It's time for the annual food safety lecture:
What should be said about food safety to this audience
of seasoned home cooks? Got to say something.
Well, the first two of three bottom lines are that bacteria
need temperature and time to grow and give off toxins.
So, keep these numbers in mind:
· The “danger zone” wherein bacteria grow rapidly
is 40ºF to 140ºF, with the highest growth rate
between 90ºF and 110ºF.
· In four hours of accumulated time, in the higher
end of the danger zone, growth of bacteria may occur.
Apply these data to a potato salad scenario for a charity
affair and we have the following:
|| Time the mayo is in the
|Mayo is taken out of the fridge, mixed with Dijon
mustard, diced olives, pickles, onions, lardons of bacon
and whatever and set aside.
|Potatoes are then peeled, cubed, boiled and set aside.
|The eggs are hard boiled and set aside be sliced.
|The potatoes and eggs, now cooled a little, are added
to the mayo.
|The salad—the cooked ingredients are now at about
90ºF—is placed in the fridge to await the trip
to the charity event. It never cools to below 70ºF.
|The salad is loaded into the car and makes the trip
to the charity event where it is placed on the serving
table just in time for the buffet—a two-hour affair.
|There is a good crowd, but plenty of potato salad
for the late arrivals.
Add up the time in the danger zone and we get 5 hours.
The late diners are at some risk from the potato salad!
The third bottom line is “cross contamination”—that is,
the transfer of harmful microorganisms from one item of
food to another by means of surface contact (knives, boards
and hands) or storage and thawing in contact with other
food items. The villains here are pathogenic salmonella
and E. coli, which are the source of most frequently reported
foodborne infections. The heroes are space, soap, water
and cooking temperatures. Prepare and store raw meat
separate from other products. Wash all veggies (Don't believe
the "wash and ready" labels). Wash knives, steels,
boards and hands with soap and hot water upon completion.
Make sure poultry and processed meats (hot dogs and sausages)
are cooked to at least 145ºF
Volume One of Myhrvold's Modernist Cuisine
(see below) has three hugely informative chapters on the
broad subject of Food Safety, all written from an in-depth
perspective of solid science vs. politics, gov't regulators,
agenda activists and conventional wisdom. The chapters are
titled Microbiology for Cooks, Food Safety
and Food and Health. It's 158 pages of informed
material supported with great photos and informative graphs.
A seriously good read.