Can I mix breast milk from different pumping sessions?
Yes certainly you can combine breastmilk but there are a few guidelines.
If you are pumping twice in a day, keep the first milk covered in the fridge. Then when you express again, you will need to use a different bottle and then chill that milk before adding it to the first milk.
You should not add your warm breast milk (at body temperature) to the chilled fridge milk. You need to cool the warm breast milk before you add it to the already chilled milk.
If you are expressing over several days, we recommend that you freeze the milk in small quantities to avoid wasting it.
Just make sure you cool down your freshly expressed breastmilk before you add it to the frozen stored milk.
In other words, if you have 50mls pumped, cool it and then add to the frozen supply for the baby’s feed. Only add cold milk to cold milk or cold milk to frozen milk.
Because you never want to waste breast milk, you might consider freezing it in relatively small amounts for each feed. This way, if your baby doesn’t take it all, you won’t be throwing it out, plus it will be quicker to defrost and warm. Read our suggested How Much Does Baby Drink
If your baby does not drink all the milk in one feed – you CANNOT reuse the milk later, you will need to discard it.