The Home Barista's Guide to Espresso - Coffee Prince in Surat

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