How to express your breast milk

From what kit you’ll need to when’s best to start, check our tips on expressing & storing your milk

Expressing milk means your baby can still have all the benefits of breast milk, even when you’re not there! Just follow our handy hints and expert advice on how to help express.

Why should I express my breast milk?

Many women choose not to – and it’s entirely up to you – but expressing can have lots of benefits, including:

It can give your partner or anyone else the chance to feed the baby

They’ve done the nappy changing and pram pushing, but it’s lovely when your partner can take their turn feeding too.

It can give you more sleep

Enough said! "Get your partner to do the first feed when your baby wakes at night while you catch up on your sleep," says Boots Parenting Club midwife Emma Mills.

It gives you a break – and the chance to leave the house alone!

Whether it’s to have a haircut, or just post a letter, it’s so good to have a break from those first intense weeks – even just for an hour.

It can help relieve sore, engorged breasts

In the early days your baby’s feeding routine can sometimes be erratic, and they may not be sucking well. This means your breasts could feel uncomfortably full. Expressing a little can reduce that feeling of engorgement.

To get your baby used to feeding from a bottle
"I always recommend that babies are given the occasional bottle of expressed breast milk after about six weeks," says Boots Parenting Club breastfeeding expert Clare Byam-Cook*. "Many mothers choose not to, but they do often find that their baby finds it difficult to accept a bottle at a later date."

If you need to return to work – or you’re going to be away

It means your baby can still be fed your breastmilk, even if someone else is looking after them. It’s worth having some ready just in case – you never know when you might be called away, or you might get poorly and need a break from feeding.

You can have a night out!

Once you’ve got the hang of expressing and your partner can successfully bottle feed, you can enjoy an evening out with friends. Whoop! It’s advisable to only have the occasional drink, but if you do have a glass of wine, you’ll need to wait two to three hours before you feed your baby. Or, if you need to express as you’re uncomfortable, discard that milk.

*Clare Byam-Cook is the author of What to expect when you’re breastfeeding… and what if you can’t?

When can I start expressing milk?

"Don’t feel as though you have to start expressing immediately," says Emma. "Wait until breastfeeding is well established. It’s much better to let your baby get used to that before introducing changes into your routine." It can take four to six weeks to hit your stride with breastfeeding.

How do I express my breast milk?

You can express breast milk by hand or with a breast pump. Some mums find it easier to express milk by hand in the first few days, which allows you to encourage milk to flow from a particular part of the breast, while most pumps work by creating a vacuum once the funnel has been placed over the nipple. Always make sure the pump and container are clean and sterilized before use.

Expressing with a manual (hand-operated) pump

These are cheaper, less noisy and more portable if you want to take one on a night out, for example.

Expressing with an electric pump

This is the most popular choice as electric pumps tend to be more efficient than manual varieties – they also have speed settings and are less tiring to use. Electric pumps can either be charged or are battery-operated, so you can take them out with you, too. You can buy double electric pumps so you can express from both breasts at once.

What kit do I need for expressing?

As well as a breast pump, you’ll need a sterilizer, a set of bottles with teats, and storage bags or other suitable containers in which to keep your expressed milk.


When expressing, everything that meets the breast milk should be sterilized, including all the plastic breast pump attachments and all bottles, stoppers and teats. You can boil everything for 10 minutes, but many mums find it far more convenient to invest in a sterilizer. You will need to continue sterilizing until your baby is at least 12 months old.

Baby bottles and teats

If your baby has never had a bottle before, choose a teat that mimics the shape of your breast – this helps to encourage baby’s latch-on skills, even with a bottle. Ask your pharmacist or health visitor or speak to other mums for recommendations.

Breast milk storage bags or pots

Pre-sterilized for maximum hygiene, storage bags are ideal for storing milk in the fridge or freezer. Look out for double-walled ones with handy zip closures as they’re less likely to leak. Specialist re-usable plastic pots need to be sterilized but are cheaper and more eco-friendly.

How much milk should I express?

The more you express, the more your breasts will produce – that’s the deal. So, it really depends on if you want to regularly give your baby a bottle, or just keep some breast milk in the freezer for special occasions.

At first, you’ll probably only be able to pump small amounts, but this will usually increase with time. Before you start expressing, it’s a good idea to gently massage the breast to stimulate the milk. Make sure you’re comfortable and relaxed, and, "it may sound strange but looking at a photo of your baby can help stimulate your milk," says Emma.

When should I express my milk?

Emma recommends expressing in the morning, when you will usually produce more milk. Most women find it best to give their baby their morning feed and then express from both breasts, but it can be done at any time of the day (or night) – whatever suits your routine.

How do I store my expressed breast milk?

If you’re planning on using your expressed breast milk within five days, it can be stored in the fridge at up to 4˚C. Any longer, and you’ll need to freeze it – up to two weeks if it’s in an ice compartment in a fridge or up to six months if it’s in a freezer. Make sure you label your storage bags/pots with the date the milk was expressed, so you use the oldest first. To defrost, thaw slowly in the fridge or, if you’re in a hurry, you can defrost in a jug of hot water. You can feed your baby expressed milk straight from the fridge if they are happy to drink it cold.