact details of this regime vary from machine to machine, however the article How IStopped Worrying and Learned to Love HXs offers general advice that can be adapted to most heatexchangers.Heat exchanger systems have an important advantage compared to smaller single boiler homemachines. They can steam milk and make shots at the same time, whereas single boiler machinescannot.Single Boiler: Smaller home machines have a single boiler without a heat exchanger. When makingespresso, one thermostat is used to heat the water to 90°C to 96°C; when steaming, anotherthermostat is used to heat the water to 125°C. There can be up to a one-minute wait for the boiler toswitch from one temperature to the other. The major quality factor in these machines is the size of theboiler. The poorest machines have a thermoblock that heats less than an ounce of water on the fly. Thebest machines have boilers up to 25 fluid ounces. Although bigger is always better in terms of thermalstability, above about 12 to 16 ounces of boiler size, the added stability becomes somewhat academiccompared to other factors.In most home machines, the thermostat is a simple bi-metallic disc mounted to the outside surface ofthe boiler. These have a deadband (the range between turning on and off) of around 10°C. In order toget consistent temperatures shot-to-shot, you begin brewing espresso at the same point in the range,typically the moment it reaches maximum temperature. Varying the shot temperature is very difficult,and requires timing out the thermostat cycle precisely—a technique called temperature surfing.Better home machines use vapor pressure or electronic thermostats which measure the water directlyand have narrow deadbands. Although these are adjustable in theory, in practice, they are not veryaccessible.Many home espresso enthusiasts take one of the better single boiler home machines and use industrialtemperature controllers (called PID controllers) to precisely regulate the temperature. When this is done,these machines deliver very repeatable and adjustable shot temperatures.Double Boiler: Single boiler machines cannot steam and pull shots at the same time. However, with theright controls, they deliver very precise temperature control. Commercial manufacturers took note ofthis and are producing double boiler machines. These have one boiler used for brewing and another forsteaming, with each boiler set to the correct temperature for its function. In theory, such machines candeliver completely stable temperatures. In practice, groups are not regulated and shot temperatures canvary as widely as on the better heat exchanger models. Nevertheless, since these espresso machinesalmost always have accessible electronic controls, they are much easier to set to the desiredtemperature than any other kind of machine. Also, this is an active area of innovation, and double boilerespresso machines are becoming more precise with each new model iteration. The most advancedcurrent models claim to keep temperatures within 0.5°C of the setting under all operating conditions.There are several models of double boiler machine now available for the high end home market.How Important Is Precision?
It depends. Most home espresso enthusiasts buy small commercial machines, or do their own upgradeson better home models, not because they drink more coffee, but because they are looking forconsistency. Consistency in pressure and temperature has three aspects:Repeatability from shot to shot so that the temperatures and pressures are the same for every espresso. Thisis essential, since if the machine's pressure and temperature change from shot to shot, you can never get aconsistent taste in your espresso. It's work to get repeatable shots on even good stock home machines.Commercial models and DIY upgrades make this a lot easier.Stability within the shot so that the temperature and pressure hold the same value throughout. A machine willspoil the espresso if the temperature or pressure vary widely. But if they vary a small amount and in a consistentmanner, there is no evidence that espresso quality is compromised. For example, spring lever machines deliverthe same pressure curve, one that drops towards the end, whereas motor pumps deliver even pressurethroughout. HX machines usually have "humped" temperature profiles varying a few degrees Fahrenheit within ashot, whereas single and double boiler machines have straight line temperatures, also varying a few degrees atmost. Repeated tests have shown no clear advantage for any of these behaviors. It should be noted that verysmall pump machines that cost in the $100 to $200 range usually are unstable, and temperatures and pressureswill vary widely and unacceptably within a shot.Adjustability so that one can change the brew temperature or extraction pressure. This is essential if you want touse a particular style of blend or coffee on the machine, since differing blends and roasts favor different pressuresand temperatures. If the machine is not easily set, one has to find a blend and roast style that is suitable for it,and stick to it for the best espresso. Lever machines are not easily reset. HX machines and mechanically controlledmotor pumps require opening the machine up for an adjustment, while electronically controlled dual boilermachines, or PIDed home machines can have their temperature and (sometimes) their extraction pressureadjusted on the fly.Machine Factors Not Related to Coffee QualityYou will pay more for beautifully designed cases, for higher quality, long life components, and for goodworkmanship and maintainability. Inexpensive home machines have almost become disposable, andsuch features are likely a waste of money. More expensive machines are like major appliances—theirlifetime is measured in decades, and they are designed to be repaired and serviced. Since it is moreconvenient to do routine maintenance and service yourself, a well designed machine with high qualitycomponents greatly increases the joy of ownership. Since such machines are long term fixtures in thehome, the quality and type of case design should be chosen with their location in mind. It is rather oddto walk into a beautiful marble tiled kitchen and see its granite counters populated by cheap plasticgadgets; on the other hand, a machine destined for placement behind a counter or in a working kitchencan be simple and utilitarian in design.Introduction toBarista TechniquesBarista technique breaks down into three time scales and skill levels:The first is the minute or so spent grinding and making the shot. Thekey here is acquiring the skills to make shots consistently. One shouldbe able to turn out four or five in a row with virtually the same timing,volume, color, crema and taste. This skill is a physical thing, that is,it's a matter of training and practice rather than learning.The second is the time spent carefully tasting an espresso or series ofespressos, identifying the flavor balance and defects, and making
