There are a number of reasons for the confusion about how long fresh breast milk will keep.

More and more research in the subject is happening. The latest research shows that milk can be kept up to seven days. For older research it says 24 hours or 48 hours. This isn’t because milk now lasts longer but because they set a time limit on the research for the earlier studies – I don’t think they imagined that breast milk could keep so long. Part of the reason the milk keeps so well is because of all the anti-germ agents in it. These kill the bacteria in the milk and so protect your baby from illness.

Also remember that guidelines for hospitals and home use are different. Often hospitals will set a limit of 24 hours. They are concerned about cross contamination – after all there are lots of germs in a hospital. Your milk will already have the antibodies to all the germs in your home so these germs pose much less of a threat to your baby.

The guidelines give the suitability of the milk from how much bacteria there is in your milk (it has been found that there is less bacteria in stored milk that in newly pumped milk – as the antibacterial agents have more time to work on the milk!) But the milk can also turn rancid – where the fat is broken down. It is very similar to butter going rancid if left out of the fridge on a hot day. When this happens the babies usually will not accept the milk – you can usually tell from the funny smell of the milk. How quickly your milk turns rancid depends on your individual milk. I know lots of mothers who can keep their milk for seven days, others who can only mange three days and a few who can only mange 24 hours.

If you find that you milk does turn rancid quickly contact me as scolding and freezing the milk is one answer to the problem. The upsetting thing is that the milk can turn rancid in the freezer. The fat breakdown process is slowed down by the cold environment but not stopped.

Best wishes,