Skip to main content

Search
Wellness Topics for Infants 0-2 Years

Breastfeeding FAQs: Safely Storing Breast Milk

|

Whether you're a new mom or a seasoned parenting pro, breastfeeding often comes with its fair share of questions. Here are answers to some common inquiries that mothers — new and veteran — may have.

Your Questions Answered
Getting Started
How Much and How Often
Sleep - Yours and Your Baby's
Your Eating and Drinking Habits
Pain and Discomfort
Out and About
Pumping
Safely Storing Breast Milk
Supply and Demand
Solids and Supplementing
Some Common Concerns

How do I store my breast milk?

You can freeze and/or refrigerate your pumped (or expressed) breast milk. You should store it in clean bottles with screw caps, hard plastic cups that have tight caps, or nursing bags (pre-sterilized bags meant for breast milk). It's helpful to put a label on each with your baby's name and the date indicating when the milk was pumped. You can add fresh cooled milk to milk that is already frozen, but add no more than is already in the container. For example, if you have 2 ounces of frozen milk, then you can add up to 2 more ounces of cooled milk.

How long, exactly, can I store my breast milk?

For healthy full-term infants:

  • You can store it at room temperature:

    • for 4 to 10 hours (at no warmer than 77ºF, or 25ºC)
  • You can store it in the refrigerator:

    • for up to 8 days at 32º-39ºF (0º-3.9ºC)
  • You can store it in the freezer (be sure to leave about an inch of space at the top of the container or bottle to allow for expansion of the milk when it freezes):

    • for up to 2 weeks in a freezer compartment located inside the refrigerator
    • for 6 to 12 months in a freezer that's self-contained and connected on top of or on the side of the refrigerator and is kept at 0ºF (-18ºC). Store the milk in the back of the freezer, not in the door) or in a deep freezer that's always 4ºF (-20ºC)

To thaw frozen milk, you can move it to the refrigerator (it takes 24 hours to thaw), then warm by running warm water over the bag or bottle of milk and use it within the next 24 hours. If you need it immediately, then remove it from the freezer and run warm water over it until it's at room temperature. Do not refreeze it.

Once your baby has started to drink from the bottle, you should use it within 1 hour. If the baby doesn't finish the bottle, you can put it back in the refrigerator, then warm it and use it at the next feeding.

You may find that different resources provide different variations on the amount of time you can store breast milk at room temperature, in the refrigerator, and in the freezer. Talk to your doctor if you have any concerns or questions.

How much of my milk should I store in the freezer?

Although some women may choose to pump large volumes to be frozen, it's a good idea to actually store the breast milk in 2 to 4 ounce (59.1 to 118.2 milliliters) portions so as not to waste any. Label the bottles, cups, or bags with the date and your baby's name, then freeze them.

You could also pour the milk into ice cube trays that have been thoroughly cleaned in hot water, let them freeze until hard, store them in freezer bags, then count up the amount of cubes needed to make a full bottle.

My frozen breast milk changed color. Is this OK?

Breast milk that's been frozen or refrigerated may look a little different from fresh breast milk, but that doesn't mean it's gone bad. It's normal for early breast milk to look kind of orange and the mature milk to look slightly blue, yellow, or brown when refrigerated or frozen. And it may separate into a creamy looking layer and a lighter, more milk-like layer.

How do I clean bottles and pump parts?

Prior to the first use, you'll need to wash and then sterilize the nipples, bottles, and washable breast pump supplies (for example, the breast shields and any other part that touches your breasts or your milk) by boiling them for 5 to 10 minutes. Check the manufacturer's recommendations for the length of time to boil the parts.

You also can sterilize the parts with a countertop or microwaveable sterilizer, but boiling works just as well and costs nothing. Thereafter, you'll need to wash the pump supplies in hot, soapy water (or run them through the dishwasher) after every use.

Bottles and nipples need to be washed and sterilized for each use for the first 3 months of the baby’s life because they can transmit bacteria if they aren't cleaned properly.

Is it safe to microwave my baby's bottles?

The microwave can create dangerous "hot spots" in bottles of formula or breast milk, so you should never microwave them. Instead, you can run the bottle or freezer bag under warm water for a little bit, swirl the bag or bottle around in a bowl of warm water, or thaw the milk in the refrigerator.

You also can put your baby's bottles in a pan of warm water (away from the heat of the stove) and then test the temperature by squirting a drop or two on the inside of your wrist before feeding your baby. And bottle warmers are available for use at home or in the car.

Reviewed by: Joseph DiSanto, MD, and Karin Y. DiSanto, IBCLC
Date reviewed: January 2012

License

Note: All information is for educational purposes only. For specific medical advice, diagnoses and treatment, consult your doctor.

© 1995–2014 The Nemours Foundation/KidsHealth. All rights reserved.

Should your child see a doctor?

Find out by selecting your child’s symptom or health condition in the list below:

Summer 2014: Good Growing Newsletter

In This Issue

  • Understanding the Power and Influence of Role Models
  • Legal Marijuana Means Greater Poisoning Risks for Children
  • Why Choose Pediatric Emergency Care?

Download Summer 2014 (PDF)

Videos

Miracle Makers 2014 3:07:00Expand
6.6.14

The 30th annual Miracle Makers fundraising special aired on KOMO 4 TV on June 6, 2014. The special takes us on a journey through the hopes, fears, victories and challenges facing patients at Seattle Children's. Cosponsored by Costco Wholesale and KOMO 4. 

Play Video
Overcoming the Odds: A KING 5 TV Children's HealthLink Special 0:44:45Expand
12.30.13

In the spirit of the holidays, patients, parents and doctors share inspirational stories of healing and hope. From surviving heart failure and a near-death drowning to battling a flesh-eating disease, witness how the impossible became possible thanks to the care patients received at Seattle Children's Hospital.

Play Video
Miracle Season 2013 0:57:06Expand
12.11.13

Miracle Season, hosted by Steve Pool and Molly Shen, aired Dec. 8, 2013, on KOMO 4 TV. The annual holiday special celebrates the remarkable lives of Seattle Children's patients.

Play Video