Can You Use Aluminum Foil in the Freezer?

A freezer package has one job: keep moisture in the food and the freezer’s dry air out. By that measure, foil is a good material. Its metal layer lets almost no water vapor through, while thin plastic wrap gradually lets vapor escape; in a package stored for months, that loss dries out the food’s surface. Foil’s other advantage is that it conforms to the shape of the food: when pressed against it, foil fits into folds, leaves no air pockets, and closes off spaces where frost could collect.

Foil’s weakness is durability. Sharp edges on frozen food, rubbing against a neighboring package, or pulling it out of the basket can easily tear the foil. Moisture escapes through a tear in one direction, while air enters from the other. Folded edges can also open over time. For this reason, foil should not be used as a single layer in the freezer. The foil is the inner moisture barrier; an outer resealable bag or lidded container protects it and provides another seal.

Use this order: wrap the food tightly in foil so it clings to the surface, then fold the edges closed. Put the wrapped package in a resealable freezer bag, press out the air, and seal it. Write the contents and date on the outside. These three steps go a long way toward preventing freezer burn on meat, fish, and baked goods stored for months. Small pieces of foil placed between slices or patties also keep them separate and make it easier to remove only as much as you need; you can take a single portion from the freezer without breaking up the block.

There is one exception that is easy to overlook: acidic foods. When tomato sauce, a lemon marinade, or a dish containing vinegar or brine comes into direct contact with foil, it reacts with the metal surface. The foil may develop holes, and the food may take on a metallic taste and develop gray spots. For acidic foods, first cover the food with a layer of plastic wrap and then wrap it in foil, or put it directly in a glass or plastic container and skip the foil.

A few practical details also affect the result. There is no difference between the matte and shiny sides of foil for freezer use; both work the same way. Heavy-duty foil tears noticeably less easily than regular foil and is preferable for packages that will be stored for a long time. It is hard to write on a foil-wrapped package with a marker, so write on the outer bag or on a label. Do not wash used foil and put it in the freezer a second time; once folded, it can leak along its original folds and tear in the same places when wrapped again.