Skip to main content

Human Milk Storage Guidelines

There are moments when mom simply can’t breastfeed herself. Either because she has to go to an important conference, is sick, or simply wants her partner to take over a meal. Pumped breast milk is ideal for such moments.

You can store it in the refrigerator for up to three days or even in the freezer for up to six months.

But what do you have to watch out for when freezing breast milk? And why can’t breast milk be defrosted in the microwave? We explain these and many other topics in our article.

Breast Milk Storage Solutions

Milkies Organize & Store Your Breast Milk

 4,9 Rating

Breast milk patented storage system that fits in your freezer. Simply collect your precious breast milk in a milk storage bag, and place the bag on the metal quick-freeze tray at the top of the Freeze.

  • Stores up to 60 ounces of breast milk in most milk storage bag brands.
  • A Metal “quick-freeze” tray facilitates rapid freezing.
  • Contains no BPA or phthalates.

The Milkies Freeze is the answer to all your breast milk storage hassles and concerns. Simply collect your precious breast milk in a milk storage bag, and place the bag on the metal quick-freeze tray at the top of the Freeze. The Milkies Freeze can store up to 60 ounces of breast milk.


Hours of research


Products Reviewed



Storing breast milk after expressing: Advice & Tips

Breast milk thawing: The most important questions and answers

Breast milk thawing: Tips & Advice

The most important facts in brief

  • Breast milk contains important growth factors, antibodies and nutrients that your child needs, especially in the first months. By freezing breast milk, you can preserve it for up to 6 months. Even though the fat and calorie content decreases, breast milk still retains most of the important nutrients.
  • When thawing frozen breast milk, the motto is to do it as slowly as possible. This works best overnight in the refrigerator. This principle is exactly the opposite of freezing. Here, fresh breast milk should be chilled as quickly as possible.
  • Once thawed, breast milk should not be frozen again. Instead, your child should drink the warmed milk as soon as possible, because at room temperature it keeps for just two hours.

Best Milk Storage Organizers Review

Medela Breast Milk Storage Bags

  • Ready to Use Breast milk Bags for Breastfeeding.
  • Hygienically Pre-Sealed.
  • Durable double-dated material

 4,8 Rating

Check Price

These ready to use breastmilk storage bags are constructed from a durable, double-layer material with a built-in double zipper seal to keep your breastmilk safely stored in the fridge or freezer.

Philips Avent Baby Bottle Warmer

  • Heats 4 ounces of milk in 3 minutes.
  • Power consumption: 300 Watts.
  • BPA Free, Phthalate Free, Latex Free, Lead Free.

 4,8 Rating

Check Price

Philips Avent Fast bottle warmer is a safe and easy way to make mealtime more comfortable for your baby. Once switched on, the warmer gently heats bottles and baby food within 3 minutes.

The First Years Breastflow Milk Storage Organizer

  • Holds Up To: 20 milk storage bags.
  • Spring-Loaded Drawer.
  • Dishwasher safe.

 4,8 Rating

Check Price

The Breast Milk Storage Organizer has a spring-loaded drawer. Snap the cover on to keep breast milk isolated from other items in the freezer, or you can use it to hold bags for extra storage.

Why is breast milk so healthy for your baby?

The formation of breast milk begins as early as halfway through the pregnancy. This ensures a supply even for premature babies. But what makes breast milk so special?

  • Intestinal flora: The sugar molecules present in breast milk is supposed to serve as fertilizer for bacteria that settle in the intestinal flora. Bacteria in our intestines (microbiome) are important for our digestion and intestinal health. Likewise, more and more studies are showing that intestinal flora plays a crucial role in metabolism.
  • Defensive substances: Especially in the first months, breast milk contains an enormous amount of antibodies and bioactive proteins. This protects your child’s immune system. After about one to two months, your child already takes over the defense against pathogens on its own and the proportion of antibodies in breast milk decreases.
  • Weight gain: In the course of breastfeeding, the fat content of breast milk increases. This is mainly so that your child grows and has energy for further development.