adjustments to ones pull or machines to correct them. The "dialing-in" process for a new blend usuallyrequires a series of shots to get a satisfactory result, and can proceed over several days to fine tune it.To do this well, one needs to have experience in tasting and analyzing good espresso. One also needs toknow how changes in extraction variables and machine settings affect the espresso's taste.The third is acquiring experience and informed preferences with a wide range of coffees, blends,espresso equipment, and alternative techniques. If you or someone you're serving wants an espressowith a specific pallette of flavors; you will know how to provide it. Home roasting and blending helps inthis. So does visiting good cafés and roasteries, and talking with the knowledgeable people there.Most people in North American drink their espresso in a latte or cappuccino. Until about ten years ago,there wasn't much to preparing these. But in recent years, the techniques of microfoaming and pouringlatte art have become widespread, vastly improving the quality of these beverages. Latte art should be apart of every home barista's repertoire; an introduction to its technique is given later in the guide.Pulling Shots by the NumbersThe actions for pulling a shot of espresso are:1. Choosing singles or doubles.2. Correctly setting the grinder.3. Readying an idle machine for shot making.4. Grind, dose, level, and tamp.5. Working the shot.6. Post-shot tasks.Singles or Doubles?Espresso comes in two sizes: single and double. A single is a 0.6 to 1 ounce espresso made from 6 to 10grams of coffee; a double is a 1.2 to 2 ounce espresso made from 12 to 20 grams of coffee. Singles anddoubles take the same amount of time to pull, roughly 25 to 33 seconds, and the coffee flavors andaroma should be the same.However, I recommend that you start by making doubles. While the flavor of singles and doubles is thesame, the crema on singles will always be less than on doubles. The mechanism underlying this isexplained in the diagnostics section. Good crema improves mouthfeel and ameliorates harsh flavors, sodoubles are more forgiving than singles. Good singles require perfect technique and very long practice;producing good doubles is easier.Grinder adjustmentWhen first using a new grinder or when changing coffee blend, the grinder needs a large adjustment tobe set correctly. On a new grinder, grind briefly and pinch the grind between your fingers; if it's in thecorrect range, it should feel very slightly granular, just short of a powder. Many grinders display a rangeor setting for espresso; if yours does, start there. When changing blend, just start with the currentsetting.
At this point, grind, dose, tamp and pull double shots as you usually do (see below if this is your firsttime), then correct the grind setting—finer grind for less volume or longer pour times, and coarser grindfor shorter pour times or larger volumes. Here's what you are looking for initially:Time the shot, and run it into a cup from which you can tell the volume. Stop the shot when the flowlightens to "blonde," a tan color showing some transparency. This flow color indicates that the properamount of coffee has extracted, about 20% of the puck. Try to get into the middle of the acceptablerange: 1.5 to 1.75 ounces in 25 to 30 seconds. If the shot takes longer, or delivers less volume, grindcoarser; if it delivers more volume or happens in less time, grind finer. More precise adjustment requirestasting shots and diagnosing them. This is explained in the next section.If on a stepped grinder, no grind setting gets you within this range, start grinding on the setting thatwas closest but too fine, and halfway through, switch to the setting that was closest but too coarse.Then consider buying a better grinder.Readying an Idle MachineAlmost all running but idle machines will have some component at the wrong temperature, so that ashot pulled from them without further ado will taste wrong. A machine that is turned off and cold willneed to be turned on and left to sit for fifteen minutes to an hour to get it up to temperature, dependingon the machine's size. At that point, it will have the same characteristics as an idle machine, and willalso need to be prepared for its first shot.A boiler/heat shedding group machine like most spring levers may need a "blank shot" to warm itslightly. Running one dose of hot water through the group will do.Heat exchangers are designed to heat the water to the correct espresso temperature as it flows throughthem. Typically they are adjusted to do this at a normal shot making pace, that is, one espresso everyminute to two. If the water sits in them longer, it overheats and has to be flushed out.If the group has a tendency to get cold, a blank shot of the right amount (typically 1 to 2 ounces) willcool the heat exchanger and heat the group to the correct shot making level. If the group has atendency to run hot, a larger amount needs to be flushed so that the fast flowing water cools both theheat exchanger and the group. In this case the required amount is typically 4 to 8 ounces. The correctprocedure varies by machine model.In brew boilers controlled by mechanical thermostats, the water can be well below the thermostat'sturn-off temperature. On these (typically home machines), water should be run until the heater turnson. On some machines, you should time the heating cycle and pull the shot after the heating elementhas run the same amount of time in each case. On others, one should wait for the heat to turn off, andpull the shot immediately.In brew boilers controlled by electronic thermostats, the boiler water will be at the correct temperature.In some cases, however, the group will be at the wrong temperature, usually cold. In this instance,
simple flushing doesn't work well, since one can overdraw the brew boiler and cool it off. One procedure,devised by David Schomer of Café Vivace, is to leave the spent puck from the previous shot in thegroup. Flushing through it will slow the flow sufficiently to warm the group without overdrawing on thebrew boiler.It pays to speak to other owners of your model of espresso machine to get the exact procedures thatmachine requires (or if your machine was reviewed on Home-Barista.com, read the Pulling Shots by theNumbers section of its buyer's guide). Alternatively, you can mount a thermocouple in a brew basket oron the showerscreen, measure the water temperature, and devise your own procedures. I wouldrecommend purchasing a thermocouple and reader for this purpose. They are quite inexpensive— asmall fraction of the machines cost —and will certainly help to get the most out of it.Barista Technique:Dose, Distribute, Tamp. Repeat.These are the actions required to fill the portafilter with coffee and getit ready for pulling the shot.Setting the grinder has been discussed previously, now let's look moreclosely at the actual grinding. Many grinders have storage for theground coffee and provisions for dosing it. This defeats the purpose ofespresso, which by definition is about doing everything fresh. So firstget rid of any old grinds, then