Do you usually leave your gratin to cool quietly on the work surface? Bad idea. At room temperature, bacteria proliferate. Explanations.
Lasagna, ratatouille, baked chicken, vegetable curry… Many of us kindly let our dishes cool on the work surface – while waiting to enjoy them later. The problem ? As they cool, they will reach ideal temperatures for the bacteria which will then proliferate, warns Océane Sorel, doctor of virology known under the pseudonym Thefrenchvirologist.
2 hours at room temperature maximum
When you cook a dish and want to eat it later (for example the day before for the next day), it “Don't let it cool in the oven overnight.“, warns Océane Sorel.
In fact, “at room temperature, in the presence of water and nutrients from a food with an optimal composition (non-acidic, low in salt, etc.), a bacterial cell can divide into two daughter cells within approximately 20 minutes and thus give rise to considerable quantities of new cells“, recalls ANSES.
On the other hand, in the refrigerator (+4°C), the majority of pathogenic bacteria are unable to multiply and those, such as Listeria monocytogenes, which can, do so at a very slow rate.
However, can you put a boiling dish in the refrigerator?
No, warns Dr. Océane Sorel.because it risks heating up all the foods in the fridge and promoting bacterial proliferation in these foods“.
“You must therefore find the right balance between: a dish which is not too hot to the point of heating up other foods and a dish which does not spend too much time at room temperature because otherwise bacteria will swarm.“, recommends the expert.
The main thing is to never let the dish spend more than two hours at room temperature before refrigeration, specifies ANSES. Otherwise, there is a risk of being poisoned.
This is also true even when the dishes have been cooked for a long time: “they can contain heat-resistant forms called spores (“Clostridium perfringens” or “Bacillus cereus” bacteria).“, further details the agency.
View this post on Instagram
In the kitchen, what good gestures should you adopt?
Faced with the high risk of poisoning in the kitchen, good actions must be adopted, ANSES reminds:
- “If the quantity of food prepared is large (more than a liter or a kilogram), it must be divided into smaller portions so that cooling is faster“, explains the agency.
- “The remains of meals which have sometimes remained for a long time at room temperature, must be consumed very quickly or thrown away, particularly if they are those of picnicsmeals or festive summer buffets“, underlines the organization.
- “Certain catering products, such as ready-made meals, cream-based pastries, “very perishable” foods sold by the cut and not prepackaged, made by an artisan or sold at retail without mention of a use-by date, as well as prepared meals at home, should not be kept for too long. It is advisable to seek advice from traders; a duration of less than three days is frequently recommended“, warns ANSES.
- “It is recommended to monitor the temperature of your refrigerator and store sensitive foods (especially meats, poultry, fish) in the coldest area.“, recalls the agency.
- “A baby meal or bottle of milk should not be stored for more than 48 hours at +4°C“, concludes the organization.
Slide: Food poisoning: 10 hygiene rules to avoid them
