Can I mix breast milk from different pumping sessions? Yes certainly you can combine breastmilk but there are a few guidelines. If you are pumping twice in a day, keep the first milk covered in the fridge. Then when you express again, you will need to use a different bottle and then chill that milk before adding it to the first milk. You should not add your warm breast milk (at
body temperature) to the chilled fridge milk. You need to cool the warm breast milk before you add it to the already chilled milk. If you are expressing over several days, we recommend that you freeze the milk in small quantities to avoid wasting it. Just make sure you cool down your freshly expressed breastmilk before you add it to the frozen stored milk. In other words, if you have 50mls pumped, cool it and then add to the frozen supply for the baby’s feed. Only
add cold milk to cold milk or cold milk to frozen milk. Because you never want to waste breast milk, you might consider freezing it in relatively small amounts for each feed. This way, if your baby doesn’t take it all, you won’t be throwing it out, plus it will be quicker to defrost and warm. Read our suggested How Much Does Baby Drink If your baby does not drink all the milk in one feed – you CANNOT reuse the milk later, you will need to discard it.
How much expressed milk will my baby need? @ How much?
Storage guidelines
HUMAN MILK STORAGE – QUICK REFERENCE CARD | ||
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
Previously frozen milk may be kept in the refrigerator for up to 24 hours after it has finished thawing. Do not refreeze. Now infants can get To warm milk
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. |
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More on Milk Storage
@
- Human Milk Storage – Quick Reference Card
- Human Milk Storage – Guidelines for Premature Infants
- Milk storage handouts for professionals
Academy of Breastfeeding Medicine Clinical Protocol #8: Human Milk Storage Information for Home Use for Full-Term Infants (March 2010)
Why Do Milk Storage Guidelines Differ? by Nancy Mohrbacher, IBCLC, FILCA
What are the LLLI guidelines for storing my pumped milk? from La Leche League International
Storing and transporting breast milk from AskDrSears.com
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
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.
Travelling with Breast Milk by Robyn Roche-Paull, BSN, RNC-MNN, IBCLC
Traveling as a Pumping Mother by Nicole Goodman
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.
What is normal?
Unusual appearances of breastmilk from the Australian Breastfeeding Association
My expressed breastmilk doesn’t smell fresh. What can I do? @KellyMom
What does breastmilk look like? by Paula Yount
Why does my breastmilk change colors? by Anne Smith, IBCLC
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)
More information @KellyMom:
- Pumping & Supply
- Feeding baby your milk (bottles & more)
- Milk handling and storage
- Employment & Breastfeeding