Breast Milk Storage Guide

Wondering how long expressed breast milk is safe? Pick whether it’s freshly pumped, thawed, or leftover from a feed, and where you’re keeping it — we’ll show the safe time, and an exact “use by” if you add when you expressed it.

Type of milkWhere are you storing it?

When did you express it? (optional)

Safe to use for

4 days

Add the time you expressed it to get an exact “use by”.

All the storage times at a glance

Situation	Room temp	Fridge	Freezer
Freshly expressed	4 hours	4 days	6–12 months
Thawed (was frozen)	1–2 hours	24 hours	Never refreeze
Leftover from a feed	2 hours	Not recommended	Not recommended

Label every container with the date and use the oldest milk first.
Store at the back of the fridge/freezer, not in the door, where it’s coldest.
Thaw in the fridge or under warm water — never the microwave — and swirl, don’t shake.

General guidelines only, not medical advice. Storage advice can vary (for example for premature or hospitalised babies) — follow your healthcare provider or your country’s official guidance.

How it works

Storage times depend on the milk and the temperature. Freshly expressed milk keeps about 4 hours at room temperature, up to 4 days in the fridge, and around 6 months (up to 12) in a freezer. Milk that’s already been thawed should be used within 24 hours in the fridge and never refrozen, and milk left over from a feed is best used within about 2 hours.

Add the time you expressed it and we’ll add the safe window to give you a clear “use by” moment — so you don’t have to do the math. These are widely-used general guidelines; storing milk at the back of the fridge or freezer (not the door) keeps it coldest, and labelling each container with the date helps you use the oldest first.

Frequently asked questions

How long does breast milk last in the fridge? +

Freshly expressed breast milk keeps for up to about 4 days in a fridge at around 4°C (39°F). Store it at the back, where it’s coldest, rather than in the door. If you won’t use it in that time, freeze it.

Can I refreeze thawed breast milk? +

No. Once breast milk has thawed, use it within 24 hours if it’s in the fridge (or 1–2 hours at room temperature) and never refreeze it. Refreezing isn’t considered safe.

How long can breast milk sit out at room temperature? +

Freshly expressed milk is generally fine for about 4 hours at room temperature. Milk left over from a feed (that baby has drunk from) should be used within about 2 hours, because saliva introduces bacteria.

How should I store and thaw breast milk? +

Use clean, sealed containers or bags, label them with the date, and keep them at the back of the fridge or freezer. Thaw in the fridge overnight or under warm running water — not in the microwave — and swirl (don’t shake) to mix.