Food safety

Food safety is common sense plus a few numbers. Most illness at home comes from food left warm too long, raw meat juices on ready-to-eat food, and undercooked poultry, ground meat or eggs.

The danger zone: 5–60°C (41–140°F). Bacteria multiply fastest in this range. Keep cold food cold (fridge at 4°C/39°F or below, freezer at −18°C/0°F) and hot food hot (above 60°C/140°F).

The two-hour rule. Don't leave perishable food — cooked dishes, meat, fish, dairy, cut fruit, cooked rice — in the danger zone for more than 2 hours in total, or more than 1 hour on a hot day (above 30°C). Throw it out if in doubt.

Cooling food quickly

• Divide large batches (stocks, stews, rice) into shallow containers no more than 5 cm deep.
• Cool pots of stock or soup in an ice bath in the sink, stirring now and then.
• Spread cooked rice and grains on a tray to cool.
• Refrigerate within 2 hours. Warm food can go in, as long as it's in shallow containers and the fridge isn't packed.

Reheating. Reheat leftovers until steaming hot all the way through, at least 74°C (165°F) in the center. Bring soups, stews and sauces to a full simmer. Reheat only once. Reheat rice only once, and only if it was cooled quickly; rice can harbor Bacillus cereus spores whose toxin survives reheating.

Thawing. Thaw in the fridge (about 24 hours per 2 kg) or in a sealed bag in cold water changed every 30 minutes. Never on the counter.

Cross-contamination

• Use a separate cutting board for raw meat and fish, or wash it thoroughly in hot soapy water before using it for anything else.
• Wash your hands for 20 seconds with soap after handling raw meat, fish and eggs.
• Don't wash raw chicken. It sprays bacteria around the sink; cooking kills them.
• Store raw meat and fish on the bottom shelf of the fridge, covered, so juices can't drip onto other food.
• Never put cooked food back on a plate that held raw meat.
• Marinades that touched raw meat must be boiled for at least 1 minute before using as a sauce.
• Wash towels often and replace sponges weekly.

Eggs. Raw and lightly cooked eggs (mayonnaise, hollandaise, mousse, soft-boiled eggs) carry a small risk of Salmonella. Where flocks are vaccinated or monitored, as in the UK and the Nordic countries, the risk is very low, but for pregnant people, babies and young children, the elderly and anyone with a weakened immune system, use pasteurized eggs for raw-egg recipes or cook eggs until both white and yolk are firm (71°C/160°F). Keep eggs refrigerated, and don't use cracked ones.

Raw fish. Fish eaten raw or lightly cured (ceviche, poke, gravlax, sushi) should be very fresh and from a trusted fishmonger. Wild fish can contain parasites; freezing at −20°C (−4°F) for at least 24 hours (or as your national food authority advises) kills them. Ask your fishmonger for fish previously frozen for raw use. Farmed salmon from regulated farms is generally considered low risk. The same vulnerable groups should avoid raw fish and shellfish.

Other notes

• Garlic or herbs in oil, including garlic confit, must be refrigerated and used within 4 days, or frozen (risk of botulism).
• Raw flour can carry bacteria; don't eat raw dough or batter.
• Shellfish: discard mussels and clams that stay open when tapped before cooking, and those that don't open after cooking.
• When in doubt, throw it out. Smell and appearance are not reliable tests for harmful bacteria.