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

Because some strains of bacteria produce toxins, and heat doesn’t always destroy those toxic compounds.

If the food has already spoiled, it means the bacteria already ate it and their waste products typically aren’t good for us.

Quick distinction, btw: “expired” isn’t the same as “spoiled.”

At lot of “expiration/expiry” dates on food are actually just “best-by” dates after which the manufacturer no longer guarantees quality, and suggests it’ll be past its peak – it doesn’t mean it automatically goes bad on or after that date (although some stuff, like fresh milk seems to pretty reliably go off soon after that).

ETA: Normal cooking heat doesn’t kill all kinds of bacteria, but in the vast majority of cases, it kills the kinds that make us sick.