Shelf life of the milk
The shelf life of milk depends heavily on its processing and storage conditions, with pasteurized milk requiring refrigeration while ultra-high-temperature (UHT) milk is shelf-stable. Pasteurization uses moderate heat to eliminate harmful bacteria, giving refrigerated milk a typical shelf life of 5–10 days. UHT processing, however, uses higher heat to kill all bacteria and spores, allowing unopened UHT milk to last for months at room temperature.
Proper home storage is critical to achieving maximum shelf life. Keeping milk consistently refrigerated below 40°F (4°C), storing it on an inner shelf instead of the warmer door, and keeping it sealed away from strong-smelling foods can all help extend its freshness. Signs of spoilage, regardless of the printed date, include a sour smell or curdled texture.
