How long does breast milk last?

Doctors often disagree with one another, but there’s one thing that you won’t need a second opinion on: breastfeeding is the healthiest way to feed an infant. In fact, the American Academy of Pediatrics (AAP) and World Health Organization (WHO) agree that babies should breastfeed exclusively for the first six months of life. The WHO takes it a step further, suggesting that moms consider feeding their children breast milk through the age of two.

The downside to exclusive breastfeeding is the level of involvement. Infants can eat as often as 12 times each day, which means that unless every day at the office is ‘bring your baby to work day,’ working moms aren’t always around to feed or nurse their children on-demand. This is where breast milk pumping comes in.

Pumping and storing breast milk is a great way to get your child the health benefits of breast milk, even when you aren’t always there to nurse them. But as anybody who has gone on vacation with a gallon of milk hiding in the back of their fridge knows, milk only lasts for so long. So how long is too long to store pumped breast milk?

The CDC recommends the following:

Storage Location and Temperatures

Type of Breast Milk


77F (25C) or colder (room temperature)


40F (4C)


0F (-18C) or colder

Freshly Expressed or Pumped

Up to 4 Hours

Up to 4 Days

Within 6 months is best

Up to 12 months is acceptable

Thawed, Previously Frozen

1-2 hours

Up to 1 Day

(24 hours)

NEVER refreeze human milk after it has been thawed

Leftover from a Feeding (baby did not finish the bottle)

Use within 2 hours after the baby is finished feeding


When referring to breast milk storage guidelines, it is important to understand that the freshness of milk isn’t determined by a single temperature in a single moment. Instead, the guidelines provide information about the lifespan of your milk’s freshness at a certain temperature over time. This is why storing milk at a consistent temperature is so important.  

Thawed milk, when does the 24-hour countdown start?

One common misconception around thawed breast milk is when to start the 24-hour countdown. The 24-hour countdown doesn’t begin when you move frozen milk into the fridge. Instead, it begins when the last ice crystal thaws.

Stored milk and excess lipase

If you have stored your breast milk according to the proper guidelines, but notice a sour or soapy smell in your thawed breast milk, it may mean that you have a higher than normal level of lipase in your breast milk. Lipase is an enzyme responsible for breaking down fat in breast milk, which makes it easier for babies to digest. Breast milk that is high in lipase can take on a bit of a funky smell the longer it’s stored, but it’s still safe for babies to eat. Some babies may reject thawed breast milk that is high in lipase, but if they do accept it, they aren’t at risk of any harm. Moms of babies who refuse milk that has developed a smell due to lipase can neutralize the lipase by scalding the milk before freezing it. 

Milk Stork helps you get your breast milk home from anywhere in the world

Moms who travel for work won’t always be home to nurse their infants. Fortunately, Milk Stork provides traveling moms with a variety of different options for toting or shipping breast milk back home to their babies.  

Milk Stork provides everything you need to ship, tote or check your breast milk. Domestic or international, refrigerated or frozen, a day’s supply or a larger stash, Milk Stork has a size and solution for every mom’s needs. 

You can learn more about Milk Stork’s service, which options your employer offers and get started today, by tapping the button below.


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