Whether out of necessity for return to work or desire for flexibility with feeds,  most parents at some point will express their milk and introduce bottles.

It’s important to correctly store pumped milk to protect its biological properties and reduce the risk of contamination. Human milk is a living, dynamic food, even when not available directly at the breast. It is the gold standard for infant nutrition.

Prior to expressing milk by hand, manual pump or double electric pump, parents should wash their hands thoroughly with soap and water. The pump itself should be clean. Milk should be collected in clean containers that were washed in hot, soapy water, thoroughly rinsed and air dried, or dried with a paper towel. Milk can be expressed/stored in glass bottles, bottles that are BPA free or plastic storage bags specifically designed for human milk.

Guidelines below are based on healthy, full-term infants. Milk storage guidelines differ for infants that are are preterm, ill or in the NICU.

• All milk should be dated before storing. Be mindful of expiration dates. Use the oldest fresh or frozen milk first. Avoid accumulating a large freezer stash.
• If freezing, leave about 1 inch at the top to allow for expansion. To take up less space, lay milk flat in human milk storage bags and stack on top of each other. The bags can be contained in a large, plastic freezer bag, which adds an extra layer of protection.
• Thaw milk overnight in refrigerator or by placing in a bowl of lukewarm water. Never refreeze thawed milk.
• To avoid waste and for easier thawing, store milk in portions of 1-4 oz. (30-120 ml). to previously expressed milk.

For current human milk storage guidelines, per the CDC, check here https://www.cdc.gov/breastfeeding/pdf/humanmilk-en-4×6-508.pdf