Expressing and storing breastmilk

Expressing and storing breastmilk

You can release milk by hand (manually) or with a breast pump. This is called expressing. There may be times when you need to express your breastmilk in the hospital or at home. This can happen when:

  • you need to start or maintain your milk supply
  • you miss a feeding
  • your baby needs an extra feeding (supplementation)
  • your breasts are engorged
  • you are separated from your baby
  • your baby needs to take a bottle
  • you are having trouble breastfeeding (Your baby cannot latch-on or maintain an effective latch.)
  • you have a history of low milk supply
  • you have had a breast reduction
  • your baby was born early or has a low birth weight

You can save the milk for a later feeding.

Hand expressing breastmilk

To express your breastmilk:

  • Wash your hands.
  • Help your milk let down by first massaging or stroking your breast (see photo A). Avoid sliding your hand over your breast down to the nipple. This can cause skin irritation.
  • Place your hand on your breast with your fingers one to one and a half inches behind the nipple (see photo B).
  • Push straight back into the chest wall without spreading your fingers. If your breasts are large, lift your breast and then push (see photo C). You may use two hands.
  • Gently compress (squeeze) the areola in one motion. Do not pull your nipple out.
  • Repeat in a rhythm: position fingers, push in, compress and release. Position, push in, compress and release.
  • Expressing should be comfortable.
  • When you no longer get milk, rotate your thumb and fingers.
  • Switch back and forth from breast to breast.
  • Collect the breastmilk in a clean cup, spoon or other clean container (see photo D).
Hand express

A:Position for massage.

Hand express

B:How to place your hand.

Hand express

C:Gently push straight back.

Hand express

D:Gently compress then collect the breastmilk.

All photos © Allina Health System

Pumped milk can have a soapy or metallic odor when it is refrigerated or thawed. This does not mean the milk has gone bad.

Call your lactation resource if your milk has an odor.

Expressing milk with a breast pump

Not everyone needs a breast pump. It depends on your situation and lifestyle. Wait to buy one until you determine if you need one.

Not all pumps are created equal. Breast pumps vary a lot in quality and effectiveness. Choose a high-quality pump. Your lactation resource will help you find a pump that's right for you. Call your insurance provider to see if a pump is covered by your policy.

Remember: Using a breast pump should never cause you pain. If you do have pain, stop using the pump and call your lactation resource right away.

Before you start pumping, wash your hands well. Sit comfortably and take a few slow relaxing breaths. Massage your breasts to help your milk let down. Pump your breasts according to the pump's instructions.

It is important that any part of the pump that comes in contact with the breast, milk, or collection containers be very clean. Wash them in hot, soapy water. Rinse and air dry them on a clean towel. You can also wash them in a dishwasher.

Storing breastmilk

Breastmilk can be safely kept in the refrigerator or freezer. There are different styles of containers for storing breastmilk: special plastic bags, bottles and glass containers.

Be sure to wash the milk containers in hot, soapy water. Rinse them and let them air dry. Wash your hand well before you touch your breasts and clean milk containers.

How to store fresh breastmilk

  • Write the date on the container.
  • Pour the pumped milk into the container.
  • Freshly pumped breastmilk can be kept at room temperature for up to four hours.
  • You can collect small amounts of milk during the day and keep it in the refrigerator.

How to store frozen breastmilk

  • Write the date on the container.
  • Pour the pumped milk into the container.
  • Freeze milk in two- to four-ounce portions. This is about what a newborn takes during a feeding. This portion also thaws quickly in warm water.
  • If you are using special plastic bags, fill about three-quarters full. Leave space at the top of the bag to allow the frozen milk to expand.
  • Fold the top of the plastic bag over several times and seal with freezer or masking tape, or a twist tie.
  • Put the plastic storage bags into a larger plastic bag.

How to add fresh breastmilk to frozen breastmilk

If you pump in small quantities, you can add fresh milk to frozen milk.

  • Place fresh milk in the refrigerator until cold.
  • Once fresh milk is cold, add it to the already frozen milk.

Breastmilk storage guidelines

Where to store Temperature How long to keep How to store

room temperature

  • 50 to 85 F
  • 10 to 29 C
  • Up to four hours is best, especially at higher room temperatures
  • Up to eight hours at cooler room temperatures
  • Keep containers covered and as cool as possible.

insulated cooler bag with ice pack

  • 59 F or cooler
  • 15 C or cooler

  • 24 hours
  • Make sure that an ice pack touches the milk containers at all times.
  • Limit the number of times you open the cooler bag.
  • 39 F or cooler
  • 4 C or cooler
  • Up to 72 hours (three days) is best
  • Up to eight days is OK if your refrigerator is very clean
  • Keep the milk containers in the back of the main part of the refrigerator (not in the doors). 
freezer (compartment of a refrigerator with separate doors)
  • 0 F or cooler
  • -18 C or cooler
  • Up to six months
  • Keep the milk containers in the back or the bottom of the freezer. 
upright or chest deep freeze
  • -4 F or cooler
  • -20 C or cooler
  • Up to 12 months
  • When milk is stored for longer times, the fats (lipids) will start to break down.
  • The milk is still safe, but the milk quality can be lower.

Guidelines based on the ABM Clinical Protocol #8 Human Milk Storage for Home Use for Full-Term Infants 2010.

How to warm breastmilk from the refrigerator

  • Put the container of milk in a bowl of warm tap water or warm it under warm running water.
  • Gently shake the milk.
  • Test the temperature by shaking out some milk on your wrist. It is normal for the milk to separate into a milk and a cream layer.
  • Warning: Don't bring the milk to the boiling point. Don't warm milk in the microwave. This can create "hot spots" that can burn your baby.

How to thaw frozen breastmilk

You may thaw frozen breastmilk one of two ways. For either way, be sure to use the oldest milk first.

  • Place the container in the refrigerator. Thawed milk can stay in the refrigerator for up to 24 hours.
  • Place the container in a bowl of warm tap water or warm it under warm running water.

Source: Allina Health's Patient Education, Guide for the Care of Children: Ages Birth to 5, sixth edition, ped-ah-91554
First Published: 02/01/2010
Last Reviewed: 11/16/2022