Storing Breast Milk

Storing Breast Milk

Topic Overview

Because what is in your breast milk changes as your baby
develops, it is best to use milk as soon as possible after pumping or
expressing it. Also, the antioxidant and other protective properties are most
important and beneficial to your baby when breast milk is fresh. The protective
components of breast milk decrease with refrigeration and freezing. But stored breast milk is the next best thing to fresh
breast milk as a complete and nutritious food source for your baby. Stored
breast milk is still better for your baby than formula.

milk can be stored and then used in the following ways:footnote 1

  • Kept at room temperature [60°F (16°C)] to [85°F (29°C)] for 3 to 4 hours. If the milk was collected under clean conditions, such as properly washed hands and properly cleaned pump parts and containers, milk may be kept at room temperature for 6 to 8 hours.
  • Kept fresh in a cooler with blue ice [59°F (15°C)] for 24 hours
  • Stored fresh in the refrigerator [39°F (4°C)] for up to 72 hours. If the milk was collected under clean conditions, it may be stored for 5 to 8 days.
  • Kept in a
    refrigerator freezer [4°F (-15.6°C)] for up to 6 months

Safe storage tips

Follow these tips when you prepare breast milk for storage.

  • Be sure to wash your hands before pumping or handling milk that will be stored.
  • Storage containers should be clean and dry. They do not need to be sterile. Wash them in hot soapy water or in the dishwasher.
  • Plastic bottle liners or small ziplock bags can be used for storage, held
    upright in cups. Be sure the bags are sturdy and stored in a place where they will not get punctured or damaged.
  • If you plan to freeze the milk, allow a little space at the top of the bag—the milk will expand when it freezes. It's also important to put the date the milk was pumped on the outside of the bag. The date will help you know which milk to use first and when to get rid of milk you didn't use.
  • Milk from both breasts expressed during the same session can
    be combined in one container. It is best to use a container that holds enough
    milk for one feeding. You are less likely to have to discard unused milk.
  • For the most consistent temperature control, store milk at the back of the refrigerator or freezer
  • When thawing or warming
    breast milk, run warm water over the storage container (which may be a bottle
    or a plastic bag) until the milk becomes slushy. You can then heat the
    container gently in a pot of warm water on the stove until the milk is slightly
    warm to the touch.
  • Frozen breast milk will separate because the fat floats to
    the top. This separation is normal and does not mean that the milk has spoiled
    or is otherwise unusable. After thawing breast milk, shake the container gently
    and the fat will redistribute evenly.

Do not:

  • Refreeze thawed milk.
  • Use thawed
    (and then refrigerated) breast milk after 24 hours.
  • Use a microwave
    oven for warming milk. Microwaves heat unevenly, creating hot spots that can
    burn your baby's mouth and throat.

There is very little research about how safe it is to refrigerate and reuse breast milk left over from a previous feeding. But many experts say it is best to throw away any breast milk left in the bottle after a feeding.

Other Places To Get Help


U.S. Department of Health and Human Services: Women's Health

La Leche League International



  1. Academy of Breastfeeding Medicine (2010). Human Milk Storage Information for Home Use for Healthy Full-Term Infants. New Rochelle, NY: Academy of Breastfeeding Medicine.


ByHealthwise StaffPrimary Medical Reviewer Sarah Marshall, MD - Family Medicine Kathleen Romito, MD - Family Medicine Adam Husney, MD - Family Medicine Specialist Medical Reviewer Kirtly Jones, MD - Obstetrics and Gynecology

Current as ofNovember 21, 2017

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