Schnellgefrieren

Schnellgefrieren, or rapid freezing, is a technique used to freeze foods and other materials quickly to preserve quality. By lowering temperature rapidly, it limits the growth and enlargement of ice crystals, helping retain texture, flavor, and nutrients during storage.

Common methods include air-blast freezers that circulate cold air, plate freezers that freeze by contact with cold surfaces, and cryogenic freezers that use liquids such as liquid nitrogen or carbon dioxide. Individually Quick Frozen (IQF) systems apply strong air jets to freeze each piece separately, producing loosely separated items. Typical operating temperatures for blast freezers are around -25 to -40°C; plate freezers reach similar ranges; cryogenic systems can reach much lower temperatures, enabling ultra-rapid freezing.

Benefits include reduced formation of large ice crystals, minimal dehydration and freezer burn, better retention of color, aroma and nutritional value, and longer shelf life. Rapid freezing also enables processing of large quantities with consistent quality.

Applications occur in the food industry for meats, fish, berries, vegetables, and prepared meals, as well as in laboratories and biobanking for preserving biological samples through ultra-rapid cooling.

Limitations include high equipment and energy costs, the need for proper packaging and handling to avoid moisture loss, and specialized monitoring to ensure uniform freezing.