The Food Lab: Better Home Cooking Through Science

posing a health hazard, what we’re really talking about is
bacterial content and the toxins they can produce. As meat
sits, bacteria present on its surface will begin to breed and
multiply, eventually growing to a dangerous level. Below
38°F or so—fridge temperature—the bacteria are lethargic,
multiplying very, very slowly. Take the meat all the way
down to freezing temperatures, and the water necessary for
the basic life functions of a bacterium turn into ice, making
it unavailable to them. That’s why frozen meat can last for
months, even years, if properly sealed.
But when meat gets warmer, the bacteria become more
and more active, and they will continue to do so until
they’ve gotten so hot that they die. This kill-temperature can
vary from bacterium to bacterium, but in general it’s around
120°F, with the very hardiest (Bacillus cereus) finally
kicking the bucket at around 131°F.
Ah, you’re thinking to yourself, so I only need to cook my
meat to 131°F for it to be safe. Well, yes and no. Just like
cooking, destroying bacteria—the process of pasteurization
—takes both temperature and time to accomplish. (See
“Chicken Temperature and Safety,” here.)
With a temperature-controlled water bath, you have the
ability not only to cook chicken to lower temperatures, but,
more important, to hold it there until it’s completely safe to
consume.
What does this mean for a home cook? It means that you
no longer have to put up with dry 165°F chicken.
A chicken breast cooked sous-vide to 140°F and held for
25 minutes is just as safe as chicken cooked to 165°F, and
incomparably moister and more tender. It glistens with