Breastmilk Storage & Handling

How much? | Handling | Storage guidelines | What is normal? | Is it bad?

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How much?

How much expressed milk will my baby need? @


Reusing expressed breastmilk @

My power went out and I have breastmilk in the freezer – Help! @

Don’t Shake the Milk by Linda J. Smith, BSE, FACCE, IBCLC.  Another source also indicates that shaking has the potential to destroy the protein structure of large proteins in biologically active substances: “…many large proteins cannot be shaken to reconstitute, as shaking can destroy the protein structure” (Morrow T, Felcone LH. Defining the difference: What Makes Biologics Unique. Biotechnol Healthc. 2004;1(4):24-9). How likely is this to be an issue? We don’t know! So far there has not been research done on the bioactive properties of shaken vs. non-shaken breastmilk (fun research project – any takers?). Some feel that the forces required to change the milk are significantly more than could be provided via shaking. Others note that shear forces from shaking are not the only issue–bursting of bubbles caused by shaking may also damage cells or denature proteins. To play it safe, use the smallest amount of force needed to mix the layers, keeping in mind that the layers will mix better as the milk warms. If you do shake the milk, it might not be a problem at all–and even if it turns out that shaking makes a difference it will still be the best nutrition for your child.

Packaging and Shipping Frozen Breastmilk from Breastfeeding in Combat Boots

Using Dry Ice Safely when Traveling with Breastmilk from the Children’s Hospital of Philadelphia

Jeffery SL, Cubison TC, Greenaway C, Gilbert PM, Parkhouse N. Lesson of the week. Warming milk-a preventable cause of scalds in children. BMJ. 2000 Jan 22;320(7229):235.


Storage guidelines

Temperature Storage Time
Freshly expressed milk
Warm room 80-90°F / 27-32°C 3-4 hours
Room temperature 61-79°F / 16-26°C 4-8 hours
(ideal: 3-4 hours)
Insulated cooler / ice packs 59°F / 15°C 24 hours
Refrigerated Milk (Store at back, away from door)
Refrigerator (fresh milk) 32-39°F / 0-4°C 3-8 days
(ideal: 72 hrs)
Refrigerator (thawed milk) 32-39°F / 0-4°C 24 hours
Frozen Milk (Do not refreeze! Store at back, away from door/sides)
Freezer compartment inside refrigerator (older-style) Varies 2 weeks
Self-contained freezer unit of a refrigerator/freezer <39°F / <4°C 6 months
Separate deep freeze 0°F / -18°C 12 months
(ideal: 6 months)
These guidelines are for milk expressed for a full-term healthy baby.  If baby is seriously ill and/or hospitalized, discuss storage guidelines with baby’s doctor.
To avoid waste and for easier thawing & warming, store milk in 1-4 ounce portions. Date milk before storing. Milk from different pumping sessions/days may be combined in one container – use the date of the first milk expressed. Avoid adding warm milk to a container of previously refrigerated or frozen milk – cool the new milk before combining. Breastmilk is not spoiled unless it smells really bad or tastes sour.To thaw milk

  • Thaw slowly in the refrigerator (this takes about 12 hours – try putting it in the fridge the night before you need it). Avoid letting milk sit out at room temperature to thaw.
  • For quicker thawing, hold container under running water – start cool and gradually increase temperature.

Previously frozen milk may be kept in the refrigerator for up to 24 hours after it has finished thawing. Do not refreeze.

To warm milk

  • Heat water in a cup or other small container, then place frozen milk in the water to warm; or
  • Use a bottle warmer.
  • NEVER microwave human milk or heat it directly on the stove.

The cream will rise to the top of the milk during storage. Gently swirl milk (do not shake) to mix before checking temperature and offering to baby.

If baby does not finish milk at one feeding, it is probably safe to refrigerate and offer within 1-2 hours before it is discarded.

Want to print the above information? Go to PDF Quick Reference Card


Academy of Breastfeeding Medicine Clinical Protocol #8: Human Milk Storage Information for Home Use for Full-Term Infants (March 2010)

What are the LLLI guidelines for storing my pumped milk?

Traveling as a Pumping Mother by Nicole Goodman

Storing and transporting breast milk from

Common Concerns When Storing Human Milk by Cindy Scott Duke, from New Beginnings, Vol. 15 No. 4, July – August 1998, p. 109

Freezing Your Breastmilk by Paula Yount

Rechtman DJ, Lee ML, Berg H. Effect of Environmental conditions on Unpasteurized Donor Human Milk. Breastfeed Med. 2006 Spring;1(1):24-6.

Hamosh M, Ellis LA, Pollock DR, Henderson TR, Hamosh P. Breastfeeding and the working mother: effect of time and temperature of short-term storage on proteolysis, lipolysis, and bacterial growth in milk. Pediatrics. 1996 Apr;97(4):492-8.

More journal articles on milk storage

What is normal?

What does breastmilk look like? by Paula Yount

Common Concerns When Storing Human Milk by Cindy Scott Duke, from New Beginnings, Vol. 15 No. 4, July – August 1998, p. 109 (normal taste & appearance)

Storage and Handling of Breastmilk by Becky Flora, BS, IBCLC (normal appearance)

Is it bad?

My expressed breastmilk doesn’t smell fresh. What can I do? @

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