Whether you're exclusively pumping, doing a combination of pumping and nursing, or only pump as needed, there is a lot to get used to in the vast realm of pumping and handling your breast milk. Namely, figuring out how to safely store the milk you aren't going to use right away. Like most nutritional substances, breast milk will spoil if it's left out for too long. But just how long does breast milk last at room temperature? It's definitely an important question to ask.

Breastfeeding Basics noted that's pretty easy to tell if your breast milk has been sitting out too long (it will smell TERRIBLE), and drinking spoiled milk will make your baby sick, just like eating any other kind of spoiled food will. So it's essential that you're taking the right steps to store your breast milk in the safest way possible.

According to Mayo Clinic, freshly expressed breast milk can be left at room temperature for up to six hours, but using it within four is ideal. If the room is particularly hot, the limit is four hours. After this point, you can refrigerate the milk, freeze it, or obviously feed it to your child. The same rule applies to milk that you've set out to thaw or cool down from the fridge. Once the milk has reached room temperature, letting it sit for longer than four to six hours is definitely not recommended.

La Leche League also notes that once you've set the milk out, it should be in a sanitary, closed container, like a bottle or breast milk storage bag. Leaving your milk in an open container leaves room for contaminants and bacteria to grow.

As complex as breast milk is, and as different as every mother and child's breastfeeding journey is, it's important to know the basics about not only pumping and nursing, but storing your milk as well, to ensure that your baby gets the best of the best.