Proliferation of bacteria, food poisoning … Refreezing a thawed product is not without risk to health.
You should know that when food is thawed, simply by leaving it on the worktop for example, the cold-resistant bacteria still alive benefit from optimal conditions to multiply due to the warming of the temperature.
And in the event of refreezing, these same bacteria, potentially pathogenic and dangerous for health, will continue to proliferate in the freezer, because the total cooling of the product then takes place at a slow speed.
1,024 times more bacteria
As the Ministry of Agriculture and Food explains on its website, it is necessary to wait several hours before the food in question is sufficiently cooled to limit their proliferation.
For example, a steak containing a type of bacteria which reproduces every 20 minutes, which has been left for 3 hours at room temperature and takes 3 hours to be completely refrozen, may end up containing 1,024 times more bacteria than it initially did. .
If these are pathogenic, they can then cause more or less serious food poisoning, depending on the type of bacteria and their number. This is why it is better to avoid refreezing an already frozen product.
To limit the proliferation of bacteria as much as possible, it is advisable to thaw food in a refrigerator, even if it takes longer. If the food has been cooked in the meantime and thawed in this way, it may possibly be frozen again.