blastjäähdytys

Blastjäähdytys, or blast cooling, is a rapid cooling method used to lower the temperature of hot foods soon after cooking in order to inhibit microbial growth and preserve quality. It is performed in purpose-built equipment known as blast chillers or blast freezers, which move cold air rapidly over or around the product to accelerate heat transfer.

Cooling is achieved primarily by high-velocity cold air directed at the product (impingement) or by circulating cooled air within an insulated chamber (convection). The food is typically placed on trays or containers to maximize surface contact and promote uniform cooling, with attention to avoiding gaps that could trap warm pockets.

Typical targets involve reducing a product’s core temperature from cooking ranges (roughly 60–75°C) to about 3–5°C within a defined period, commonly around 90 minutes for chilling. For freezing applications, products may be cooled further to -18°C or lower. Exact time and temperature depend on product type, size, packaging, and regulatory standards.

Applications span a wide range of foods, including ready meals, bakery products, meat and fish, dairy, and processed vegetables or sauces. Benefits include reduced microbial growth, preserved texture and moisture, extended shelf life, and streamlined production and cold-chain management. Blast cooling also helps achieve consistent product quality and safer storage conditions.

Key considerations include ensuring uniform cooling, avoiding overcrowding, proper packaging, and maintaining sanitation of equipment. Compliance with HACCP and local food-safety guidelines is essential. Overall, blastjäähdytys is a common and effective method for post-cook rapid cooling in the food industry.