Breast milk is an essential source of nutrients for breast-fed babies, but, like all milk, it’s also vulnerable to spoiling.
How long does it take for breast milk to expire?
If you’ve read conflicting information, that’s because different organizations related to health and breastfeeding offer varying numbers of hours and days that milk can be stored in different locations. We’ll provide a range for you! And always, if you’re just not sure if you’ll use milk soon after it is pumped or you are busy with lots of tasks, it’s best to put it in the fridge for safekeeping. You worked hard for that milk, don’t let it accidentally spoil!
But before you pump, it’s great to keep some safe pumping guidelines in mind:
- Squeaky clean
All soon-to-be-filled baby bottles should be washed by hand or run through a dishwasher before any pumping session. They also need to be very dry. You’ll want to give your hands a good, long wash with soap and hot water to get rid of any bacteria that could get into your milk during the pumping and bottling/bagging process. - Get into cold storage, STAT!
Breast milk may be stored at room temperature for a short time, but it does more easily spoil at room temperature, so sticking it in the fridge or freezer as soon as possible helps prevent milk loss. - Know your milk’s limits
Breast milk can be stored at room temperature for 6 to 8 hours safely, but that’s only true if the room temperature isn’t too warm. More conservative time keeping is 4 hours at room temp. Milk containers should be covered and kept out of direct sunlight. Ideally, it isn’t warmer than 77 degrees Fahrenheit or 25 degrees Celsius where the milk is sitting out.
Breast milk can be refrigerated for up to eight days, but three to five days is ideal. For longer-term storage, parents can also choose to freeze milk for use later. This option is safe and often more convenient, but it should only be done within safety guidelines for freezing. As long as your freezer has its own separate door, you can safely store frozen breast milk for up to one year, although 6 months is ideal.
- Room temp: 4 to 8 hours
- Refrigerated: max 8 days
- Frozen: 6 months to one year
When in doubt, look at and smell your milk. Although milk will separate and have a fatty layer on top, it should not be clumpy (chunks of ice during a thaw are okay). It should have a faint or sweet smell when fresh, or will smell pretty awful and rotten if it’s spoiled. If you notice a soapy or metallic smell in expressed milk, it could be high lipase. This is an enzyme, and although it changes the smell of milk over time, high lipase milk is perfectly safe and happens to folks for reasons we don’t quite understand. The only risk with high-lipase milk is that your baby won’t like the taste. Rest assured, there are many ways to work around this, but offering this milk early on can let you know if you have a flexible baby or may need some tips and troubleshooting.
Reviewed by the Ovia Health by Labcorp Clinical Team
Sources
- “ABM Clinical Protocol #8: Human Milk Storage Information for Home Use for Full-Term Infants.” BREASTFEEDING MEDICINE Volume 12, Number 7, 2017 Mary Ann Liebert, Inc. DOI: 10.1089/bfm.2017.29047.aje
- “Breastmilk Storage and Preparation.” Centers for Disease Control and Prevention. U.S. Department of Health & Human Services, May 16, 2025 Web
- DiMaggio, D. “Tips for Freezing and Refrigerating Breast Milk.” Healthy Children. American Academy of Pediatrics, March 3 2023. https://www.healthychildren.org/English/ages-stages/baby/breastfeeding/Pages/Storing-and-Preparing-Expressed-Breast-Milk.aspx.
