Breast milk, just like most other foods, begins to get sour and smell bad and deteriorate after some time, hence becoming unsafe for consumption.
But, amazingly, it can sit out at room temperature longer than infant formula and even some foods.
So what’s the science behind it? Well, apparently, breast milk has antibacterial and immune properties that keep off bad bacteria from growing inside it for many hours. But, the longer it is left out, the more time bad bacteria have to multiply.
The real question then is, how long is too long? We will be answering this question just next.
Freshly Express Milk Period to Go Bad
Freshly expressed milk – remains safe at room temperature (77℉/25°C) or less for 4 to 6 hours. Temperatures play a huge part in the growth of bacteria. The higher the temperature, the faster the bacteria grow. So try not to leave the milk out if temperatures are higher than the ones stated above.
Refrigerated breast Milk Period to Go Bad
Refrigerated breast milk (40°F /4°C) – stays fresh for up to 4 days. However, if it was previously frozen, it should be used within 24 hours. Experts recommend that you keep the milk in the back of the fridge, not by the door, so it isn’t affected by the warmer air coming in every time the door is opened.
Frozen breast Milk Period to Go Bad
Frozen breast milk (0°F /-18°C) or colder – it largely depends on the type of freezer you have. If it’s a deep freezer, the milk can be preserved for up to 12 months, but 6 months is optimal. If stored in the freezer in your fridge opened from the same door as the rest of the refrigerator, the milk is only good for 2 weeks. If the freezer compartment has its own door, the milk can last 3 to 6 months.
Also, note that you should never refreeze breast milk after thawing.
If you pump away from home- keep the milk in an insulated cooler with ice packs. It should last for 24 hours.
Reheated breast milk- should be consumed within one hour. If the baby doesn’t finish the bottle, you can refrigerate it if it has not been more than 30 minutes since your baby fed, and you can reheat only one more time.
As you have seen, you have many options to store your liquid gold as a mom. You can refrigerate, freeze, or even leave it out for a few hours. But, for your baby to get the best quality nourishment, it’s good to follow these guidelines that we have gathered from the Centers for Disease Control and Prevention (CDC). The Academy of Breastfeeding Medicine (ABM) and AAP also recommend the same.
Things to keep in mind
- Research shows that the longer you keep breast milk- whether in the fridge or freezer- the more it losses Vitamin C.
- Breast milk changes to the baby’s needs. This means that breast milk expressed when a baby is an infant can’t meet the same baby’s needs a few months on.
- The guidelines we have shared above apply to healthy full-term babies. Doctors may recommend otherwise for preterm, sick, or hospitalized babies.
Jane Lanbert is a mother of two and works as an elementary school teacher. Jane joined Motherhood HQ to provide expertise on product testing after her stint at Consumer Reports. Jane loves reading and getting immersed in new research on various topics from parenting to pet psychology. When not reading or testing baby gear to review, Jane enjoys hiking in the midwest and hanging out with their two dog pets. Jane is originally from Salt Lake City, Utah, and holds a degree in Elementary Teaching. She can be reached at email@example.com