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Handbook

Fried rice and Bacillus cereus

Why cooked rice left at room temperature can poison you even after refrying.

Bacillus cereus spores survive the boiling of rice. If cooked rice sits warm, the bacterium multiplies and produces a toxin that is NOT destroyed by reheating — so frying it well does not save you here. The same applies to pasta and grains.

How to stay safe
  • Rice you do not eat right away: cool it and refrigerate within an hour of cooking.
  • Keep cooked rice refrigerated for a day at most; for fried rice use exactly that — yesterday's, from the fridge.
  • Do not leave the rice cooker on keep-warm for half a day.

This is a reference, not medical advice. With poisoning symptoms see a doctor; when in doubt about a product, throw it out without tasting.