Modernist-Cuisine-Vol.-1-Small

THE COMPLEX ORIGINS
OF FOOD SAFETY RULES
3
Proper cooking can substantially
reduce pathogens in food, but it
won’t ward off foodborne illness if
you don’t address the risk associated
with cross-contamination of
other foods and kitchen surfaces.
Scientific research on foodborne pathogens
provides the foundation for all food safety rules.
Generally speaking, two kinds of research inform
us about issues of food safety. The first is laboratory
experimentation: for example, testing how
much heat will kill a pathogen or render it harmless.
Data from these experiments tell us the
fundamental facts about pathogens of interest. The
second kind of research is investigation of specific
outbreaks of foodborne illness. This research is
called epidemiology (from the root word “epidemic”);
it tells us what happens in the real world.
You might think that scientific evidence would
constitute the “last word” when food safety rules
are made, but in fact it’s only the beginning. Policy
makers take many other factors into consideration,
including tradition, cultural trends, political
expediency, and pressure from industry. To some
extent, it’s reasonable to apply these modifiers
because public health, not scientific purity, is the
ultimate goal of food safety regulations. But this
approach sometimes imposes arbitrary and
scientifically indefensible restrictions that limit
food choices, confuse the public, and prevent
cooks from preparing the highest-quality meals.
We’ll devote much of this chapter to explaining
the cumbersome and sometimes dangerous
fallacies engendered by these restrictions.
To complicate matters, some guesswork and
compromise are inevitable in setting safety
standards. Take, for example, the way in which
health officials decide how much the pathogen
count should be reduced when heating food. In
the preceding chapter, we reviewed the terminology
used to describe these reductions. Killing 90%
of the pathogens within a specific food, for example,
is called a 1D reduction (where D stands for
“decimal,” or factor of 10). Killing 99% of the
pathogens is referred to as a 2D reduction, killing
99.99% is termed a 4D reduction, and so forth.
Cooks achieve these reductions by maintaining
food at a given temperature for a corresponding
length of time. The practical impact of an elevated
D level is a longer cooking time at a particular
temperature. If a 1D reduction requires 18 min at
54.4 °C / 130 °F, then a 5D reduction would take
five times as long, or 90 min, and a 6.5D reduction
would take 6.5 times as long, or 117 min. Clearly,
the D levels targeted for food can have a profound
effect on the manner and quality of cooking.
What D level should regulators choose to
ensure food safety? If the food contains no pathogens
to begin with, then it’s not necessary to kill
pathogens to any D level! Highly contaminated
food, on the other hand, might need processing to
a very high D level. Right away, you can see that
Most kinds of raw-cured Spanish hams
(right) are banned in the U.S., even though
there is no prohibition against serving raw
beef such as steak tartare or the raw egg
used to garnish it (far right).
166 VOLUME 1 · HISTORY AND FUNDAMENTALS
FOOD SAFETY 167