Appointments: 913-888-4567
Billing: 913-825-0923
Breastfeeding > Breastfeeding: Storage of Breast Milk

Breastfeeding: Storage of Breast Milk

When you collect and store breast milk properly, you will help your baby receive the benefits of breast milk. Follow these guidelines so your breast milk will keep most of its nutrients and disease-fighting ability.

General guidelines

Wash your hands with soap and water before pumping.
Wash all containers and breast cups with soap and hot water before each use. Avoid touching the inside of the containers after they are clean.

Breast milk storage

  • When you start pumping, you may only get small amounts of breast milk. With time your supply (the amount of milk) should increase with each pumping. If you mix milk from different pumpings, be sure they are both refrigerated to a cold temperature (never mix refrigerated milk with freshly pumped warm milk before storing). If you are double pumping, you may combine the breast milk from each breast into one container. If you pump more than your baby takes at one feeding, divide the breast milk into “feeding size” containers.
  • Milk may be frozen in milk bags or bottles. Be sure to leave room in the bottle for the breast milk to expand as it freezes. You are strongly encouraged to not use polyethylene bags to store or freeze breast milk.
  • Label each bottle or bag with your baby’s name and date, so you can use the oldest milk first, and never use milk past its expiration date (see below).
  • Refrigerate or freeze the breast milk immediately:
    • Refrigerator: The breast milk should be frozen or used within 96 hours (4 days).
    • Freezer: (standard) Breast milk may be stored for 3 to 6 months.
    • Deep Freezer: Breast milk may be stored for 6 months to 1 year.
  • When you store the breast milk in a freezer, place it on a shelf near the back. This will avoid temperature changes from the door being opened or from the defrost element, which is usually on the bottom of the freezer.
  • Smelling milk before feeding it will let you know if it is rancid. Do not feed milk that has a funny odor.

Transporting breast milk

  • Frozen breast milk should stay frozen during transport. This reduces the risk of warming the breast milk, which could encourage bacterial growth.
  • All breast milk should be packed securely in a cooler for transport. Ways you can pack the cooler securely are:
    • Use towel(s) for packing.
    • Use frozen blue ice.
    • Use soft packs of ice (blue, ice bricks).
  • If you are pumping away from home, keep the breast milk in a cooler with frozen blue ice or in a refrigerator until you get home. Be sure to place the breast milk in a freezer as soon as you can.

Thawing breast milk

  • The way the breast milk looks may change after it has been stored. The color may change and parts of the breast milk may separate.
  • To thaw frozen breast milk:
    • Place in the refrigerator overnight: use within 24 hours after thawing.
    • Place in a cup of hot (not boiling) water. Make sure that the water does not get into the breast milk as it thaws.
  • If breast milk thaws during transport, but remains chilled in a cooler, thawed breast milk should be used within 24 hours.
  • Use the oldest frozen milk first.
  • Do not thaw or heat breast milk in a microwave oven.
This page was adapted from the Children's Mercy Care Cards with help from the lactation nurses at Overland Park Regional Medical Center.

Find health information quickly in our parent toolkit.

Illnesses & Symptoms