May 23

Donate Quality Milk

Most donor milk is used to feed tiny sick babies so using good technique to have the best quality milk is important.

Keep It Clean

Milk should be free from too many bacteria.

Using good clean technique when you pump to donate is important.

  • Wash your hands before pumping (you do not need to wash your breasts).
  • Use new or sterile breastmilk bags or bottles.
  • Be careful not to touch the inside of the bag, bottle or cap as you fill them.
  • Milk to be donated should be frozen soon after pumping and not more than 4 days after pumping.
  • Keep your equipment very clean- sterilize your pump kit every day, and the tubing once a week. Micro-steam bags, bottle sterilizer or stovetop boiling water bath are all effective.*
  • Be sure to let your pump kit dry out well between uses, bacteria love moist environments.

*Click here for the CDC guidelines for keeping your pump equipment clean.

Keep It Contained

Milk can be stored in bottles or bags.

You may be using standard breastmilk storage bags and those are the easiest for the milk bank to handle.

Mothers of NICU babies often have many small bottles of milk and that is fine too.

If you know you are going to donate, the bags are best and cheapest method and take up less space.

Many mothers who pump to donate freeze the milk flat to help the storage room problem.

Keep It Labeled

Label your milk well.

Write your name, your Donor ID if you have one, the date you pumped and the quantity of milk (a guesstimate is fine).

If you have hospital labels on the milk that is great, just make sure they stick well.

Keep It Frozen

Milk must be frozen solid in a standard or deep freezer, and be less than 6 months old to donate.

A deep freezer keeps milk super cold and is best.

A standard freezer is fine, but put the milk in the far back and not in the door to keep the temperature low.

Check your freezer temperature, it should be under 0 degrees Fahrenheit (-18° C), if your ice cream is very hard that’s a good indication that its cold enough.

If your breastmilk has thawed by accident or due to a freezer mishap, it may still be accepted for research donation, but it shouldn’t be fed to babies. Call us at 858-249-1717 to discuss before you throw that milk out!

Keep The Quality

On the day you bring your milk to donate be sure to pack it well in a cooler bag or chest.

If the milk is thawing it might not be accepted, so best to pack it and drive right over to donate.

If you have empty space in the cooler, crumple up newspaper and fill the chest/cooler rather than adding wet ice, because regular wet ice will actually melt your milk.

Dry ice is a good option to keep milk very cold if you can’t come right over to donate.


Lisa Stellwagen MD, FAAP  Professor of Clinical Pediatrics at UC San Diego Health