Shelf life
Also known as: storage life, keeping time
Short definitionThe time a food lasts as both safe and saleable when it is stored under a given condition. Temperature is the deciding factor; every day spent waiting in the store comes off this time.
A customer asking for a room is asking for a time: to keep apples until spring, or fish until the end of the season. This time is not a fixed quality of the product; it grows or shrinks with the storage condition. At zero, lettuce waits two to three weeks, fresh red meat one to three weeks and apples three to six months. When temperature rises by 10 K, spoilage runs two to three times faster. Humidity, ethylene, packaging and the state of the product on arrival also shift the time.
In a frozen room a few degrees are worth months. Oily fish lasts 3–4 months at −18 °C but 6–8 months at −25 °C; lean beef waits close to a year at −18 °C. That is why the customer’s target time changes the panel thickness and the refrigeration unit. If the temperature swings, the time gets shorter. A store does not raise quality, it slows the loss; bruised or late-cooled product spoils quickly even in a good room. Goods that come in first go out first, and temperature is recorded continuously.