Breast milk is therefore the perfect food to accompany your child safely through the first months. The decision of whether and how long the newborn is breastfed is ultimately left to the mother. We think that, with regard to the needs of the child, each family should decide for itself.

What you should know about thawing breast milk: background

Especially when you can’t be with your child, pumped and thawed breast milk is perfect. This way, you can go to your own doctor’s appointment or weekly exercise as normal and not have to worry about your baby’s meal.

Breast milk is still the best food for your child in professional circles. To preserve the important nutrients after freezing, there are a few things you should keep in mind. Hygiene measures are also important so that your child does not absorb harmful substances.

  • What is the best way to thaw breast milk?

You have several options for thawing frozen breast milk. Basically, you should be careful and especially not use too high temperatures, otherwise, important nutrients will be lost.

    • Refrigerator: The best and most gentle method is to thaw breast milk in the refrigerator. Simply place the frozen portion in the refrigerator overnight. It is best not to put it in the door so that temperature fluctuations are avoided. Keep in mind that thawing takes about 12 hours, so you’ll need to plan ahead.
    • Water bath: Defrosting in a water bath is somewhat faster. For this, use water that is at most lukewarm, i.e. 37 degrees Celsius. It is best to place the bottles or bags with the frozen milk in cold water first. As soon as the breast milk begins to thaw, you can change the water. Of course, you can also hold the bottles or bags under running water. Again, the temperature should never be warmer than lukewarm.
    • Bottle warmer: Many bottle warmers have an integrated defrost function. This makes thawing easier and is also the fastest way to provide frozen breast milk for your baby.
      Thawed breast milk is best drunk directly by your child. At room temperature, the milk will only keep for a maximum of two hours. It can be stored in the refrigerator for a maximum of 24 hours. Once you have started breast milk, you should not give it to your child again. The saliva and other germs can cause bacteria to multiply if you leave the bottle in the refrigerator for a long time.
    • Once thawed, breast milk should never be refrozen.

Never thaw frozen breast milk in the microwave. For one thing, high temperatures destroy important nutrients. For another, the milk will be heated unevenly, creating colder and hotter spots. Your child can get scalded quickly.

  • How long does it take to thaw breast milk?

Basically, the longer it takes to defrost, the more gently the milk is treated and the more nutrients it retains.
The refrigerator is, therefore, the most suitable place. Here, breast milk needs about 8 to 12 hours to thaw. At the front, the refrigerator is usually a little warmer, so it can all be thawed hereafter just 8 hours. After about 8 hours, stir the milk with a small spoon and see if you can still find frozen pieces. If so, put the milk back in the fridge and try again in two hours.
When defrosting in a water bath or under the tap, you can be ready after just a few minutes. However, gentle heating is better here as well. Therefore, it is best to start with cold water and change it as soon as the breast milk begins to thaw.

Defrosting is quickest in a bottle warmer. After a few minutes, the breast milk should be thawed. It is particularly practical here that you can heat defrosted milk directly to the body or at room temperature. This usually happens quickly within 3 to 5 minutes.

  • How long can I store breast milk?

Depending on the storage location, different storage times apply. The following recommendations apply to hygienically and safely expressed breast milk and term babies. Before each feeding, check that the thawed breast milk is still edible.

  • Room temperature 59-77 °F (15 – 25 degrees °C) Approx. 4 hours.
  • Refrigerator (39,2 °F (4 degrees °C) or colder) Approx. 2-3 days.
  • Freezer (-4,0 °F (-20 °C) degrees or colder) Maximum 6 months.

The following table gives you an overview of the storage time for breast milk thawed in the refrigerator:

  • At room temperature 59-77 °F (15-25 degrees °C) maximum 2 hours.
  • In the refrigerator Up to 24 hours.

If your child is receiving special treatment or is in a premature care unit, different guidelines may apply. Be sure to check with your hospital.

It is best to always write the pumping date and, if necessary, time on the pouches or bottles, so you know exactly when you can still use the breast milk without any problems.