grind just enough for the shot. Onespresso grinders with dosing chambers, this requires flicking thedosing lever repeatedly until the chamber is quite empty. It also meansclearing out the exit chute from the grind chamber, which will otherwiseclog with stale grounds, using a small brush, chopstick, or similar small non-metal implement (neveryour fingers!).The nominal doses for espresso are 6 to 7 grams for a single and 12 to 14 grams for a double. Recently,many cafés have raised dose sizes to 8 to 10 grams for a single and 16 to 20 grams for a double.Whatever the dose, consistency is the key. Weighing the grinds is accurate but time consuming, sousing the same volume each time is the most popular choice for dosing. The most common method is togrind for a preset time (a photo lab developing timer is a good add-on for this), filling the basket looselywith grinds, then leveling it off and discarding the excess grinds. Some baristas prefer a slightlyoverloaded basket. In this case, the most repeatable method is to tap the basket and portafilter a fewtimes to slightly compact the grinds prior to leveling them off. This will add about 20% to 25% to thedose. Finally, some home baristas prefer to dose by measuring the volume of the amount of beans theyput into the grinder. As a rule of thumb, a leveled coffee basket full of beans delivers the same amountof coffee as the overloaded basket technique. Which technique you use is less important than stickingwith it and learning to be consistent. It's a good idea to weigh the coffee after dosing for a few days untilyou become fairly consistent (within 0.5 grams of the desired weight).
To create a sound puck, leveling the ground coffee is vital. Prior to tamping one wants the ground coffeedistributed as follows:Its depth even all around the basket.Its density even all around the basket.No gaps or breaks, especially around the perimeter of the basket.The most common method to get this is to combine leveling with sweeping excess coffee from thebasket. Prior to sweeping the grounds away, use your finger to move the grounds gently around thebasket to fill in all gaps. An alternative, for those with larger palms accustomed to heat, is to presslightly on the grounds with the thumb part of the palm, and rotate both it and the portafilter todistribute them evenly. This technique is known as the Stockfleths Move (video). If you have a tamperslightly smaller than the basket, the Staub tamp, a rotating motion by it, or very lightly tamping in thefour compass directions, prior to heavy tamping will also work. Finally, you can lightly level the groundsseveral times while filling the basket using the small tamper attached to the grinder.Tamping means taking a cylindrical press that fits snugly into the basket and compacting the groundsprior to the shot. The object is to seal the puck so that the brew water moves through it evenly withoutfinding weak spots. Channeling occurs when the pressurized water gushes through the weak spot whilenot flowing anywhere else, thereby spoiling the shot.The classic tamp is a straight down press at 30lbs pressure, followed by a light twist to settle any straygrinds. In Italy, it has become the custom of most cafés to grind slightly finer and use a very light tamp(about 10 pounds) using the tamper mounted on the coffee grinder. Stronger baristas may use heaviertamps, while some use a nutating motion (rolling the tamper in a motion like a flipped coin settling) toaccentuate the pressure towards the edges of the basket. An alternative to the nutating motion is usinga convexly curved tamper, which accomplishes the same thing.If all these alternative ways of leveling and tamping leave you bewildered, take some comfort inknowing that most experts are just as confused, and that there's help. A recent innovation known asthe naked portafilter (shown above) allows you to see directly how well the extraction progresses. Thenaked portafilter is not the latest wrinkle in pornography, rather it is a portafilter in which the bottomhas been sawed off. So, instead of being directed into a spout, the coffee exiting the sieve at the bottomof the basket drops directly into the cup. If the level and tamp are correct, the espresso will quicklycollect at the center of the basket and descend as a single stream into the cup. If it is incorrect, littlesprouts will squirt off in all directions making a mess. A few days with a naked portafilter will guaranteethat your leveling and tamping techniques, whatever they may be, are working correctly. As a bonus,the stream off a naked portafilter is rather pretty (especially if flash photographed), the crema volume isincreased, and there are no stale coffee oils from the bottom of a conventional portafilter getting intoyour espresso.Barista Technique:Good Extraction, Good EspressoEven very experienced baristas often don't take advantage of the opportunities to improve the espressothat are available while making the shot. They lock the portafilter into group, turn on the pump or pullthe lever, and pray. If the shot is roughly right, they'll serve it and make small grinder adjustments for
the next one—if it's way off, they'll dump it and make larger grinder adjustments. This approachrequires that grind settings and machine temperatures and pressures be very close to perfect. However,if you know a few things about how espresso extracts, you can correct somewhat larger deviations fromthe correct levels of these variables on the fly. Moreover, however correct or incorrect the variables, youcan assure that you're getting the best espresso possible under the circumstances.Ending the Extraction by ColorThe first aspect of working the shot is to make sure the extraction is correct by ending the shot at thesame color every time. The exact color depends on blend and machine, but it is always a light tandescribed by experienced baristas as blonde. If the stream is still well filled with crema, it is not yetblonde. If the stream entering the cup discolors the crema into a light tan color, it's gotten lighter thanblonde. Typically the right point is around the time when the stream starts changing from foam to liquid.How and why does this work? Underextracted coffee is sour and thin; overextracted coffee is weak, withbitter and acrid notes. As the ground coffee extracts, the water flowing through it colors less and less.So the color is a measure of the degree of extraction and stopping at the same color means stopping atthe same level of extraction. Perfect extraction occurs when 20% of the ground coffee's weight hasdissolved into the coffee. Knowing the color that corresponds to this so you can stop the extractionmeans getting the best espresso for a given pull every time.The graphic below illustrates the 'extraction space' of espresso, showing shot time and volume, thechanges in color, and the effect of grind fineness. It will be used extensively in the diagnostic section,but will also help clarify the concepts discussed here.Let's suppose the grind is way off and you don't know about this.
