Do you wrap leftovers in aluminum foil? Be careful, these foods are not suitable for it

Aluminum foil is a familiar kitchen helper, but it is not the right storage choice for every food. It remains useful for cooking and for briefly covering many dishes, particularly those that are not highly acidic or salty.

The biggest concern involves foods such as tomatoes, tomato-based sauces, vinegar-heavy dishes, citrus and some meals prepared with wine. Acidity can trigger a reaction with aluminum, especially when food stays in contact with the foil for a long time. The foil may develop small areas of damage, and the food’s taste can change. The amount of aluminum that transfers during normal household use is generally small, but prolonged contact with strongly acidic food can increase the transfer.

Leftover bolognese or another tomato sauce is therefore better moved into a glass container or another suitable container with a lid. The same advice applies to very salty food, particularly when salt combines with acidity and heat. Marinated meat is one example. A marinade containing salt, vinegar, wine or lemon juice is better kept in a tightly closed glass or food-safe plastic container.

Cooling leftovers properly is even more important than the foil itself. Cooked food should not sit for hours on the kitchen counter while it cools completely. Wrapping a large quantity of very hot food tightly in several layers of foil can slow the cooling process. Dividing it into smaller, shallow containers helps it cool faster before refrigeration.

This matters especially for cooked rice, pasta and other starchy foods. Spores of Bacillus cereus can survive cooking. If prepared food remains at room temperature too long, the bacteria can multiply and produce toxins that may cause food poisoning.