In addition, breast milk is always adapted to the developmental stage of your child. This means that you should always use the oldest milk from your “milk bank” first. This ensures that your child gets the right nutrients at the right time.

Using frozen breast milk

What is the best method for freezing breast milk?

You basically have two options here. Either you fill the expressed breast milk into bottles or into breast milk bags. It’s up to you which option you choose. To help you decide, we have listed all the advantages and disadvantages here.

Breast milk bags are especially practical for space-saving storage. If you do not have a large freezer or fridge-freezer combination, you can store the bags much better.

  • Advantages:
    Space-saving storage
    Faster defrosting due to flat bags
  • Disadvantages:
    Decanting necessary
    Can be used only once

Breast milk bottles can usually be easily screwed onto the associated breast pump. This means that not a drop is lost. However, storage is not really space-saving. Make sure that the bottles are made of polyethylene.

  • Advantages:
    Only one container for pumping, storing, freezing, feeding
    Secure closure
    Easy cleaning
  • Disadvantages:
    Hard plastic bottles sometimes still contain BPA
    No space-saving storage possible
    More expensive

Especially with hard plastic bottles, make sure that they do not contain any BPA / bisphenol-A. This chemical substance is suspected of having hormonal effects.

There are also some suppliers who have glass bottles in their range. With these, the risk of harmful substances is very low. In addition, glass bottles can be cleaned very well. However, since they can burst during freezing, we recommend plastic bottles or breast milk bags.

What is the best way to store breast milk in the refrigerator?

If you keep a few things in mind, breast milk will keep for up to four days in the refrigerator.

  • It is important to refrigerate freshly expressed breast milk as soon as possible. For storage, it is best to use breast milk bags or breast milk bottles. These are pre-sterilized and free of chemicals.
  • If you already have containers of breast milk in the refrigerator, you can pour portions together if they are at the same temperature. So let fresh breast milk cool a bit in the refrigerator before mixing it.
  • It is best to put bottles or bags of breast milk in the very back of the refrigerator. There they are least affected by temperature changes. Do not put fresh breast milk in the refrigerator door, as warm air circulates too often.

What is the best way to store breast milk in the freezer?

Very similar to storage in the refrigerator, a few points must also be observed when storing breast milk in the freezer.

  • Again, freeze fresh breast milk as quickly as possible. For this purpose, exactly the same containers are suitable for storage in the refrigerator. So either breast milk bags or breast milk bottles.
  • Important. Never fill the bottles or bags completely to the top. Breast milk expands when it is frozen. Therefore, leave at least two centimeters of space to the cap.
  • For easy handling and low losses, it is best to freeze portions of between 60 and 100 milliliters. After thawing, you can mix different portions.
  • Place bottles as straight as possible. It is best to store frozen breast milk in the back of your freezer. There, the temperature fluctuates the least.

How healthy is thawed breast milk?
Fresh breast milk contains nutrients, the living cells of the mother, and growth factors. It is not for nothing that it is still considered by many scientists and midwives to be the best food for healthy babies. Temperature fluctuations change the effectiveness of the ingredients and increase the risk of contamination.
Therefore, fresh breast milk is healthier than expressed and refrigerated breast milk. Refrigerated breast milk is healthier than frozen and thawed breast milk.

Nevertheless, frozen breast milk still contains large amounts of fats, antibodies or growth factors.
Even after thawing, it is a very healthy and optimal food for your child.

Can I refreeze breast milk once it has been thawed?

No. Once thawed, breast milk should be used as soon as possible. It is best to feed your child directly with the thawed and warmed breast milk. If this is not possible, you can store thawed milk in the refrigerator for about 24 hours. Once you have warmed breast milk, you should not cool and reheat it again.
Accordingly, you should not freeze breast milk a second time. This will result in the loss of important proteins and nutrients. In addition, freezing does not kill germs and bacteria, but only slows down their spread. Thus, freezing breast milk is no guarantee of safely germ-free milk.

Do I still need to warm up thawed breast milk?

