Bacterial growth in the kitchen

A bacterium can divide into two every 20 minutes at 25°C, which is roughly the temperature of a kitchen in the late morning. This rapid reproduction can lead to thousands of bacteria in just two hours, increasing the risk of foodborne illness.

Food poisoning in France

According to one report, this rapid multiplication explains why food poisoning remains a significant issue in France, with 2,231 cases reported in 2023, affecting more than 22,000 people and causing 19 deaths. These figures are likely only the tip of the iceberg, with estimates by Santé publique France suggesting that foodborne infections could affect between 1.28 and 2.23 million people annually.

Risks in common foods

No food is immune to bacterial growth at room temperature. Cooked dishes, such as pasta, rice, gratins, and quiches, offer a favorable environment for bacteria like Clostridium perfringens, Bacillus cereus, and Staphylococcus aureus, which are responsible for a significant part of recorded food poisonings.

Eggs and dairy as high-risk items

Eggs are particularly risky, as Salmonella is the most often identified pathogen, found in 42% of confirmed cases, with eggs or egg-based products suspected in nearly 4 out of 10 cases. Homemade mayonnaise, which contains raw egg and is never cooked, accumulates risk factors. Dairy products, including some pasteurized milk cheeses, can also be contaminated by Listeria, with several dozen cases recorded and two deaths associated.

Refrigeration guidelines

Anses recommends not to leave food more than two hours at room temperature before refrigerating it. However, this limit corresponds to moderate conditions, around 20°C. As soon as the temperature rises, such as in a heated kitchen or during periods of high heat, the safety window shrinks drastically.

Ideal storage temperature

The ideal storage temperature is between 0 and 4°C, an interval that greatly slows down or even stops bacterial multiplication. As soon as the meal is finished, it is recommended to head to the fridge rather than the kitchen table, even for some pasta that seems still warm and harmless.

Food safety tips

The key to food safety is to refrigerate food quickly, avoid leaving dishes all night outside, and monitor particularly egg-based or dairy preparations to avoid the majority of discomforts.