Based on what you've read, you are looking for a two ounce double espresso in 27 seconds. If the grindis too coarse, you get the two ounces in about 15 seconds. If you stop there, the cup will tasteunderextracted. If you go for 27 seconds, you'll get an overflow of overextracted bilge. But if you stopthe shot at the right color, you'll have a 20 second, 3 ounce lungo (long shot)—not what you wanted,but quite drinkable. Now suppose your grind is way too fine. If you don't know the rule, you'll have a ½ounce of intensely sour stuff at 27 seconds, or 2 ounces of intensely bitter stuff after a minute. If you doknow the rule, you'll have a 1 ounce ristretto (short shot) after 35 seconds—again, not what youwanted, but enjoyable nevertheless. After you tried the shot, you can correct the grind, or even staywith the "mistake" if you decide you liked it more. In any case, you'll have a range of shot possibilitiesyou can explore.As can be seen on the extraction chart, it takes a longer time for the flow to go blond on a restrictedvolume shot than on a long volume shot. This relation between shot blonding and the volume and lengthof extraction is known among espresso enthusiasts as Al's Rule, named after Al Critzer of Cimballi.Taking Advantage of the 'Rule of Thirds'Sometimes it is not the grind, but the temperature, pressure, or even the blend itself that are off.Ideally, you would fix this by correcting the problem directly (see next section), but in many cases ittakes more time that you have before rushing off to work, running errands, and so on. Another aspect ofthe extraction allows for a quicker fix. The early part of the extraction contains a predominance of theacids and the portion derived from fines. The central part of the extraction contains a predominance ofthe sugars and caramels. The final part of the extraction tends towards bitterness, but will also be fairlyweak, sometimes almost tasteless. Among enthusiasts, this is known as the rule of thirds.So, if the espresso is too sour, or worse, has the citrus peel acridity from high grown fines (a brightlingering bitterness mainly on the roof of the mouth), let the first second or two of the flow go into thedrip tray. This is an old Italian barista trick for dealing with rioy Brasils, but it can also be used ongourmet blends containing a lot of acidy high grown coffees.On the other hand, if the espresso tastes flat or bitter-dull, stop the extraction at a darker color toreduce the proportion of weak bitterish coffee, and increase the proportion of the intense flavors fromearly in the shot.If the espresso is not sweet enough, you can do both by capturing the flow after a few seconds andending while the flow is still darker. This "center-cut" shot will favor the sugars and caramels in theextraction.Barista Technique:Better Extraction, Better EspressoThe basic shot making techniques get you decent espresso, but not necessarily the best espresso. Forthat, you want to find which combination of pressure, temperature, grind, and finishing color works bestwith the blend. Also, things do go wrong—temperatures and pressures can drift, burrs get dull, machinescan build up coffee oils faster than usual and require an unscheduled cleaning. Each of these mars the
Heat exchanger machines are set by adjusting thepressurestat, doing a sequence of eight shots or so at yourTemperature measuring portafilternormal rhythm, and seeing where the shot temperature settles. After that, you should also adjust theflush to get an idling machine to that temperature. For one-off experiments or single-shot home use,simply adjust the flush amount (see How I Stopped Worrying and Learned to Love HXs for more details).Machines with electronically controlled brew boilers can be set from the front panel without fuss. Vaporbulb thermostats can be adjusted inside the machine. Both types should be checked with athermocouple thermometer to confirm the actual brew temperatures.Manipulating the Extraction VariablesYou control the extraction by setting the grinder finer or coarser and ending the shot at a certain flowcolor, shot volume, or elapsed time. I recommend using flow color as the way of determining the end ofthe shot, as discussed in the previous section. Each combination of grinder setting and ending colorgives a unique combination of shot time and shot volume (when using the same basket, coffee amount,blend and machine). In fact, fixing any two of the variables (grinder setting, shot color, time, andvolume) fully specifies the other two.Barista Technique:Diagnosis of Extraction ProblemsEspresso is mostly defined in terms of shot time and volume, since these are easiest to measure. Byconvention, the volume specifications for espresso are total volume, combining crema and liquid.The dwell time, the time it takes from turning on the pump to seeing the first drops of espressoemerge from the basket varies from machine to machine. So by convention, espresso extraction timesare specified from the moment the pump is turned on.I will specify the diagnostics in terms of shot ending color and volume, since these have the mostintuitive correspondence to espresso taste. This means you should end the shot at the specified color,and then set the grinder to get the specified volume.TerminologyVolume Terms:Ristretto range: 1 ounce to 1.5 ounce doubles. Compared to normales, the taste will be more intense andsweeter. Ristrettos usually have less crema.Normale range: 1.5 to 2 ounce doubles.Lungo range: 2 ounce to 3 ounce doubles. Compared to normales, the taste will be slightly milder and lesssweet; with certain blends, the crema on a short lungo can be better than for normales.Color Terms:Dark stop: stopping the shot while the flow is still foamy and brown. Compared to a normal stop with the samevolume, the taste will be slightly more intense, and balanced towards acidic.Normal stop: stopping the shot as the flow goes from foamy and brown to more watery and tan. This pointmarks the optimum extraction amount of 20% of the coffee solids.Light stop: stopping the shot sometime after the flow has become watery and tan colored. Compared to a normalstop at the same volume, the taste will be slightly less intense and balanced towards bitter.Special Terms:
