Storing breast milk: how long it keeps in the fridge and freezer

Expressed milk gives you more freedom: when you go back to work, when someone else feeds your baby or simply when you want to rest. Here's how long it keeps and how to store it so it stays safe for your baby.

Updated 7 October 2026

In short

Fresh milk keeps up to 4 hours at room temperature and up to 4 days in the fridge.
In the freezer it's best used within 6 months.
Never warm it in the microwave and never refreeze it once thawed.

How long breast milk keeps

Milk	Room (up to 25°C)	Fridge (4°C)	Freezer (-18°C)
Fresh, just expressed	Up to 4 hours	Up to 4 days	About 6 months is best, up to 12 months is acceptable
Thawed from frozen	1–2 hours	Up to 24 hours from when fully thawed	Don't refreeze
Left over after a feed	Discard within 2 hours after your baby has finished

Source: CDC (Centers for Disease Control and Prevention, USA). These times are for healthy, full-term babies. For premature babies or babies in hospital, follow the hospital's instructions.

How to store it

Wash your hands well before expressing or handling milk.
Use breast milk storage bags or food-grade glass or plastic containers with tight-fitting lids.
Store it in small amounts, about 60–120 ml, so you don't waste milk when your baby doesn't finish.
Write on each container the date you expressed it. If your baby goes to nursery, add their name.
Put it at the back of the fridge or freezer, not in the door, where the temperature changes a lot.
When freezing, leave a little space in the container, as milk expands.
On the go, an insulated cooler bag with ice packs keeps milk safe for up to 24 hours.

How to thaw and warm it

Always use the oldest milk first.
Thaw it in the fridge overnight, under lukewarm running water, or in a bowl of lukewarm water.
Never warm it in the microwave. It heats unevenly and can burn your baby's mouth.
Milk doesn't need to be warm. Many babies drink it at room temperature or cold.
The fat separates and rises to the top. Swirl the container gently to mix it, without shaking hard.
Test the temperature with a few drops on the inside of your wrist. It should feel lukewarm, not hot.

Colour and smell of the milk

Breast milk can look white, slightly yellow, bluish or, depending on what you eat, other shades. This is normal. After freezing it sometimes smells soapy or metallic. It's usually safe, but if your baby refuses it, talk to a lactation consultant.

Track it with Ditari i Bebes

In Ditari i Bebes you log expressed milk and every bottle feed. So you know how much your baby has drunk, even when someone else feeds them.

See the app

Sources

CDC: Breast milk storage and preparation

This guide is for information only and doesn't replace advice from your doctor, midwife or lactation consultant. Every mother and every baby is different. If something worries you, talk to your doctor.