Medela Tips for Pumping Breastmilk – Packing, Freezing, Storing and Re-heating

Medela Tips for Pumping Breastmilk – Packing, Freezing, Storing and Re-heating

Get Started on Breastfeeding & Tips

Share this content:

Once you are accustomed to the basics of pumping breastmilk, you might want to look for new ways to make breastpumping a bigger part of your life and extend the convenience of this way of feeding your baby. Maybe you love to breastfeed and know all the benefits of breastmilk, but want to go back to work, share the night feeds, or you just want a break from breastfeeding sometimes. Or perhaps you are an exclusively breastpumping mom whose baby for one reason or another cannot feed from the breast.

Maybe you are working and pumping so that your nanny or child minder can feed your little one during the day, and you have invested in a great Medela breastpump, but now you have extra milk you don’t know what to do with it. It’s important to store your breastmilk the right way so you can preserve its nutrients and immunity-boosting benefits for your baby. Human milk actually has anti-bacterial properties that help it to stay fresh. You just have to store, freeze, and rewarm it properly.

Here are a few tips for how to pack, freeze, store and thaw breastmilk to give your baby an efficient source of nutrition and immunity, even when you’re not there to breastfeed:

Equipment You Will Need:

  • A great breastpump that fits your lifestyle.
  • A good size freezer.
  • Storage containers – you have 2 basic choices from Medela:
    • Medela Breastmilk Bottles: These are made out of BPA-free polypropylene and are safe for babies. Our breastmilk bottles are designed to store and protect your breastmilk through all the stages of refrigeration, freezing and warming. They help to maintain breastmilk’s complex life-enhancing beneficial nutritional properties.
    • Medela Breastmilk Storage Bags: If you prefer not to use a bottle for storage, you can save space in your freezer by using a bag. Medela Breastmilk storage bags take up less space than breastmilk bottles, and you can pump milk directly into the bag, preventing milk loss.



Medela offers extensive guidelines for storing breastmilk at room temperature, in the refrigerator, or in the freezer. Tips include:

  • Wash your hands before touching bottles and bags, and avoid touching the interior of bottles or caps.
  • Pump or express your breastmilk into clean bottles or bags. If using Breastmilk storage bags, always use a new bag for each pumping session.
  • To avoid waste, store milk in small portions by putting only 60 to 120 ml (two and half to four ounces) of milk in the container (that’s the amount your baby is likely to eat in a single feeding).
  • Fill the container up to ¾ only. Milk will expand when freezing.
  • Squeeze out the air at the top of the milk bag before sealing. Disposable bottle liners or plastic bags are not recommended because with these, the risk of contamination is greater.
  • Mark the collection date on the storage container.
  • Include your baby’s name on the label if your baby is in day care.



Breastmilk can be safely frozen and stored for up to 12 months, but it requires special handling:

  • Breastmilk should be stored and frozen in small amounts of 60ml to 120ml per bottle or bag. The reason for this is that it takes less time for smaller amounts to thaw, and also this is close to the typical amount that babies consume at each feeding session.
  • When freezing breastmilk, be sure to leave some space in the container for the liquid to expand – you should only fill the bottles up to ¾ full, and do not fill bags with more than 150 ml of breastmilk.
  • Cool the breastmilk before putting it in the freezer, and never re-freeze breastmilk once it has been thawed.
  • If you want to refrigerate breastmilk for several days or freeze it, it’s important to seal the bottles tightly and use solid lids.
  • Put breastmilk inside the main compartment of the refrigerator towards the back and at the bottom– do not store it in the door of the refrigerator, since the temperature there can be less consistent.

The needs of babies change over time. Therefore breastmilk is ever changing and its composition changes with the age of the baby. So it makes sense to use frozen breastmilk within 3 months in order to match the baby’s needs.


Thawing breastmilk requires careful attention and following a step-by-step process – you want to make sure the breastmilk is at the right temperature for your baby to consume:

  • Thawing with water: Place the frozen breastmilk (in its sealed container) into a bowl of cool water, or hold it under a faucet of cool running water. You can use this process to thaw the frozen milk until it is melted/in liquid state, but still cold – then simply dry off the bottle with a towel, and put the cold liquid breastmilk in the refrigerator until ready to feed your baby. (Run the breastmilk under warm water before feeding your baby – but make sure the temperature is not above 37°C).
  • TThawing breastmilk in the refrigerator: Simply put the frozen breastmilk in the refrigerator and leave it there overnight. Once it is thawed the next day, swish the container around to re-mix any fats that separated overnight during storage.
  • TOnce you have thawed the breastmilk to fridge temperature, you can feed the thawed milk to the baby immediately, or store it in the refrigerator for up to 24 hours.
  • TYou can also use thawed breastmilk away from home. If you are on vacation or bringing breastmilk with you to another location, bring a cooler full of ice packs to help keep the breastmilk cool.


Safety Tips for Thawing and Rewarming Breastmilk:

  • Never use a microwave or boiling water to thaw or warm breastmilk. The reason for this is that high temperatures will damage the breastmilk’s essential nutrients. Also, microwaved breastmilk can cause the milk to heat unevenly throughout, creating “hot spots” that are dangerous to the baby.
  • Do not let thawed breastmilk sit out at room temperature.
  • Do not refrigerate warmed breastmilk. Any milk that the baby does not consume should be discarded.

Once you get into the breastpumping flow (pun intended) you will find that having a good supply of fresh breastmilk can open up a new more relaxed lifestyle, giving you more time to work, go to school or do other activities with your baby and other children. You might even get to drink a cup of coffee when it is still hot!