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Hong KongLearning the temperatures so they stay learned
Learn the principle rather than the list: cooking temperature rises with how much of the food was exposed to contamination. Then drill food-to-number, aloud, in short daily sessions rather than one long one.
People try to memorize five numbers as five unrelated facts. They are not unrelated, and learning the relationship is faster than learning the list.
The principle
Cooking temperature goes up with how much of the food was exposed to contamination.
- 145°F - whole cuts and seafood. Only the surface was ever contaminated, so searing handles it.
- 155°F - ground and mechanically tenderized meat. The surface has been mixed or carried inward.
- 165°F - poultry, and stuffed anything. The pathogen is throughout the bird, or the stuffing insulates the center.
- 135°F - fruit, vegetables and grains held hot. No animal pathogen to destroy, so this is a holding temperature rather than a kill step.
Four numbers, one idea. Anyone who understands that can derive the answer for a food they have never seen on a card.
The holding numbers
135°F hot, 41°F cold, and the danger zone is everything in between.
Notice that 135 appears twice - as the hot-holding minimum and as the cooking temperature for plant food held hot. That is not a coincidence, it is the same number doing the same job.
The two-stage cooling rule
135 to 70 in two hours. 70 to 41 in four more.
The reason the first stage is shorter is that bacteria grow fastest in the upper part of the danger zone. The rule spends less time where growth is fast. Understand that and the two halves stop being arbitrary.
130°F for certain roasts. 45°F for shell eggs. Do not fold them into the main pattern - file them separately, with the specific food attached, because their whole purpose in exam questions is to appear where they do not belong.
How to drill
- Food to number, never the reverse. That is the direction the exam asks in.
- Out loud. Recognizing is not recalling, and only one of them is being tested.
- Five minutes, several times a day, rather than an hour once.
- Mix the foods rather than going down a list, so you are retrieving rather than reciting.
- Include the reason every time, so it stays attached.
Use the kitchen
If you work in one, check things against the numbers as you go. What is the walk-in reading? What is on the bottom shelf? When did that container get date marked?
Retrieval in context is the strongest form of practice available, and you are standing in the context for forty hours a week.
What about mnemonics
They work for arbitrary lists. These numbers are not arbitrary, so a mnemonic replaces a system that generalizes with a trick that does not.
Use one for the Big 6 if it helps. For temperatures, use the reason.
Common questions
What is the easiest way to remember cooking temperatures?
Learn the principle rather than the list: the temperature rises with how much of the food was exposed to contamination. Surface only is 145°F, mixed through is 155°F, throughout the animal is 165°F.
Why is plant food 135°F?
Because there is no animal pathogen to destroy. That figure is a hot-holding temperature rather than a kill step, which is why it is the same number as the hot-holding minimum.
How do you remember the cooling rule?
135 to 70 in two hours, 70 to 41 in four more. The first stage is shorter because bacteria grow fastest in the upper danger zone, so the rule spends less time where growth is fast.
Should you use mnemonics?
For arbitrary lists like the Big 6, they help. For temperatures they replace a system that generalizes with a trick that does not, so use the reasoning instead.
How often should you drill temperatures?
Five minutes several times a day rather than an hour once, food to number, out loud, with the foods mixed rather than in list order.