Breastmilk Storage + Handling

Primarily based on CDC guidelines but with some real world guidance.

☆ One of the most important keys to preventing bacterial growth and infection is proper hand & bottle hygiene! This is especially critical for babies 8 weeks and under, or immunocompromised for any reason - born premature, certain medical conditions, etc. Infection or fever at this age is particularly dangerous.

• Expressed colostrum

  Prenatal: freeze right away
  Add to it as needed or freeze each session separately and combine when thawed if needed.

  Postpartum: feed within 2-3 hours or store in the fridge for up to 4 days

• Freshly expressed breastmilk - room temp

  After Pumping: up to 4 hours per CDC, but likely safe up to about 6 hours

  Once baby’s mouth has touched the bottle, try to use within about 2 hours - likely safe to use for the next feeding (~3 hours).

• Freshly expressed breastmilk - refrigerator

  Up to 4 days per CDC, likely safe until about 6 days.

  Store in the coldest part of your fridge - against the wall of the fridge, away from the door, never on the shelves of the door

• Freshly express breastmilk - freezer

  4-6+ months in a conventional freezer
  12+ months in a deep freezer

  In a conventional freezer, milk is generally still safe to feed after 6 months but may start to taste differently. You can mix it with fresh milk/formula, put a drop of vanilla extract into it, or use it for making purees/oatmeal.

  Be mindful of freezer location - against the wall of the freezer, away from the door, never on the shelves of the door.

• Thawing frozen breastmilk

  Planning Ahead: Put the milk in the fridge to defrost the day before you’ll need it. A 4 oz bag will likely take 12-18 hours to defrost completely.

  Quick Defrost: Under running cool-to-lukewarm water for 5-10 minutes or sitting in a bowl of cool water for 15-20 minutes. You can also put it in a bottle warmer with some ice chips still present.

  Use within 24 hours. The clock starts when your milk is considered fully defrosted - aka when there are NO MORE ice chips at all in the milk.

  Never re-freeze once fully defrosted. However, if there are still ice chips present, it is still considered cold enough to safely go back in the freezer if need be. This also means if someone leaves the freezer door open overnight, while you may need to throw out the ice cream but (as long as there are any ice crystal in the container) DO NOT toss it!

• Mixing breastmilk + formula

  Always make powdered formula per package directions first and then add breastmilk.

  For combo fed babies, I really recommend mixing breastmilk and formula per feeding whenever feasible. Ex: You have 4 oz of breastmilk available, give two bottles of 1/2 BM + 1/2 F instead of one full BM and one full formula. This will aid in their ability to digest their milk more easily compared to having some fully breastmilk and some fully formula bottles.

  The number one reason many people hold off on this is the risk that if your baby doesn’t finish the bottle, some breastmilk may go down the drain if not finished within 2 hours. Totally up to you when & if you’re ready for mixing!

  That being said, it’s 100% safe to give full formula bottles if need be or preferred by your family.

• Traveling with breastmilk

  Per CDC, store breastmilk in an insulated bag with ice packs for up to 24 hours.

  F+F Tips/Recommendations:

  • My favorite cooler for this is the Packit snack size or lunch bag. Insulated bag + ice pack all in one.

  • Another great option is the Ceres Chill, which has a compartment for ice which means you can swap out the ice as much as you need/are able too. You can even pump into it and feed from it with the right parts.

  Flying with Breastmilk

  • A great resource for packaging &/or shipping your milk: Milk Stork. Some companies even pay for this as an employee benefit.

  • Your milk can be stored in bottles or bags, in volumes greater than 3.4oz. This also applies to whatever cooler/ice packs you need to safely store your milk.

  • There is not a limit on the quantity of breastmilk or formula you can bring on a flight.

  • Though the CDC & TSA guidelines are pretty clear, I really recommend you understand them (maybe even print them out?) because I have heard nightmare stories about TSA agents.

  • Traveling internationally can be tricky since each country may have their own regulations but here is an article with a wide variety of policies from different countries.

• "Expired" milk

  Based on whatever criteria you feel comfortable with, if you do have milk that would be thrown away - Instead, it can be saved for 1-2 weeks and used for their skin - for ex in bath water or as a lotion!

• The "Fridge Hack"

  If you’ve spent any manner of time browsing baby or breastfeeding videos on Instagram or TikTok, you might’ve heard about the “fridge hack” to save you time between pumping sessions.

  What is it? Storing your pump parts in the fridge/freezer in between pumping sessions.

  Why would someone do it? Primarily to save time and be able to pump more quickly without prepping and washing your parts. The essential idea behind it is that refrigeration would stunt bacterial growth in the pump parts (just as it will for the milk you regularly store in the fridge for up to 4 days).

  Is it right for me? I want to be clear that this is different from what the CDC recommends, which is to wash parts after each use. So it's not for anyone to decide but you. But families who have a baby less than 8 weeks, born prematurely, being cared for in NICU and/or immunocompromised should take particular caution when it comes to infection risk and may want to be more vigilant about cleaning parts with each use.

  How would I do it smartly? Wash and scrub pump parts (and if desired, sterilize) at least every 24 hours. Wipe off the exposed edges of your flanges with a tissue or paper towel before storing. Store them on the inside of your refrigerator (not the door) in a sealed container (zip-loc bag or tupperware container).

Printable version of this info!