Why Do Milk Storage Guidelines Differ?

Reading different milk storage guidelines from different sources can be crazy making! Which guidelines are right? Why don't the experts agree? What do you really need to know?

The good news is that there are logical explanations for these differences. And once you know them, you can store and use your milk with confidence.

 Ideal Versus Okay

In the guidelines provided at the end of this post, some storage times for refrigerated and frozen milk are labeled “Okay” while others are labeled “Ideal.” Within the “Okay” times, expressed milk should not spoil. Between "Ideal" and "Okay," the milk is still good, but more vitamins, antioxidants, and other factors are lost. Some health organizations, like the Academy of Breastfeeding Medicine, recommend the shorter "Ideal" times because they prefer you use your milk before this loss occurs. 

It is always better to use your milk sooner rather than later, but your milk should not spoil within the "Okay" time frames. Milk found in the back of the fridge after 8 days will still be far better for your baby than formula. 

What Temperature Is Your Room?

Some milk storage guidelines also vary because they define room temperature differently. If you live in a tropical or subtropical climate, the higher room-temperature range in the guidelines below may better fit your reality. In the temperate zones, the lower range may better fit yours, at least during colder seasons.

Previously Frozen or Not?

Storage times for fresh and refrigerated milk are longer than for previously frozen milk. Freezing kills antibodies, which protect milk from spoilage. When the milk's live cells are dead, it spoils faster. When in doubt, smell or taste it. Spoiled milk smells spoiled.

Your Situation Makes a Difference

If you’re still in doubt about which guidelines to follow and how best to store your milk, ask yourself the following questions.

Is your baby healthy?  These guidelines are intended for full-term, healthy babies at home. If your baby is hospitalized, your hospital’s milk storage guidelines are likely shorter than these. Preterm and sick babies are more vulnerable to illness, so pumping and storing recommendations may be stricter.

How much expressed milk does your baby get?  If your baby gets most of her milk directly from your breasts, you don’t need to worry about whether the small amount of expressed milk she gets is fresh, refrigerated, or previously frozen. If a large percentage of your baby’s milk intake is pumped milk, consider your choices more carefully. Freezing kills antibodies, so rather than freezing all of your pumped milk, feed as much fresh or refrigerated milk as possible. But even without the antibodies, frozen milk is still a far healthier choice than formula.

Milk Storage Times for Full-term Healthy Babies at Home

Room Temperature (66°F-72°F/19°C-22°C)

• Fresh, never frozen: 6-10 hr

• Frozen then thawed: 4 hr

• Frozen then thawed, warmed but not fed: Until feeding ends

• Frozen then thawed, warmed and fed: Until feeding ends

Room Temperature (73°F–77°F/23°C–25°C)

• Fresh, never frozen: 4 hr

• Frozen then thawed: 4 hr

• Frozen and thawed, warmed but not fed: Until feeding ends

• Frozen then thawed, warmed and fed: Until feeding ends

Insulated Cooler with Ice Packs

• Fresh, never frozen: 24 hr

• Frozen, thawed: Do not store

• Frozen then thawed, warmed but not fed: Do not store

• Frozen then thawed, warmed and fed: Do not store

Refrigerator (39°F/4°C)

• Fresh, never frozen: Ideal: 72 hr, Okay: 8 days

• Frozen then thawed: 24 hr

• Frozen then thawed, warmed but not fed: 4 hr

• Frozen then thawed, warmed and fed: Discard

Refrigerator Freezer (variable 0°F/-18°C)

• Fresh, never frozen: 3-4 mo. 

• Frozen then thawed: Do not refreeze

• Frozen then thawed, warmed but not fed: Do not refreeze

• Frozen then thawed, warmed and fed: Discard

Separate Deep Freeze (0°F/-18°C)

• Fresh, never frozen: Ideal: 6 mo, Okay: 12 mo. 

• Frozen then thawed: Do not refreeze

• Frozen then thawed, warmed but not fed: Do not refreeze

• Frozen then thawed, warmed and fed: Discard

 References

Jones, F. Best Practices for Expressing, Storing and Handling Human Milk, 3rd edition. Raleigh, NC: Human Milk Banking Association of North America, 2011.

Mohrbacher, N. Breastfeeding Answers Made Simple. Amarillo, TX: Hale Publishing, 2010.