What happens if I mix warm breast milk with cold breast milk?

The Risks of Mixing Warm and Cold Breast Milk
Mixing warm breast milk with cold breast milk is a topic that often raises questions among new mothers. While it may seem convenient to combine different temperatures of milk, health experts generally advise against this practice due to potential risks associated with bacterial growth.
Bacterial Growth Concerns
When warm breast milk is added to cold breast milk, the temperature of the chilled milk rises. This increase in temperature can create an environment conducive to bacterial growth. According to guidelines from reputable health organizations like the CDC and the Academy of Breastfeeding Medicine, combining these two temperatures can lead to the rewarming of previously stored milk, which is not recommended . The concern is that the warm milk can elevate the temperature of the cold milk, allowing bacteria that may be present to multiply more rapidly.
Best Practices for Mixing Milk
Experts recommend that if you do choose to mix breast milk, it’s crucial to cool any freshly expressed milk before combining it with refrigerated milk. This practice helps maintain the lower temperature of the stored milk, thereby minimizing the risk of bacterial proliferation . If the intention is to feed the milk immediately after mixing, the risks are significantly reduced, as there would be little time for bacteria to grow.
The Controversy and Variability in Advice
Despite the general consensus on the risks, there are varying opinions among lactation consultants and pediatricians. Some mothers report that they have successfully mixed warm and cold milk without any issues, citing personal experiences and advice from their healthcare providers. However, these anecdotal accounts do not negate the established guidelines that emphasize caution.
Conclusion
In summary, while mixing warm and cold breast milk may seem like a practical solution for busy parents, it is fraught with potential health risks. The safest approach is to cool freshly expressed milk before combining it with refrigerated milk, or to feed the milk immediately after mixing. By adhering to these guidelines, parents can help ensure the safety and health of their infants.

How long can refrigerated breast milk be left out at room temperature?

Freshly expressed or pumped milk can be stored: 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.

Can breast milk be warmed and refrigerated again?

Warmed milk from the fridge should be used within two hours. If it’s not used, it should be thrown away. “Once your milk is warmed, the ability of the milk to inhibit bacterial growth is decreased, so it is not recommended to place your milk back in the refrigerator,” explains Andria.

What is the 5 5 5 rule for breast milk?

Something I recommend to moms is the 5-5-5 rule. Try and use milk within five hours at room temperature, five days in the fridge, and by five months in the freezer.

What happens when you add heat to milk?

Milk is made up of water, fats, carbs, and protein. When you heat it, the water starts to evaporate, and the other components begin to separate. Bringing it to a boil too quickly can burn the sugars and curdle the whey protein. That causes scorching on the bottom of your pan and a skin to form on top.

Is mixing hot milk with cold milk bad?

The official recommendation is not to mix fresh (warm) and cold milk, as the fresh milk could raise the temperature of the cold milk and allow for bacterial growth.

Can you mix warm breast milk with refrigerated breast milk?

Our IBCLC always said you can safely mix warm and cold – but to try to add no more than 50% of the cold as warm. So if there are 2 oz chilled, to add only 1oz warm. Adjust for bigger amounts. That way the milk cools back down quickly.

What happens if you accidentally put an extra scoop of formula?

If it happens once, you probably won’t notice much of a change with your baby’s routine. If it happens many times, problems can occur. Repeatedly over-mixing formula2 over time can have serious side effects like: Dehydration.

Can I mix morning and evening breast milk?

If you pump or hand express your breast milk at different times, you wonder if you can mix breast milk from different days into one storage container. Most of the time, combining breast milk is acceptable unless you have a preterm baby or you’re in an unclean environment.

How to know if breastmilk is spoiled?

It will also smell bad, much like spoiled cow’s milk. And, like spoiled cow’s milk, breast milk that’s old will taste sour. (It’s fine to taste your breast milk to check!) Always label your pumped milk with a time and date so you can tell how old it is.

Can you mix warm breast milk with cold formula?

A safe temperature generally refers to ensuring that both the formula and breast milk are within a similar temperature range. It’s okay to mix them when one is slightly warmer or colder than the other, but it’s essential to avoid extreme temperature differences.