If heat kills bacteria, why does cooking and eating expired food still make you sick

Question

Surely the bacteria that grew after the expiration date will have been killed in the cooking process?

In: 15

Answer 1

The bacteria may not all die in cooking, just be reduced to a safe level if we’re talking fresh food.
For expired food, the bacteria levels may have grown so that the proportional reduction by cooking still leaves too high a number (say 1/100,000 left in fresh, 100/100,000,000 in expired) . There’s also accumulation of the byproducts of the bacteria digesting the food that may be toxic- in some booze making processes, for example, the yeast stop when they’ve made enough alcohol to kill themselves if left long enough.