Milk in the refrigerator: what you need to know
Milk is one of the most sensitive food products kept in the refrigerator – its shelf life depends very much on the variety, how it is stored and its packaging. Here you can find out how long open and unopened milk will stay fresh, what the differences are between fresh milk, ESL milk and UHT milk and the correct way to interpret the best-before date. The storage conditions such as the temperature, light and hygiene also have a decisive impact on quality.
The key points
- Open milk: Fresh for three to four days, ESL five days, UHT milk seven days
- Unopened milk: Fresh for seven to ten days, ESL up to three weeks, UHT milk several months
- Refrigerator temperature: 5–7 °C is ideal
- BBD is not an expiration date – use your senses to test
- Spoiled = sour, lumpy, bitter, musty, packaging bulging
What influences the shelf life of milk in the fridge?
The shelf life of milk is determined primarily by its storage temperature, the way the milk has been treated and the condition of the packaging. It’s ideal to have a constant 5–7 °C so that bacteria only grow slowly. Even though the refrigerator door is slightly warmer, milk can generally be stored there – but it’s really important that the packaging always remains well sealed so that no light or foreign odours can get inside.
Temperature fluctuations, for example caused by frequent opening of the refrigerator door or transporting the milk unchilled, will shorten the shelf life significantly. Particularly in summer, milk should remain constantly chilled if possible, ideally in a cool bag. Whatever the variety, heat and oxygen will encourage germs to grow and make the milk go off faster.
How long can open milk be kept in the refrigerator?
Open milk is much more susceptible to germs and should therefore be consumed promptly.
- Fresh milk will usually keep for three to four days after it’s been opened as it is only pasteurised and has therefore undergone comparatively little treatment.
- ESL milk (“Extended Shelf Life”) can be consumed for around five days. It is also microfiltered, which removes some of the germs.
- UHT milk is particularly stable thanks to ultra-high temperature processing and can be kept in the refrigerator for up to seven days after opening.
Despite these guideline figures, the quality and taste may start to diminish earlier. This is why the packaging should always be well sealed and the milk should be placed back in the refrigerator as soon as it’s been used.
How long can unopened milk be kept in the refrigerator?
Unopened milk can be kept for much longer because no germs can penetrate from the outside. The actual length of time depends on how the milk has been treated:
- Fresh milk will stay fresh for around seven to ten days when unopened. Although it is pasteurised, it remains relatively perishable.
- ESL milk can be stored for up to three weeks, occasionally for as long as 24 days without any loss of quality. The additional filtration process extends its shelf life significantly.
- UHT milk is almost germ-free thanks to the ultra-high-temperature processing and can be stored, when unopened, for several months – even outside the refrigerator.
The higher the treatment temperature, the more stable the milk is when it is unopened. Nevertheless, even unopened milk should always be kept well chilled if this is recommended on the packaging.
How long can you continue to consume milk once it has reached its best-before date (BBD)?
Milk can often still be consumed even after the BBD (Best Before Date) has passed if it has been stored unopened and in the correct way. Fresh milk will usually only last a few days longer, whereas ESL milk and UHT milk are often still perfectly good to consume weeks after the BBD.
The BBD indicates how long the quality is guaranteed for, but doesn’t automatically mean that the milk is spoiled. Before you consume the milk, you should subject it to a test of the senses (see, smell, taste). Raw milk or certified raw milk, by contrast, may no longer be used once its use-by date has passed and should ideally be stored in the BioFresh safe.
How can I tell that milk has gone off?
You can tell that milk has gone off from its smell, taste and consistency. Typical indications are:
- a sour or musty odor
- a lumpy or flaky consistency
- a bitter or acidic taste
- bulging packaging
UHT milk can become musty or bitter without curdling or smelling sour. If no change is visible, a quick taste test can clear things up. If the milk has an unusual odour or taste, it should no longer be consumed.
