Babies often reject frozen breast milk because high lipase enzyme activity or chemical oxidation changes the taste to soapy, metallic, or rancid, even though it's safe; scalding fresh milk before freezing stops lipase, or you can mix thawed milk with fresh, add a touch of vanilla, serve it cool, or use it in solids to help acceptance.
As others have said, mix it with fresh milk! That did the trick for me. So try a 50/50 mix and slowly raise and lower levels of fresh and frozen to try and have your baby take more frozen.
Mixing frozen with fresh, scalding and adding alcohol free vanilla have all been reported to work if baby doesn't take it straight up.
Even when breast milk is stored correctly, it can sometimes develop a distinct smell or taste over time due to a natural enzyme called lipase, which breaks down fats in the milk. Some babies don't mind this change, but others, especially if they're sensitive, can become fussy or uncomfortable after drinking it.
The "4-4-4 rule" for breast milk is a simple storage guideline: fresh milk is good for 4 hours at room temperature (up to 77°F/25°C), for 4 days in the refrigerator (39°F/4°C or colder), and up to 4-6 months (or longer) in a standard freezer (0°F/-18°C). It's a handy mnemonic, though some organizations like the CDC recommend up to 6 months in the freezer and the AAP up to 9 months, with deeper freezers offering even longer storage.
Before feeding, check the milk for any unusual odor, separation, or strange taste to ensure it is safe for the baby. Once thawed, breast milk should be used within 5 days if re-stored in the refrigerator.
At around 6 weeks, many moms introduce the pump and follow the Magic 8 method — pumping 8 times in 24 hours to help build and maintain milk supply.
Stored milk has time for the lipase to take effect resulting in changes to taste and smell. Some women report a soapy or metallic smell while others notice a distinctly fishy whiff. This usually doesn't occur in freshly expressed milk.
You can scald your milk (lots of info on how to do this if you search), but personally I just freeze ASAP and it seems mostly fine. When giving baby thawed milk I add 1 drop of alcohol free vanilla extract per frozen oz to ensure it tastes better.
Previously frozen breast milk has similar nutrient and antibody content to fresh milk. It does lose a small amount of those qualities but can still provide a baby with the nutrition it needs.
Symptoms include:
Rule #2: The Breast Milk Storage Guidelines.
The 4-4-4 Rule. Or the 6-6-6 rule. Basically, breast milk is good at room temperature for 4 or 6 hours, in the refrigerator for 4 or 6 days, and in the freezer for 4 or 6 or 12 months.
The longer milk is kept at room temperature or even in the refrigerator before being frozen, the more lipase activity it will have. Milk that has a high level of lipase can develop a soapy smell and taste, but is not harmful to the baby.
The 5-5-5 rule for breast milk is a simple guideline for storage: freshly expressed milk lasts up to 5 hours at room temperature, up to 5 days in the refrigerator, and up to 5 months in a standard freezer, though the CDC notes it can be frozen for up to 12 months for best quality within 6 months. Always label containers with the date and time, use small batches (2-4 oz), and place milk in the back of the fridge or freezer for consistent temperature.
Thaw milk under lukewarm running water, in a container of lukewarm water, or overnight in the refrigerator. Never thaw or heat milk in a microwave. Microwaving destroys nutrients and creates hot spots, which can burn a baby's mouth.
Scald your breastmilk to reduce high lipase.
Background: Infant refusal to feed previously frozen human milk is thought possibly attributable to lipase, an enzyme that cleaves fatty acids from milk triglycerides potentially changing the taste of the milk.
Thawing and Warming Breast Milk
To thaw frozen milk, hold the frozen bottle or bag under lukewarm running water. You can also thaw it in the refrigerator or in a bowl of warm water. Swirl the milk gently to mix.
The "4-4-4 rule" for breast milk is a simple storage guideline: fresh milk is good for 4 hours at room temperature (up to 77°F/25°C), for 4 days in the refrigerator (39°F/4°C or colder), and up to 4-6 months (or longer) in a standard freezer (0°F/-18°C). It's a handy mnemonic, though some organizations like the CDC recommend up to 6 months in the freezer and the AAP up to 9 months, with deeper freezers offering even longer storage.
You can't see lipase, but changes in taste or smell can indicate its presence. The most notable signs of high lipase milk are changes in taste and smell. You might notice your milk having a scent or taste similar to metallic, vomit, eggs, soap, or fishy.
The Academy of American Pediatrics assures that even though high lipase milk may have an unpleasant odor and even an unpleasant taste, it's not unhealthy for babies to drink. It doesn't cause upset tummies, introduce unhealthy bacteria, or alter the nutritional content of the breast milk.
(If you're wondering whether babies can smell breast milk at night, the answer is yes!) In addition, breast milk is higher in fat content during this nighttime hours, too, which is great for your little one's fast-developing brain.
The American Academy of Pediatrics and the World Health Organization recommend continued breastfeeding along with introducing appropriate complementary foods for up to 2 years or longer.
“I think with a lot of men, there's just a curiosity of what it tastes like, and what it would be like to nurse,” said Wendy Haldeman, who co-founded the Pump Station with Harvey. “Certainly men suck on nipples during sex, so they're gonna get milk.” But husband breastfeeding can be as much about utility as curiosity.
The 4 4 4 rule means breastfeeding or pumping every 4 hours, for at least 4 days, and continuing for about 4 weeks to support milk supply. This steady routine helps signal the body to make more milk.