One of the beautiful things about breastfeeding is that there are no worries about cleaning containers, refrigeration or expiration dates! Even so, many moms find it necessary or convenient to express milk for their babies when they’re away. In those situations, it’s important to know how to properly store milk so it stays fresh for baby.

Most of us are used to storing milk that has been pasteurized. Pasteurization is a method of heat-treating the milk so that harmful bacteria are killed. Unfortunately, all of the beneficial cells are killed as well. Because of this, we have learned to always keep milk and other dairy products refrigerated so that it won’t spoil.

Your freshly pumped milk, however, is dense with live cells—cells that kill nasty germs and keep the milk safe for your baby. Freezing the milk kills many of those beneficial cells. Previously frozen milk is, therefore, less stable than fresh milk. Whenever possible, feed your baby fresh milk, saving the frozen milk for emergencies.

Simple rules for milk storage:

Room temperature: 3-4 hours or until the next feeding. (Research indicates that milk can be safely stored up to 10 hours at room temperature—depending on the temperature of the room.)

Refrigerator: 5 days (Many sources quote 8 days, but that research was conducted under laboratory conditions not typical in a home situation)

Freezer: 3-4 months (varies according to temperature, frequency of opening freezer and location in freezer.)

Deep Freeze: 6 months or longer. (varies according to frequency of opening freezer)

Written by Renee Beebe, M.Ed., IBCLC. Renee is a lactation consultant in private practice in Seattle, Washington. She is available for home/hospital visits and phone consultations. Renee can be reached at www.second9months.com