To prevent colic or stomach aches in your baby, be sure to warm frozen breast milk to the body or room temperature. Breast milk at body temperature is about 37 degrees Celsius. You should never heat the milk above 40 degrees Celsius, otherwise, important ingredients will be lost.
If you thaw frozen breast milk under running water or in a water bath, you can easily raise the water temperature so that it is comfortable for your baby.

If you thaw breast milk in the refrigerator, it is best to warm it up in a water bath or under running water. Always swirl the bottle or bag back and forth a little so that it warms up evenly. Before feeding, you should swirl the milk a little so that all the fat and water components mix again.

The fastest way is to warm up thawed breast milk using a bottle warmer. Some of these devices also have a built-in defrosting function. This allows you to heat breast milk from the refrigerator to body temperature or room temperature within a few minutes.

Do not heat breast milk in the microwave.

Then, before you feed your baby, be sure to test if the temperature is right. To do this, you can simply put a few drops of milk on the inside of your wrist. The skin is very thin here, and you can quickly tell if the milk is too hot. If the temperature is pleasantly warm, you can give it to your child.

Why does thawed breast milk smell different?

Thawed milk can actually smell different from what you are used to. This is due to the enzyme lipase. This breaks down fatty acids and is also active at cool temperatures. The soapy or vinegary smell is caused by the oxidation of the split fat particles. For this reason, the process is also called saponification of breast milk.

The splitting of the fatty acids helps the child with digestion and is therefore not a negative process.
Most children are also not bothered by the smell and drink the milk without any problems.

However, it is important that this smell of thawed breast milk is not mistaken for bad milk. If the bottle was left outside for too long or was not used up in time, germs can collect in the bottle. Opened milk bottles should be used within 2 hours. After that, you should not use the milk for feeding.

Why does thawed breast milk sometimes look different?

Basically, breast milk can take on different shades of color. Both yellowish, bluish, brownish, or even greenish milk is normal. This depends mainly on the mother’s diet and what age your child is.
The first milk also called colostrum, is very yellowish to orange. It contains everything the baby needs for the first few days. From about the tenth day, more mature milk is formed, which is whitish. The front milk is more watery and whitish than the hind milk, which has a higher fat content.

If you freeze milk, the fat may well separate from the water content. The lower part is therefore usually more transparent, while the upper part is darker.

Depending on the stage of your child’s development, breast milk contains different nutrients. This can also be a reason for how light or dark the breast milk is. If you find older breast milk, it may simply be that at the time it was slightly lower in fat than the breast milk you know now.

5 tips to help you thaw breast milk

Sometimes a mom just can not breastfeed herself. Then reaching for frozen breast milk is very helpful and prevents stress.

Did you know that front milk is more watery than hindmilk? This is because the first milliliters are meant to quench your baby’s thirst. The next sips then provide your baby with more nutrients, so the hindmilk is whiter.
But to make sure that neither thawing nor freezing is difficult, we have listed five tips that will make your life easier.
This way, the dad can also feed the baby without any problems while the mom enjoys her well-deserved break.

1. Label neatly

Breast milk has a limited shelf life, depending on where it is stored. To ensure that you always thaw the oldest breast milk, you should neatly label the frozen portions. You can either use the pumping date or the expiration date. The main thing is that it is always constant.

For breast milk bottles, you can use self-adhesive stickers on which you write the date. Breast milk pouches always have a field at the top, which you can easily write on with a sharpie.

In addition to the date, it can also be useful to write breast milk thickly on the container. You sometimes don’t know if the wrong thing will be thawed when you reach for it quickly. And once warmed, you should either feed breast milk directly or dispose of it.

2. Leave space when freezing

This means that you should not fill the containers to the top. As breast milk expands when frozen, bags or jars can burst. So leave about 1/3 empty, so you can be sure that all containers will stay intact.

Never put breast milk in freezer bags. These contain harmful substances and are not pre-sterilized.

You should also leave space to the edge of the freezer compartment. This prevents the bags or bottles from freezing or even warming up due to the defrosting functions.