Optimum crema range: exact figures are basket dependent, but generally, normal to high flow rates are best.Typically 1.33 ounces dark-stopped to 2.25 ounces normal-stopped has the highest proportion of long lastingcrema. Singles cannot extract at this flow rate, so tend to have less crema.Start dump: initial few seconds of flow out of the portafilter, which is black and without crema, is allowed to gointo the drip tray. The cup is inserted only as the flow gets brown and foamy.Center cut: a start dumped and dark stopped shot.Diagnosing the Taste and Appearance of anExtractionDiagnostics means tasting the espresso and correcting itsdeficiencies by adjusting setup or extraction parameters.In a perfect world, correcting for one deficiency wouldnever interfere with correcting for another. In the realworld, there sometimes are conflicts, and you mustprioritize. The highest priority goes to gross cremadeficiencies, since these indicate that some parameter ofthe shot is well outside proper espresso range. The nextpriority is taste flaws that make a shot undrinkable. Finally, with these eliminated, you can work on finetuningeverything to get the most harmonious taste.Gross Crema DeficienciesGross deficiencies in the crema point to something far out of whack and have the highest correctionpriority. However, the blend itself may have unusually light, dark or thin crema; so when you noticethese defects, taste the shot to confirm the problem.Too light and large bubbles: If the shot is less than 20 seconds, re-read the last section and set the grinderproperly. If the shot time/volume was correct, the machine is running drastically cold and requires immediatecorrection. The taste will be very thin and sour.Almost black, or a black outer ring with tiny bubbles and thin crema: If the shot took forever to produce afew drops, reread the last section and correct the grind. Otherwise the machine is running drastically hot andneeds immediate correction. The taste will be very bitter and burnt.Good color, but thin and quickly dissipating: keep the extraction in the optimum crema range, especially withdark roasts, but usually it's old beans. Rarely, it can show a defective pump not developing sufficient pressure. Inthis case, the taste will be balanced, but weak and with a watery mouthfeel.Taste FlawsThese taste flaws ruin the shot. Correcting them takes precedence over working on the taste balance.Lemon peel: This can be a blending or roasting error and irreparable. Short term, start-dump the shot. Longterm, set the temperature higher and make sure the grinder burrs are sharp. This flaw comes from fines of veryhigh quality coffees, and good blends tend to flirt with it.Metallic: Recently cleaned machines or brand new ones can have this. The taste is eliminated most quickly byflushing more after cleaning, or for new machines, pulling a lot of shots and dumping them. Dull burrs are anothercause. Finally, a failure in the water treatment resulting in almost distilled, low mineral water will cause this.12 hours on the hot plate taste: Time to backflush and clean the portafilter. Verify the frequency of yourcleaning schedule.Instant coffee taste: The mark of overextraction. Grind coarser and stop darker, so volume stays the same. Ifthe bitter taste is prickly-sharp rather than dull, also lower the temperature.Thin and sourish: The mark of underextraction. Grind finer and stop lighter, so the volume stays the same. If thetaste is extremely sour, also raise the temperature.Salt or MSG: A common defect in Indonesian or slower roasted coffees, and difficult to correct. It is amelioratedby high crema content and sweet, ristretto shots, so dial-in exactly to 1.5 ounce, normal-stop color shots. If that
fails, also start-dump, since the taste is slightly more concentrated there. Finally, strong flavors, particularly acidicones, can cover the salt taste. Consider lowering the temperature to enhance these, if the blend's flavor balancepermits. The best solution is to find higher quality Indonesians for the blend and/or speed up the roast finish.Ashiness: Usually a flaw in rapidly dark roasted, low grown coffees. Drop the temperature to the low end of theespresso range. Dial in to the lungo end of the optimum crema range and dark stop the shot (you may be under20 seconds when you do this, that's OK). These measures will not much reduce the ashiness, but will mask theproblem with a little more brightness and crema. The real solution is to change blend.Rubber or Iodine: Buying cheap coffee? This is the classic reason for start-dumping.Sewage, decay, mold, sausage or cabbage smells: This is from badly fermented coffee. If the blend isnormally good, it's from a stinker bean. Clean out the doser and burrs. If it keeps happening, there's nothing youcan do except get new coffee. The importer slipped the roaster a bum bag, and the problem has to be resolvedthere.Unbalanced TasteWhen the crema is right and the shot has no taste flaws, you can fine-tune the setup and extraction toprovide the most harmonious and balanced taste possible. Although everyone wants balanced taste, theexact combination of sweet, bitter and sours tastes that any person considers balanced is extremelyvariable. So these adjustments will be subjective; and there may be more than one optimum set up forthe blend, especially if it is complex in taste.Not sweet enough: Do more ristretto shots, grinding finer and stopping at the same color. This will take the shotout of the optimum crema range, so it has to be a good crema blend. You can also center cut the shots, however,this will reduce the distinctive flavors and can lead to blandness. On the other hand, somewhat bland center cutshots are good way to serve newcomers to straight espresso; or those who prefer more subtle flavors.Over-intense flavors: Lower the pump pressure. If this is because there's not enough sweetness to balance thebitters and sours, use the previous fix. Also consider going more lungo with the same stop color.Pallid Flavors: Raise the pressure. Also consider going more ristretto with the same stop color.Overly sour: Raise the temperature. Short term, trying stopping lighter and grinding finer to keep the volume thesame. If it's really bad, start-dump.Overly bitter: Lower the temperature. Short term, try stopping darker and coarsening the grind to keep thevolume the same.Pursuing the GodshotIf you've never tasted great espresso, you may have read the last section and asked yourself how youcan do