Djupfryst

Djupfryst is a Swedish term used to describe food and other goods that are stored or processed at very low temperatures to halt microbial growth and enzymatic activity. In everyday usage, it is most often encountered on consumer food products such as meat, fish, vegetables, and ready meals. The label implies that the product should be kept frozen until use.

Deep-freezing is typically achieved by fast or blast freezing, sometimes using cryogenic methods with liquid nitrogen or carbon dioxide, to form small ice crystals that cause less damage to cell structure. Temperature targets are usually −18 °C or lower for commercial frozen foods; some products are stored at even colder temperatures (−30 to −40 °C or below) to prolong shelf life or preserve particular textures.

The effect of deep-freezing is to preserve color, flavor, texture, and nutrients better than slower freezing methods. It slows microbial growth and enzymatic reactions, helping to maintain quality during storage. Shelf life varies by product, but properly handled deep-frozen foods can retain quality for months to a year or more depending on composition and packaging.

Handling guidelines emphasize keeping products frozen until use. Thawing should be done gradually in the refrigerator or, for quicker needs, in cold water or a microwave if appropriate for the item. Once thawed, foods should be consumed promptly and not refrozen in many cases, as quality and safety can deteriorate.

In scientific contexts, deep freezing can also refer to cryopreservation at temperatures well below freezing (for example, −80 °C or −196 °C with liquid nitrogen) to preserve biological samples for extended periods.