Many believe this myth, but the truth is different

A recent article from Novi list has clarified a common misconception regarding food safety: freezing does not kill all bacteria. Many believe that the low temperatures inside a freezer can eliminate all microorganisms, but this is far from the truth. Freezing significantly slows down the spoilage process, yet it is not a method of sterilization. This misunderstanding is one of the most frequent when it comes to food safety. The reality is that freezing only temporarily "puts bacteria to sleep," rather than killing them outright. When food is thawed, many of these bacteria become active again and, under favorable conditions, continue to multiply as if they had never been frozen. The key point here is that freezing does not destroy all microbes, which means that food stored in a freezer should still be handled with care. What actually happens during freezing? At around -18°C, which is recommended for home freezers, bacterial growth nearly ceases entirely. This means that microorganisms cannot reproduce, allowing food to be stored for months without significant deterioration. However, most bacteria remain alive during this time. They simply enter a dormant state and resume activity once the temperature rises. Therefore, freezing cannot fix food that was already spoiled before being placed in the freezer. Some bacteria, however, may be killed during the freezing process, especially if large ice crystals form and damage their cells. Nevertheless, certain harmful bacteria, such as salmonella, listeria, and some strains of E. coli, can survive freezing without major issues. For this reason, experts emphasize that freezing should never be considered a method of disinfecting food. Freezing also does not eliminate all parasites. In some cases, such as with raw fish, freezing can help destroy certain parasites, but only if done at sufficiently low temperatures for an adequate amount of time. That’s why professional food producers use industrial freezers that achieve much lower temperatures than typical household units. One of the biggest mistakes occurs after thawing. It is more important what you do when defrosting food than how long it was frozen. If meat, fish, or prepared dishes sit on the kitchen counter for several hours, the bacteria that were dormant will quickly begin to grow again. The safest ways to thaw food include using the refrigerator, a microwave with a defrost setting, or cold running water if the food will be cooked immediately afterward. Thawed food should not be refrozen unless it has been properly heated and cooled again. Finally, freezing cannot improve the quality of poor-quality food. A common mistake is to freeze food that is close to its expiration date or already shows signs of spoilage. Freezing won’t stop processes that have already begun, nor will it remove toxins produced by some bacteria. As a result, it's best to freeze food as fresh as possible, right after purchase or preparation. In conclusion, while a freezer is an excellent tool for preserving food, it is not a means of eliminating bacteria. Low temperatures halt their growth, but most microorganisms remain viable and can become active again after thawing. Thus, proper storage, safe thawing methods, and thorough cooking remain the most critical steps in preventing foodborne illness.