all the diagnostics. You have good taste, otherwise I can hardly imagine how you've read this far.Good espresso isn't a punch in the mouth, but tastes wonderful. Expect that, trust your taste andjudgment, and make the adjustments accordingly. Then taste the results. You'll improve very quickly.To further develop that taste, it greatly helps to sample top flight espresso and get a feel for all itspossibilities. Take every opportunity to visit good cafés and roasters, and try their espresso and blends.Ask the coffee people there what you are tasting and how to tell if it's right. Don't worry about gettingbad information—it's a lot easier to recognize a good coffee person than a good coffee because theirenthusiasm gives them away.You can go further by drinking top flight estate coffeesbrewed regularly and learning how the coffees fromdifferent places in the world vary. In comparison to wineand other gourmet items, coffee is the most economicalof the truly great taste experiences. Deepen yourappreciation even further by home roasting you own
coffees and blending them for espresso, or taking part at tastings conducted by roasters.There is a large variety of espresso equipment, and it's useful to know something of the possibilities.These are discussed in great detail on the coffee Internet sites (see the resources and the rest of thissite). If this interests you, participate in these discussions. There are frequent get-togethers that areorganized via these sites, so you will also get some hands on experience.Espresso is a social world. If you want to turn this into a serious hobby, join the Specialty CoffeeAssociation of America (SCAA), attend conventions and barista competitions, get to know others likeyourself, as well as the stars of the business. If you like espresso and coffee, I guarantee you'll enjoythe activity and like the people you meet.Finally, coffee is a big global business. It encompasses large numbers of very poor farmers whoselivelihoods are frequently in the balance, a few very big businesses buying from them cheap and cuttingquality, a mass public that doesn't know much about coffee except that it's a pick-me-up, and a group ofenthusiastic drinkers and purveyors who love coffee. As enthusiasts, it's incumbent on us to convey toothers how rewarding good coffee can be. If we don't understand the coffee trade and its issues, and ifwe don't foster a wider appreciation of good coffee, many farmers will suffer, some of the world's greatcoffees may disappear, and we will all be the poorer for it.Barista Technique:Frothing MilkMilk drinks are only a small part of Italian espresso culture; whereas in most of the US, people haveoversized milk drinks that even an anthropologist would never classify as cultured. But in a few cafésaround the world, baristas are using milk as a paint and espresso as a canvas to create beautiful andwonderful tasting latte art.The best and most practiced professional baristas can create quite stunning patterns that a home baristawill not be able to emulate. But with some months practice, you can learn to properly froth the milk, andpour basic heart and rosette patterns in 6 or 12 ounce cups. There is no easier way of convincing yourfriends of your espresso expertise than casually serving them an artfully poured latte.Correctly frothed milk = microfoam = wonderful cappuccinosProper cappuccinos and lattes require microfoam—a pourable, virtually liquid foam that tastes sweet andrich. The pouring consistency runs from completely liquid for latte art to a slightly thickened sauce fortraditional cappuccinos. If the foam becomes thicker, like soft peak beaten egg whites, its taste turns tocardboard, and its appearance in the cup suffers. Microfoam in the pitcher does not look like a foam,since the bubbles are too small. The only distinction it has from liquid milk is a soft, slightly spectralsheen in the right light. If the frothed milk has visible foam, it was incorrectly prepared. The picturebelow shows a bad foam (left) and a slightly thick microfoam suitable for cappuccinos (right).
Contrasting texture of poorly frothed milk (left) and properly frothedmicrofoam (right)Frothing milk to a microfoam is very simple when you know how to do it, but it does take time to learn.Two processes occur when milk is frothed: first, when the tip is at the right depth, the milk is convertedto microfoam; second, the milk is heated. These two do not happen at the same rate on every machineor tip design, so the point at which you transition from foaming the milk to simply heating it varies frommachine to machine. Finally, the amount of steam varies from machine to machine too, so the timespent to heat enough milk for a six ounce cappuccino can go from 10 to 40 seconds.Four things to learnWhere to put the tip: There are three zones distinguished by sound. In the first zone nearest thesurface, the tip makes a bubbling noise and as it gets slightly deeper, a sucking or tearing noise. In thesecond intermediate zone, there is very little noise. In third zone near the bottom of the pitcher, themilk begins to roar loudly.The tip should stay in the second, silent zone for the entire process. In order to create microfoam,position the tip at the top boundary, so you occasionally hear a sucking/tearing noise. Too much of thesucking/tearing noise and the foam will stiffen and not be micro enough. To just heat the milk after thefoaming is done, position the tip near the lower boundary so you occasionally hear a roaring noise.The milk in the pitcher should whirlpool or form a standing wave of turbulence in order to fold foam intoliquid. With a one hole tip, angle the entry, and keep it close to the edge of the pitcher to rotate the milkinto a whirlpool. With a multi-hole tip, point it straight down and keep it near the center of the pitcher—the hole dispersion pattern on a properly designed tip will create a whirlpool or a standing wave ofturbulence for you. If your multi-hole tip does not do this, change it for another, or block some holesand convert it to slower, single hole use.How long to foam: As the liquid turns to foam, the volume of the milk increases. This is calledstretching. Keep foaming until the milk has gone up about 50% in volume. If you foam more than that,you will get a light microfoam for the classic cap-on-top cappuccino, but latte art will be impossible.
