Can You Refrigerate Breastmilk? Your Guide to Clean and Safe Storage

While your baby is on a full-time breastmilk diet, you need supply to be on hand at all times. You may not always be physically there. So you have to be able to store milk in sufficient quantity.

We all know that our regular cow’s milk must be kept in the fridge or it will go bad. The fact that you have been milked is where the similarities end in the production phase. There is no processing of your natural product and an important question to answer is whether you can store breastmilk in the fridge, and for how long.

Breast milk is a wonder product of nature. It is packed enzymes, probiotics, antioxidants, and nutrients. It is important that you are able to retain as much of the nutrition as possible if you are not able to deliver the product to a latched baby. 

I am going to stop calling it product now… But we do have to treat it as such for us to be able to store our supplies safely.

How to Safely Store the Milk

We will assume that the extraction of the milk is taken care of. If you are undecided on which breast pump may be for you then check out our article on exclusive pumping here.

1. Wash your hands

Before pumping or expressing your milk, you need to make sure that your hands are clean.  Just remember to wash your hands with soap and water before starting the process. 

You can’t be overly cautious here. Your hands are exposed to all sorts of germs and bacteria as you go about your day. Remember that anything you touch could transfer something that could be ingested by your baby.

2. Always Use Clean Containers and Equipment

All of the elements of your breast pump will need to be cleaned thoroughly with hot soapy water after each use. If you are using plastic bottles also then these should be sterilized before transferring the milk.

BPA free plastic bottles, or plastic breastmilk bags, are the best containers to use for storing your milk. You should only use containers that are specifically designed for human milk storage and not just something you have taken out of the cupboard. 

Do not mix freshly extracted milk with anything that has already been stored. Think of each time you express as a fresh run in a production line. Once it is down the line it must keep moving forward.

3. (a) Refrigerate

If you do not put the breastmilk inside the refrigerator it will spoil quickly. From the moment you express the milk you only have 6 to 8 hours to use it.

It is best to have a section in the refrigerator exclusively for breastmilk storage. This will minimize the chance of contamination. Any kind of fresh meat or other produce can be a hazard so again play it safe here.

Storing between 32 degrees and 39 degrees (0-4 degrees Celsius) will prevent any bacterial growth in the milk, and keep it safe for your baby.  

Also, remember to label each bottle or bag with the date it was extracted. This will allow you to minimize spoilage and anything that could become unsafe.

3. (b) Deep Freeze

If you have a surplus of milk in the fridge then you can place additional bottles in the freezer. Be sure to also have a dedicated area for milk storage.

Do not fill the container all the way to the top when freezing. Breast milk will expand as it freezes and being over capacity could lead to a breach in the seal of the container. If this was to happen then you should discard the milk rather than risk feeding your baby anything that may have been contaminated.

4. Expiration Dates

The milk should be consumed within 3-5 days, but will remain safe for 7-8 days at most. If you have excess supply you can place it in the freezer.

If fresh milk is frozen then the milk should remain safe for up to 12 months.

supply of expressed milk

Nutrient Retention

Being a natural product fresh is always going to be best. Just because you can store milk for 12 months before consumption, doesn’t mean that you should… and who would want to get that far ahead in their pumping schedule anyway!!

Studies have shown that when frozen, the quality of the fat, and number of calories that each feed will provide does decline over time. This is in part due to the effects of the freezing, and thawing process and is unavoidable if you need to store a supply for your baby.

You can minimize the loss of antioxidants, fats and bactericidal enzymes by consuming within a reasonable time frame after thawing and warming the milk.

Given that stored milk is likely to only make up a portion of your baby’s diet it is unlikely that these variations will have any impact on their nutrition levels at all.

Thawing Frozen Breastmilk

The Ideal Process

First, you need to move it to the refrigerator for at least 24 hours. Then you can bring it up to the right temperature by running warm water over the container, or immersing it in warm water. 

The 24 hour wait is not a rule, just best practice. So if you need it sooner you can still take the above steps until the milk defrosts.

Expect to see some changes in the color of the thawed milk. It can take on a slightly blue, yellow or brownish color. This is nothing to be concerned about as it is just some of the fat breaking down. Breastmilk is a live organism and these changes in temperature does have an effect.

You will be able to shake and stir the milk until it returns to a relatively normal consistency. 

The Correct Temperature

When feeding your baby stored breastmilk you want to simulate the natural state of the milk as much as you can. This will help your baby be receptive to it, and also make sure there is no risk of any burning sensations if it is too hot.

If the temperature exceeds 104 degrees (40 degrees Celsius) it can reduce the immunological value of the milk, and also reduce fat absorption. Considering that a standard cup of tea or coffee would be consumed closer to 140 degrees (60 Celsius), it can be easy to underestimate the real temperature of the milk.

You can retain maximum nutrition in the milk by stirring or shaking regularly in the heating process to keep an even temperature, and by aiming for a neutral lukewarm temperature to touch.

Can you Re-use the Excess?

Once the milk has been thawed it is use it or lose it time. Thawed breastmilk needs to be consumed immediately after being heated up, and to an absolute maximum of one hour afterward.

Do not re-freeze the milk.

Keep this in mind when rationing your portions at the pumping stage. Keep it to one feed only. 

You cannot refreeze breastmilk. Thawed breastmilk needs to be consumed immediately up to an hour only. It is essential that the amount of breastmilk that you will put in the container is just enough for one consumption.

pumping at work

Final Word

Mother nature is on your side with the durability of breastmilk. The shelf life is more than enough for you to manage any lifestyle challenges that may come up from work, travel or family issues.

All that we have to take care of is the human error risk to the quality of the milk. Cleanliness and a bit of organization will do the trick here. Once you get into a routine and work out your own system it will be fine.

Oh yeah, and buy a lot of ice packs in case you get stuck in traffic on the way home from the office.