Expressing — by hand or with a pump — is a useful tool rather than a milestone. It lets someone else give a feed, builds a small stash for a night off or going back to work, eases uncomfortably full breasts, and keeps your supply going if you and your baby are apart. One thing to hold onto from the start: what you can pump is not a measure of your supply — babies are far more efficient than pumps. Here’s why and when to express, how to do it, and the part that really matters — storing milk safely.

Why and when to express

A few common reasons:

There’s no need to pump in the early days unless there’s a reason — in the first weeks, feeding directly is usually all that’s needed.

Hand expressing and pumps

Hand expressing needs no kit and is especially handy for the early drops of colostrum: cup your breast, then compress and release in a steady rhythm, moving around. Pumps come as manual, or single or double electric — a double pump is quicker and worth it if you’ll express regularly.

Whichever you use, it works best when you’re warm, comfortable, and relaxed; a little breast massage, or even just thinking about your baby, helps your milk let down. Use a flange (the funnel) that fits, keep the suction comfortable — stronger isn’t better — and express for about 15–20 minutes or until the flow slows. Milk supply is often highest in the morning, a good time to catch a little extra.

Storing milk safely

This is the part to get right. Store milk in clean, sterilised bottles or special bags, in small amounts so none is wasted, and label each with the date:

WhereRoughly how long
Room temperature (a cool room)up to ~4 hours
Fridge, at the back (~4°C, not the door)up to ~3 days
Freezerup to ~6 months
Thawed in the fridgewithin 24 hours — never refreeze

Cool fresh milk in the fridge before adding it to already-frozen milk. Thaw frozen milk in the fridge overnight or under warm running water, never in the microwave (hot spots, and it damages the milk). Exact times vary by country and source, so check your local guidance too.

Giving expressed milk

Warm it gently in warm water or a bottle warmer, test it on your inner wrist, and give it by paced bottle feeding with a slow-flow teat. If your baby is also breastfeeding, paced feeding and a slow teat help protect the latch and let you mix the two freely. A little separation into layers is normal — swirl gently to mix rather than shaking.

Keeping it sustainable

Expressing on top of feeding is genuinely extra work, so let it serve a purpose rather than become a chore. Pump to a reason, not a number on a chart, clean your kit between uses, and remember a small stash goes a long way. If keeping a stash starts to stress you more than it helps, it’s fine to let it go.

The short version

Expressing is the bridge between breast and bottle — a way to share feeds without giving up breastfeeding. Nail the safe-storage habits, never judge your supply by what’s in the bottle, and warm and feed gently. And because expressed bottles are easy to measure, they’re easy to share and track between two parents — who gave which bottle, and when.

This is general information, not medical advice. Storage times and expressing guidance vary by country and for premature or unwell babies — follow the advice of your own midwife, health visitor, or lactation consultant, and your local storage guidelines.