Food Safety Focus (236th Issue, March 2026) – Article 4

UHT Milk: What It Is and How to Store It

UHT (Ultra-High Temperature) milk and pasteurised milk are commonly available. Despite the word "ultra" in its name, UHT milk is not an ultra-processed food, a topic that has received considerable attention recently. Pure UHT milk is a single-ingredient food that contains no preservatives or other additives. UHT and pasteurised milk are very similar in composition.

The main difference is heat treatment. Pasteurised milk is heated at a lower temperature (e.g. 72 °C for >15 seconds) which reduces harmful bacteria but does not eliminate all spoilage microorganisms, so it must be kept chilled. UHT milk is heated to a much higher temperature for a short time (e.g. 132 °C for >1 second) which destroys virtually all microorganisms. Therefore, unopened UHT milk is shelfstable and can be stored at room temperature until the expiry date. Once opened, UHT milk should be refrigerated at 4 °C or below, and consumed within the period stated on the packaging (usually two to seven days). To ensure it is used in time, mark the carton with the opening date and always check for signs of spoilage (sour smell, texture changes) before consumption.