You can safely heat both refrigerated and frozen breast milk in warm water.
Bottle warmers can also help, but they can overheat breast milk.
Warming the stored breast milk before serving it to your baby is a personal choice. Many babies prefer warm breastmilk if they take it from a bottle, since breastmilk is warm when the baby is breastfed.
Warming breastmilk also helps to maintain its consistency after it has been stored.
When breastmilk is frozen or refrigerated, the fat tends to separate in the bottle. Heating breast milk, or at least bringing it to room temperature, can help you more easily mix breast milk to its original consistency.
How to warm breast milk from the refrigerator
To heat breast milk from the refrigerator:
- Take breast milk from the fridge and set it aside
- Heat the water using a kettle or microwave. Pour hot (not boiling) water into a cup or bowl
- Place the sealed bag or breast milk bottle in the bowl of warm water. The milk must be stored in a sealed container for heating.
- Leave the milk in warm water for 1-2 minutes until the breast milk reaches the desired temperature. With clean hands, pour the breast milk into a bottle or, if it is already in the bottle, screw the teat.
- Shake the breast milk (never shake it) to mix with the fat, if it is separated.
Before offering the bottle to the baby, check the temperature of breast milk by pouring some on the wrist.
To prevent germs from getting into the milk, avoid dipping your finger into the bottle.
You can also heat the milk by holding the sealed bag or bottle under very hot tap water.
But it takes longer and wastes water (not too environmentally friendly).
How to warm breast milk from the freezer
To heat frozen breast milk, remove it from the freezer and place it in the refrigerator to defrost overnight. Then, follow the same instructions for warming breast milk from the refrigerator.
If you need milk right away and all you have is frozen milk, you can warm breast milk directly from the freezer using the same method you would use to warm it from the refrigerator.
The only difference is that you will have to keep it in hot water for 10 to 15 minutes or more.
Can breast milk be heated in the microwave?
Never put breast milk in the microwave: microwaves do not heat food evenly, so they can create hot spots that can burn the baby.
Microwaves are also believed to damage the nutrients and antibodies in breast milk.
However, you can use a microwave oven to heat the water used to warm breast milk.
Does it make sense to buy a bottle warmer?
Some parents swear to use a bottle warmer to warm breast milk or infant formula.
Manufacturers of bottle warmers claim that these devices heat more evenly than a microwave oven.
However, opinions differ as to whether they are actually useful or easier than soaking breast milk in hot water.
The potential disadvantage of a bottle warmer is the increased chance of overheating breast milk and killing the beneficial nutrients.
How to heat breast milk in a bottle warmer
To heat the breast milk in a bottle warmer, place the entire bottle in the heating area and follow the instructions in the manual.
Most bottle warmers take a few minutes to achieve the desired heat. Keep an eye on the bottle warmer so it doesn’t overheat and unplug it when not in use.
Is it possible to reuse previously heated breast milk?
We do not recommend that you heat the previously heated breast milk.
Sometimes babies start sucking but do not finish the whole bottle: after two hours of sitting, it is better to throw away the advanced breast milk. This helps to prevent milk from going bad or being introduced into germs in the environment.
How long is the excised breast milk good for? The safety of omitted breast milk will vary greatly depending on the overall levels of bacteria in the environment.
Breast milk is good at room temperature (25°C) for:
- Four hours for fresh breast milk: after four hours you should use it, store it or discard it.
- Two hours for previously stored and thawed breast milk. Discard unused breast milk and defrost after two hours. Do not re-freeze or heat frozen and thawed breast milk.
General tips for using warmed breast milk
Remember to always keep breast milk covered with a lid when it is out of the refrigerator (but also inside).
At least one study indicates that breast milk can be stored in an insulated refrigerator with ice packs for up to 24 hours. Always use specific bottles and bags for freezing breast milk.
How to use and store breast milk
Plan to store breast milk in single doses depending on how much your baby typically takes in a single feeding: this can help to reduce the amount of unused breast milk that you will later have to eliminate.
Always label the breast milk with the date it was squeezed and first use the stored older breast milk to keep the rotation cool.
How long can milk be stored in the freezer and refrigerator?
Breast milk can be stored in the refrigerator for four days and in the freezer for up to 12 months.
However, after 90 days, the acidity of breast milk may increase and nutrients may decrease. Therefore, for the best quality, plan to use frozen breast milk within six months of when it was extracted.
You can mix and store extracted breast milk on different days, but always use it according to the earliest, oldest date. And never add fresh breast milk to already frozen breast milk.
In general, refrigerated breast milk is better than frozen because it is fresher, and nutrients and antibodies will be more suitable for the needs of the baby.
