Modernist-Cuisine-Vol.-1-Small

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Ultrasonic baths are fast, thorough,
and nearly labor-free tools for
cleaning small items. Jewelers use
them to refresh the surface of
precious metals, because the
cleaning process is so gentle. In the
kitchen, ultrasound provides
a handy way to clean small, delicate
parts, such as siphon nozzles and
injection needles, that don’t easily
come clean with a soapy sponge.
T H E CON TROV ERSY OF
Cutting Boards: Wood or Plastic?
filling a bucket and completely submerging your
tools in it or filling a lidded container halfway and
then flipping it for another two minutes so that the
parts of your implements that were previously
exposed become submerged. It also means opening
shears and other tools with mating surfaces
before submerging them. After you drain the
bleach solution, do not rinse the implements or the
holding container with water. You will invariably
recontaminate them if you do so. Don’t use a towel
to wipe off the implements, either. Let everything
drip dry. Any residue of bleach that remains will
be so faint that it will not affect the taste or the
safety of food.
You might object that carbon-steel knives will
rust if they’re not thoroughly dried at the end of
the night. If the knives won’t be used again during
a shift, you can wipe them dry with a paper towel,
but it’s a good idea to spray them again with the
200 ppm solution the next day and let them sit wet
for two minutes before using them.
For heavy disinfection, use a 1% bleach solution,
which will essentially kill bacteria on contact. This
translates into a 525 ppm solution or, for typical
One timeless debate of food safety concerns the relative
merits of wood versus plastic cutting boards. Both materials
have their advantages and disadvantages, but we prefer
wood. Plastic is easy to sanitize and run through a commercial
dishwasher, and some versions are color-coded to help
cooks segregate food and avoid cross-contamination.
Because of these attributes, some jurisdictions permit only
plastic boards.
Research suggests, however, that wood has natural antibacterial
activity that helps to disinfect the board surface. True,
water may not be able to permeate deep scratches and scars
in the wood, due to surface tension. But cut wood secretes
antimicrobial compounds that help keep those fissures clean.
For the rest, you can scrub wood with salt as a scouring agent,
then rinse it with a 200 ppm bleach solution.
Many kitchens soak their cutting boards in a bleach solution
overnight. That’s not appropriate for wood. But be aware
that plastic floats, so to ensure proper sanitization you must
household bleach, a 1:100 dilution with water
(equivalent to 10 ml added to 1 l of water, or about
three tablespoons of bleach per gallon of water).
Put the solution in a spray bottle labeled for safety,
and apply it directly to refrigerator shelves, counters,
floors, and heavy-duty equipment like meat
slicers for prompt and thorough disinfection.
Unlike the weaker version, this 1% solution
requires a clean-water rinse to remove the bleach
residue. The rinse requirement creates its own
problem, of course. One work-around is to have
a separate spray bottle of sterilized water; use it to
spray down the bleached surface, then wipe the
surface with a paper towel.
If you can’t rinse the bleach off, you shouldn’t
use a 1% solution. You might also be understandably
reluctant to use the heavier solution on
stainless steel. Fortunately, major commercial
suppliers such as Quantum sell other, equally
effective chemical cocktails designed for sanitizing
kitchen surfaces. A good supplier will be able to
recommend bleach alternatives for stainless-steel
counters and utensils. Avoid the cheaper products,
as some can contaminate the flavor of meat.
weight down plastic boards until they’re completely submerged.
Also, if you stack the boards horizontally, the bleach
solution may not be able to get between them.
A growing number of companies also sell
ultraviolet light kits for sterilizing boards, knives,
and other utensils. These kits use shortwave
(UVC) ultraviolet light to kill up to 99.99% of
most viruses, bacteria, and mold spores by damaging
their DNA. Some handheld models sterilize
surfaces with as little as 10 seconds of exposure.
UV light can’t kill germs in cracks or shadows,
however, so turn food and equipment to expose all
surfaces. Note that exposing food to UV light for
too long can change the flavor, and you should
minimize your own direct exposure to the light.
Some industrial food processors use HEPA
(High Efficiency Particulate Air) ventilation hoods
to maintain sterility while food is being handled.
For the typical home or restaurant kitchen, these
hoods may be too expensive to be practical.
Temperature Control
People do dumb things to their refrigerators and
freezers. Studies show that some adjust their
refrigerator temperatures based on the weather:
down in hot weather and up in cold weather.
Cooks who should know better store warm dishes
on refrigerator shelves or linger in indecision at an
open freezer door.
Refrigerators and freezers are somewhat
delicate instruments, and keeping them functioning
optimally is vital to food safety. Refrigerators
in particular are prone to temperature spiking up
to as much as 15 °C / 60 °F. If they lack fans to
circulate air, their temperatures can vary from the
top to the bottom shelves as well.
This is a special concern with some of the
smaller, energy-efficient refrigerators popular in
Europe. The temperature in these “passive”
refrigerators can take hours to recover after
a warm dish is placed on one of their shelves.
Temperature swings are far less of a concern in
freezers, because at the typical freezer temperatures
of −20 °C / −5 °F, no microbes grow.
There are a few measures you can take to
minimize temperature swings and variations in
your refrigerator so that you can store your food as
safely as possible. First, figure out the temperature
differential in your refrigerator. No part of your
refrigerator should be above 5 °C / 40 °F. Recognize
that refrigerators with internal fans are better
at maintaining an even temperature, so if your
refrigerator lacks one, you can expect greater
variation. If the only way to get your top shelf
down to 3 °C / 37 °F is to have the bottom at
a freezing temperature, so be it. Minimize the
number of times you open the door, and close it
again as quickly as possible. And never put hot food
in a refrigerator.
Counterintuitive though it may seem, it’s
generally safest overall to cool hot food outside of
your refrigerator. One common approach is to take
advantage of the free cooling capacity of the air in
your kitchen. Because the efficiency of heat
transfer is proportional to the difference in temperature
between food and air, letting the first 20 °C /
40 °F of cooling happen outside your refrigerator
could translate into big savings on your energy
billand it will keep your refrigerator from getting
Aquariums work well as holding containers
for sanitizing cooking utensils. Submerge
the utensils completely, so that the
bleaching solution contacts every surface.
When using low cooking
temperatures, remember that
an accurate thermometer is
critical because even small
temperature changes can
require sizeable differences in
the corresponding cooking
times.
204 VOLUME 1 · HISTORY AND FUNDAMENTALS
FOOD SAFETY 205