Pumping and storing breast milk

Reviewed 13 October 20262 min read

How to express breast milk by hand or with a pump, how long it keeps in the fridge and freezer, and how to thaw and warm it.

In short

  • Sterilise the pump and bottle before each use.
  • Fridge at 4C or colder: up to 8 days.
  • Never refreeze milk once it has thawed.

How to express

You can express by hand or with a pump. Try to pick a time when you feel relaxed. Having her nearby, or a photo of her, can help the milk flow. A warm towel or a shower first can help too.

With a pump, start on low suction. Build up slowly. High suction straight away can hurt or damage your nipple. The funnel should fit well. It should never catch or bruise your nipple.

By hand, make a C shape with your thumb and finger, a few centimetres back from the nipple. Squeeze gently, release, and repeat. When the flow slows, move your fingers round or swap breasts.

How long it keeps

  • Room temperature, up to 25C: up to 4 hours
  • Back of the fridge, not the door, at 4C or colder: up to 8 days
  • A fridge you are not sure of, or one at 5C to 10C: up to 3 days
  • Ice compartment of the fridge: up to 2 weeks
  • Freezer at minus 18C or colder: up to 6 months
  • Cool bag with ice packs, after the fridge: up to 24 hours

Storing it

Use a sterilised container or breast milk storage bags. Store small amounts so less goes to waste. Label and date the milk before you freeze it.

If she is premature or ill, ask the hospital staff how to store your milk.

Thawing and warming

Thaw frozen milk slowly in the fridge. If you need it now, stand it in a jug of warm water or hold it under warm running water. Use thawed milk straight away. Never refreeze it.

She can drink it cold from the fridge if she is happy to. To warm it, stand the bottle in warm water. Never use a microwave or the stove, as hot spots can burn her mouth.

Once she has drunk from a bottle of breast milk, use it within 1 hour. Then throw the rest away.

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