Typically, the side of the pitcher will be lukewarm (40°C, 100°F) at this point. However, volume increaseis a far more reliable indicator, and with some frothing setups, one even keeps the tip at the foamingpoint until the milk is fully heated.How much longer to heat the milk: The milk should be heated to about 70°C (160°F), which is justbelow the point where protein curdles and the foam is destroyed. The easiest way to do this is to holdone hand on the side of the pitcher and stop when it gets uncomfortably hot. If the milk suddenlyincreases in volume, the proteins are curdling, and you've gotten it too hot. With experience and aslower frother, you can hold the pitcher by the side rather than the handle and have your other handfree (it also helps to have a higher pain threshold!).How long to wait before pouring: This topic is treated fully in the next section, Pouring Latte Art.Barista Technique:Pouring Latte ArtIf you followed the instruction on the previous page, the milk will initially be very liquid and will hardlymark the surface of the espresso. After about 10 to 20 seconds, it will thicken to the right point for welldefined latte art. After about 20 to 25 seconds, you can pour something with blurry shapes, a middlething between a cappuccino and latte art. After that, a simple round cappuccino foam cap will form.Swirl the mug a few times and rap it gently against the counter just after frothing and just beforepouring.On a single boiler home machine, some people prefer to froth first and then make the espresso. In thiscase the milk will stand about one minute. In order to keep the foam capable of latte art, reduce theinitial stretch to about 33% and frequently swirl the pitcher while you wait.Steps to pouring latte artThe prevailing usage calls a drink of any size with latte art patterns a latte. If a drink of any size with ashallow cap of soft foam on top is called a cappuccino. A drink with a hard foam cap is called ruined.The exception is the macchiatto, which is a ristretto espresso with about one ounce of milk either incappuccino or latte art form, depending on your wish, and the barista's whim or skill. Good cafés will notserve anything in larger than a twelve ounce cup. I and most purists frown on any milk drink larger thansix ounces.If you are pouring a cappuccino, let the frothed milk rest for 30 seconds prior to pouring. A cap of softfoam will form automatically. The softness of the foam cap is a check on how well you've microfrothed.Do not attempt latte art until you get the soft foam cappuccinos, since this confirms that you arefrothing correctly.Below are the steps to pouring latte art:Turn the handle of the cup to the left and turn the saucer away from you if it has lettering. The setup should befacing the person being served.Let the frothed milk sit 10 to 20 seconds.Tilt the cup towards yourself until it is close to spilling. The more the tilt, the more quickly the milk will mark thesurface (rather than sinking out of sight).Slowly start pouring the milk at the lower end (closer to you) until you see a cloud of white billowing up.For a heart, move the pour towards the center, and oscillate it side to side.
For a rosette, move the pour to the far end and zig zag it towards your end.End the pour with a very light stroke away from you to the far end of the cup.As you pour the milk, level (untilt) the cup smoothly so nothing spills.The rosetta in a cappuccino (left) and macchiatto (right)All this sounds easy, but requires constant practice. If you are a natural, it will take a few weeks,otherwise a few months. Larger drinks are easier to pour than smaller ones. My conservative advice is topour only drinks you consume or serve, and let your expertise grow gradually. If you are in a hurry, buya few gallons of milk, a lot of coffee, and just churn out lattes till you have it down pat. Getting a coachwho knows how to do this, or watching some of the videos, will help a lot.Espresso MachineCleaning and MaintenanceSome people behind the counters in cafés are not even allowed to adjust their grinders, let alonemaintain their machines. They learn so little about espresso that they will be replaced by automaticpush-button machines. Professional or home baristas who pride themselves on their espresso shouldknow enough about espresso machines to keep them in good condition.CleaningEach time you make an espresso, coffee grounds get on the screen and rubber gasket in the group.Some people recommend the "portafilter wriggle," that is, running water and wriggling the emptyportafilter between shots to take care of this. However, this will not prevent gunk from accumulating onthe gasket. Use a grouphead brush regularly (preferably after every shot, but minimally once a day forhome use) to clean the group gasket.
