Ultrapasteurisation

Ultrapasteurisation, or ultra-pasteurisation, is a high-temperature, short-time heat treatment applied to dairy liquids and some beverages. The process heats the product to around 135–150°C (275–302°F) for a brief period, commonly 1–5 seconds, followed by rapid cooling. The goal is to reduce spoilage microorganisms and certain pathogens to extend refrigerated shelf life while minimizing impact on flavor compared with traditional pasteurization.

Unlike ultra-high-temperature processing (UHT), which aims for complete sterilization and allows shelf-stable, room-temperature storage in aseptic packaging, ultrapasteurisation is designed to preserve refrigerated storage requirements. Ultrapasteurized products typically require refrigeration and have a longer shelf life than conventionally pasteurized goods, for example around several weeks to a couple of months unopened, depending on product and packaging.

Common products include ultrapasteurized milk and cream, and some fortified dairy beverages. The method may alter flavor and color through heat exposure, although advances in processing have reduced off-flavors. Equipment commonly used includes plate or tubular heat exchangers enabling rapid heating and cooling, often in conjunction with aseptic packaging lines.

Regulatory definitions of ultrapasteurisation vary by country, but it is generally regarded as a pasteurization variant that strives for greater microbial safety and longer refrigerated shelf life without the room-temperature stability of UHT products. Standards are implemented through HACCP-based control of time–temperature profiles and post-pasteurization handling.