When I started breastfeeding, I was worried about somehow ruining my boob juice. Although I continuously checked and re-checked the storage guidelines for the correct amount of time breast milk could be stored, I was always worried it would go bad without me realizing it. This can create even more concern for moms who are getting their breast milk from donors. That's why learning how to tell if your breast milk is contaminated is of the utmost importance.
But first, it's important to address there are potentially two different concerns at hand. One is in relation to whether breast milk you're currently storing has gone bad, and the other is whether or not breast milk may have been contaminated before reaching you.
The more common concern for moms storing breast milk is whether you can tell if breast milk has gone bad or is still good. For the most part, if you're following breast milk storage guidelines, you don't need to worry. If, however, you find yourself unsure or concerned that your stored breast milk has gone bad, IBCLC Rachael Anastasio Collins tells Romper that an easy way to know is the smell. She says bad breast milk will smell awful – much like any spoiled milk. That being said, if you notice that your breast milk smells soapy or has a metallic odor, Collins says that usually indicates a high level of the enzyme Lipase, which isn't concerning. This enzyme is present in all breast milk and not hurtful in anyway.
There are a few other obvious signs your breast milk has gone bad, including if it contains chunks, isn't mixing well, or wasn't sealed correctly. If you haven't followed breast milk storage guidelines and your breast milk's been in the fridge longer than three to five days, there's a good chance it may have spoiled as well. If you really want to test it out, you can always taste it. Much like the stench of any spoiled milk, breast milk that's gone bad will also taste sour.
Beyond the concern of stored milk that's gone bad, mother's who take advantage of donated milk may have some concerns about contaminated breast milk. In order to help avoid this worry, IBCLC and owner of Tiny Tummy Lactation Services Tori Sproat tells Romper that it's important not to buy online (or buy at all) and instead use reputable resources like Eats on Feets or Human Milk 4 Human Babies. Additionally, Sproat says that research shows local peer-to-peer, free breast milk sharing is very safe, and instead the primary risk of contamination occurs when shipping or purchasing breast milk. The risk of shipping breast milk is that it can easily go bad if not stored correctly. Although the main concerns that arise from purchasing breast milk are the risk taken by using someone who's turning a profit and potentially diluting milk or storing/caring for milk in an unregulated environment.
Lactation consultant and registered nurse Tera Hamann also tells Romper that there's no way to tell what medications, supplements, or drugs a donor may be taking if you're not going through a legitimate source or unable to screen your donor. Unless you want to send your breast milk to a lab to be tested, dilution and contamination from donated milk is not easily detectible. So in these cases, it's best to play it safe, go through reputable, local sources, and you shouldn't have to worry about contamination. Also keep in mind the signs to look for if you're concerned milk has gone bad, whether it's donated or stored straight from the tap.