Glossary
Vacuum sealing
Removing air from a bag or container before sealing it, which extends freezer life and enables sous vide cooking.
Vacuum sealing is the process of pulling air out of a bag or container before sealing it airtight, usually with a dedicated vacuum sealer machine. Removing the air prevents the oxidation and moisture loss that cause freezer burn, and it also creates the tight seal needed for sous vide cooking, where food cooks in a temperature-controlled water bath.
For meal prep, vacuum sealing meaningfully extends how long batch-cooked meals last in the freezer compared with a standard freezer bag, and flat, vacuum-sealed portions stack and thaw more evenly. When choosing a sealer, check whether it handles both dry foods and moist, liquid-heavy ones like soups, since cheaper models can struggle to seal bags with liquid near the opening.
A common mistake is trying to vacuum seal foods with sharp edges, like bone-in cuts, without extra padding, which can puncture the bag and break the seal. It also helps to freeze very liquid foods partially before sealing, so the vacuum process does not pull liquid into the machine.