Brewed coffee diffuses up the water path into the group during the extraction process. With time, thecoffee oils accumulate and impart a stale coffee taste (a prickling on the palate) to every shot.Backflushing the machine removes this buildup. This is done by inserting a blind basket (a basket withno holes) into the portafilter, adding a teaspoon full of espresso machine detergent and running thepump for fifteen to twenty seconds. Typically this is repeated about five times without adding newdetergent, followed by five plain water backflushes to rinse. Some people claim that just using a plainwater backflush without detergent more frequently achieves the same goal. I have not found this to betrue, and since coffee oils are insoluble in plain water, I see no reason why it should be. For home use,backflushing every two weeks or so is sufficient, while a caféneeds to do it nightly.water through it.Backflushing only works on machines with a 3-way exhaustvalve (these whoosh at the end of the shot and release thepressurized water remaining in the group into the drip tray).Smaller home machines do not have these. Such machinescan be cleaned by placing a detergent such as CleanCaf inthe tank and running it through the entire machine.Afterwards, the machine is rinsed by running lots of cleanCoffee oils also accumulate on portafilters, especially in the spout. You should let them soak overnight ina bowl filled with water and a table spoon of backflush detergent. Cafés do this every night, but onceevery week or two is enough for home usage.Grinders should be cleaned by disassembling the burrs and blowing out the grind chamber withcompressed air or a shop vac. When using compressed air, it helps to work with a plastic bag over thetop the grinder since a lot of coffee flies around. Once a year, grind through some white rice to clear outthe coffee oils accumulating on the burrs. After doing this, grind through some sacrificial coffee to clearout the rice powder.MaintenanceAs the owner of a home machine, you should be able to change out the group gasket and screen, fixminor leaks and electrical glitches, and flush and descale the machine. However, the details of this aremachine dependent. Refer to your owner's manual, the links in this article, and the resource section onthis site.Conclusion and ResourcesThroughout this piece, I urge people to talk to coffee professionalsand other hobbyists, to try the famous espresso blends and cafés,and even to home roast, cup and blend for themselves. Ten yearsago this would have been virtually impossible; five years ago,
difficult. But since then the coffee Internet has exploded. It has put coffee enthusiasts from all aroundthe world in touch with each other, circulated new knowledge more widely and more rapidly than everbefore, and created a market large enough so several Internet vendors specializing in coffee relatedwares can make a living and provide us with a dizzying selection of state of the art items. The Internethas created a golden age for hobbyists in general, and for coffee hobbyists in particular.There are thousands of coffee related sites. Here is a very short list of some of the major ones, as wellas some of my favorites, organized by type.Information and Review SitesCoffee FAQ: Everything you ever wanted know in a handy format. Thanks ScottCoffeeGeek: Espresso Wunderkind, Mark Prince; features equipment reviews and many more consumer reviewsHome-Barista.com (this site): High-end espresso equipment reviews for the home market and how to'sCoffee Review: Ken David's, the popularizer of homeroasting, monthly reviews of roast coffeesCoffeeCuppers.com: Jim Schulman's and Bob Yellin's expert green coffee reviewsCoffee History: Mommy, why are those goats dancing?Schomer's Table: The thoughts of the original Seattle espresso guruHV's Comprehensive Coffee Links: You wanted more links?Espresso Italiano: If you want the official Italian, and quite poetic definition of espressoThe Coffee Research Organization: a useful information website on coffee basics including espressoWater FAQ: not really up to this standard; but I wrote it, so it's in.Newsgroups and ForumsAlt.coffee: the first Internet coffee hangout. web access via GoogleCoffeeGeek Forums: Only a few years old, but closing fast.Home-Barista.com Forums: New kid on the block, but worth checking out (especially if you wish to comment on oroffer corrections for this article).Roasters and cafésRiley's Coffee and Fudge: Barry Jarrett, the owner, is the first pro who took notice of people talking coffee on theInternet. So Riley's is hereby named the official café/roaster of the Coffee-Internet. Also, June's fudges areso good, they might start an Internet of their ownIntelligentsia: In my hometown, Chicago. Great coffee, great peopleGillies: New York's Don Schoenholt is one of the founders of specialty coffee, and a great supporter of coffeeenthusiastsDallis Brothers: Gillies NYC competitors, also terrific peopleGimme Coffee: There's good coffee descriptions, there's bad coffee descriptions, then there's Gimme'sdescriptions. But the educational material is solid enough for a bankerCounter Culture Coffee: Real espresso in the Old South? You bet. Another great supporter of us enthusiastsHines Public Market: Seattle Haut café. Seattle is the center of North American coffee cultureZoka: More SeattleCafé Victrola: More SeattleCaffé D'Arte: You guessed itEspresso Vivace: Last but not least Seattle. There's lot's more, but I'm tired of typing SeattleStumptown: In Portland; one of the best in North AmericaSupreme Bean: LA's roaster to the stars; nevertheless, their espresso blends are great.Home Roasting and Green CoffeeSweet Maria's: Not just a vendor; but the Free University of home roasting too.Coffee Bean Corral: Russ sits on a Hawaian porch sipping coffees. The ones that fit, he sells.Coffee Wholesalers: Chuck is a roaster who sells some of his stock green, and occasionally makes neat gizmos forhome roastersCoffee Project: James' list is available to home roastersGreen Coffee Coop: 5lb minimum lots at coop prices, vetted by Bob Yellin, the best amateur cupper I know.Internet Coffee Equipment Vendors
Whole Latte Love: One of the original Internet home coffee equipment vendors1st-line equipment: The other originalChris' Coffee Service: A commercial coffee equipment retailer who also sells high-end home equipmentPersonal Websites and BlogsBread, Coffee, Yoga, and Chocolate: if there's a role model for coffee enthusiasts, it's FortuneEspresso! My Espresso: The ultimate love story: boy meets espresso machine ... But seriously, Randy's site hastons of solid info on everything an espresso lover wants to knowGod Shot: Chris Tacy's blog. He is a "3rd wave" barista: a taster, a roaster, and an officer of the Barista Guild ofAmerica.Professional AssociationsSCAA: Specialty Coffee Association of America. The industry group for real coffee. Join as a consumer-memberNCA: National Coffee Association. The enemy. Industry group for Folgers, etc.Barista Guild of America: A new association formed by enthusiastic and knowledgeable professional baristasRoasters Guild: The association for professional craft roasters.