Be that as it may, the temperature range of typical domestic freezer is generally −18°C to −20°C and human breastmilk frozen storage at home is not usually pasteurized before freezing, and so the rancid-flavor development of breastmilk due to lipolysis is generally inevitable under the typical frozen-storage regime.
If the baby continues to refuse the frozen milk due to its taste, you can discard it or donate to the human milk bank near you. The pasteurization process destroys lipase. The milk bank will accept frozen milk that has been frozen for 8 months or less and has not received any heat treatment.
When you freeze breast milk, this protective membrane gets destroyed and lipase is free to break down all the fat molecules it can. If you have high lipase milk, this can cause your milk to have a soapy or sweaty taste.
Freezing Habits and Lipase
Freezing and thawing breast milk can have a big impact on taste and smell. Some moms notice that after defrosting, their milk smells unpleasant – soapy or even sour. This is normal! Breast milk contains lipase, an enzyme that is normally present in human milk and has a lot of benefits.
The milk is likely to have a very distinctive sour smell and may even taste metallic, like soap or bitter. If it smells sour, it is very likely because of the lipase enzyme's action on the fat content of breast milk.
However, extra lipase can speed up this process, which can make the milk taste sour or soapy after some time has passed. (You might also find that your breast milk smells like vomit, or eggs, or metallic.)
Sometimes this can change the smell or taste of breast milk. Some people say the milk smells like soap or tastes sour. Even though we may notice changes to the milk after thawing, most babies do not. If this is happening and your baby is refusing thawed milk, try scalding your milk after pumping.
Breastmilk should taste slightly sweet and have almost no odor to it. Taste and smell test every few hours for 48 hours – if your milk starts to smell, then most likely it's high lipase. If not, may have just been a spoiled bag! Check out the CDC guidelines for breastmilk storage here.
Sometimes stored breast milk is described as tasting very sour or rancid after storage in the fridge but particularly after freezing and thawing. Although generally still thought safe to drink, some babies will refuse previously stored milk that now has a strong sour taste or smell.
Lipase helps to break down the fats in breast milk, making it easier for babies to digest. Women who have a lot of lipase in their milk find that it continues to break down the fats even when the milk is frozen, resulting in a soapy or rancid odor when the milk is thawed.
Enzyme activity.
But some people have overactive enzymes that move faster than normal. This can create a fishy or soapy odor in breast milk that you pump and save for later. It can even affect the taste. Sometimes your baby won't have a problem with the milk, but other times they may refuse to drink.
Some common consequences can be mentioned: Diarrhea: Similar to adults eating expired food, digestive disorders; Babies fed spoiled breast milk may develop diarrhea soon after.
But when lipase activity is excessively high, it breaks down fat too quickly, which can lead to breast milk that tastes or smells soapy or metallic. These changes can be noticeable after your milk has been pumped and stored. Only a small number of women have excess lipase activity in their breast milk.
Fresh breastmilk contains the most active anti-infective properties, followed by refrigerated breastmilk, and then frozen breastmilk.
At room temperature (77°F or colder) for up to 4 hours. In the refrigerator for up to 4 days. In the freezer for about 6 months is best; up to 12 months is acceptable. Although freezing keeps food safe almost indefinitely, recommended storage times are important to follow for best quality.
What to Do if You Have High Lipase Milk. "If the baby doesn't mind the milk, there's nothing for a family to do about it,” says Nelson. In other words, your baby can safely drink it, regardless of that soapy taste or smell.
Frozen breast milk often separates into a yellowish layer on top and a thinner layer below because of the fat distribution. You may hear breast milk experts refer to “foremilk” and “hindmilk.” Thin foremilk often comes out of a breast that hasn't been pumped or fed from in a while.
So it's important to follow the safety guidelines for the collection and storage of breast milk. When you freeze breast milk, it loses some of its healthy immune factors, but not all.
As long as the temperature of the freezer is 0°F or below, it does not matter whether it is a kitchen freezer or a deep freezer. Breast milk can be stored in the freezer (at 0° F or colder) for up to 12 months, although using it within 6 months is best.
Once breast milk is warmed to temperatures higher than 104F/40 C (for perspective, 104F is what most of us would describe as warm, and is the normal limit for hot tubs), breast milk's nutritional and immunological value begins to deteriorate.
Other times, the amount of lipase in the milk you pumped might have gotten worse over time, so the older milk might be fine. Also, sometimes how quickly the milk was frozen may make a difference. Milk that was frozen right away versus sitting in the fridge for a few days first might not be as affected.
While it is not common, occasionally a high level of lipase can also cause frozen or stored milk to have what parents have called an “odd smell” or a “soapy or fishy” smell. This does not harm the baby, so there is no need to discard the milk unless your baby rejects it.
Yes! We will happily accept your high lipase milk, as will our recipient babies. Lipase is destroyed during our pasteurization process. Just make sure not to heat your milk before donating it.