3. Always take the oldest breast milk first

Breast milk is always adapted to the child. In the first one to two weeks, breast milk has a particularly high level of antibodies. In the course of breastfeeding, however, the fat content increases so that your child has enough energy to grow.
This means that you should use expressed breast milk as soon as possible. If you have a “milk bank” in the freezer, you should always use the oldest breast milk first. This will ensure that your baby does not eventually drink food that is too low in nutrients.

In addition, breast milk can be kept in the freezer for about six months. Studies show that after just three months, the fat and calorie content has decreased significantly. To keep this decrease as small as possible, always take the oldest breast milk.

4. Freeze small portions

To avoid unnecessary losses, you should only freeze small portions. Once thawed, you should not freeze breast milk again. Thawed breast milk can only be kept in the refrigerator for a maximum of 24 hours.

You know best what portion size is right for your child. We recommend freezing about 60 to 100 milliliters.

Both breast milk bottles and pouches have a measurement on the container, so you know exactly how big the portion is. If you need more, you can add warmed breast milk to an already warmed portion.

5. Mixing of portions possible

Your child drinks more than expected or only a few milliliters are collected per pumping? Then it is practical to collect breast milk and mix it into a larger portion.

However, make sure that you only mix portions with the same temperature. In this way, you prevent the storage time from shortening. Bottles that have already been stored in the freezer should not be filled with breast milk that is warm to the body. This will cause the milk to reheat and lose nutrients more quickly.

Always ensure hygienic handling. Both when pumping and transferring, cleanliness and hygiene are enormously important.

Generally, milk pumped over a 24-hour period can be collected. However, it is best to always use a new bottle for each pumping. If you always pump breast milk into the same bottle, you will warm the already cooled milk with your hands each time. When you’re done, you can let the new bottle cool a bit in the refrigerator and then add it to another chilled portion.

Additional tip.

Have you left breast milk in the fridge or outside for too long? No problem! This is no reason to throw away breast milk because it can be used as a bath additive.

Simply add a large tablespoon of breast milk to your child’s warm bathwater. The rich care moisturizes the skin and gives it a soft surface. By the way, breast milk also has the same effect on inflamed children’s buttocks. You can prevent so-called diaper rash by regularly rubbing a little breast milk into your child’s buttocks.

Did you know that breastfeeding can reduce the risk of type 2 diabetes or heart disease in mothers? In addition to short-term effects, such as a lower risk of postpartum depression, positive long-term effects on cancer or heart disease have also been found.

Breast milk can also be helpful for adults. In case of dry spots or itching, simply rub a small amount on the affected area and benefit from the natural care. Without any side effects, you can use natural cosmetics without buying expensive products.

How to Store Breastmilk. GREAT TIPS! –  Video

FAQ - Safe Storage of Expressed Breast Milk

❓ Can I store breast milk from different pumping sessions?

Milk from different pumping sessions/days may be combined in one container – use the date of the first milk expressed. Avoid adding warm milk to a container of previously refrigerated or frozen milk – cool the new milk before combining. Breastmilk is not spoiled unless it smells really bad or tastes sour.

❓ Can I refrigerate a bottle of breastmilk?

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.

❓ What do you do with leftover breast milk in a bottle?

The same goes for breast milk. If after feeding your baby, you’re left with half or a quarter of a bottle, put it in the fridge and offer it again at the next feeding, but that’s it. “Used” breast milk can become contaminated, since bacteria from the baby’s mouth can get into the bottle while your baby sucks.

Meet Our Team

BabyAmo is a magazine of top products for infants and babies. We writing best reviews and do our best for people who want to save their time and energy while searching for an ideal product regardless of the budget they have.







BabyAmo Review Journal

Learn all Things to Buy for Your Babies

Test Products

We test the products we choose to see their features in action

Best Reviews

We detail write in-detail descriptions of the items’ features

Buying Guide

We combine all our findings to help you pick the product

Editors choice: 4,9/5

Leave a Reply