Handling and storing breast milk

Handling and storing breastmilk

Breastmilk is a fascinating substance.(benefits of breastfeeding) It’s great to know that it provides not only all the nutrients that your baby needs, but it’s also got specific antibacterial properties that helps it to stay fresh – and it limits the growth of bacteria – and in this respect it has to be distinguished from formula which isn’t a living substance, and doesn’t have any of those antibacterial properties.

So the guidelines for storing breast milk compared with formula are very different. So if you are expressing your breast milk by hand or by pump, it’s still really important that you gain knowledge around how to handle that milk and to store it really safely.

So one of the first things to remember is to always wash your hands before you express your milk – this means that you’re going to limit the bacteria, the growth of that bacteria in your milk because of this very simple measure.

frozen breast milk in storage bags and baby bottle with fresh expressed milkSo you may wonder what kind of containers you’re going to use to express your milk into – and many women have tried to express milk into a bottle for instance, and found that that was quite difficult because milk comes out from all directions, and it is difficult to catch, so many women will use a wide- mouthed jug or bowl, something like that, to catch the milk – but that container can be either sterilised or put into your dishwasher and washed that way, really safely, before collecting that milk. You may also want to use hot soapy water to wash that container beforehand, and then to rinse it and let it air dry before you collect your milk.

I must stress, however, that once you’ve collected your milk it is then really important to store that milk either in the fridge or the freezer in a sterilised container. You may wish to consider using leak-proof food storage containers or plastic bottles that have got a really good well fitting tops, maybe that you use freezer bags that are specially made for breastmilk – but always remember to label and date the milk so that you can use the oldest milk first.

How you store your breastmilk will depend on how soon you want to use it. Now if you want to use your milk immediately, you can literally express your milk and leave it at room temperature for up to six hours. There is some literature which says up to eight hours, but we tend to say six hours (erring on the side of caution), and that milk can be given fresh to your baby.

Now if you want to keep your milk for a few days, it’s far better to refrigerate your milk than to freeze it. Freezing will destroy some of the anti-infective properties but not all, and it’s still good, BUT refrigeration is a far better option.

Your breast milk can be kept at the back of a fridge if your fridge is 0 -4 degrees (centigrade) or below. It can be kept for up to five days and still be given fresh to your baby. Please bear in mind though that if the temperature goes above four degrees, then you’ll have a six hour window to be able to use your breastmilk for your baby before you have to throw it away.

And if your fridge is actually five to 10 degrees, (temperature), then you should only keep that breastmilk for about three days. I think it’s also really useful to know that if you are going back to work for instance and you didn’t have access to a refrigerator or you are out and about with your baby, and want to take that breastmilk, you can store it in a cool bag or box that has deep frozen ice packs in it, and those would have to be changed every 24 hours – but it does give you flexibility.

And I did come across a lady who was hospitalised and she wasn’t able to use the fridges in the hospital for whatever reason. She was then able to bring one of these cool bags into the hospital and that helped – and it’s great to know that your breastmilk can be stored in a freezer that’s -18 degrees and be kept for up to 6 months and given to your baby – and although freezing will destroy some of the properties in breastmilk that help to fight infection, it’s still the healthiest choice for your baby over formula.

So if you are freezing your milk it’s always best to express, and then to store it in the freezer straightaway – and always remember to leave a little gap at the top of the bottle or the freezer bag just for that expansion of the milk when it’s frozen.

And I have known some breastfeeding moms who’ve stored breast milk in ice cube trays, just very small amounts in a sealed container, or one with a lid, so that they can use that very small amount of breastmilk to mix with foods, for instance.

Another really handy tip is that if your expressing your milk you can add to the same batch over 24 hours. So, for instance, if you only get a small amount here and a small amount there, if you chill that milk for maybe an hour, you can add it to an already chilled amount that’s in the fridge. Keep adding it over 24 hours.baby bottle with fresh expresed breast milk, frozen breastmilk in storage bags and soft toy pink teddy bear,

It’s a good rule of thumb to store your milk in 60 to a 120 ml amounts – so really that’s two to four ounce amounts – and that is just that when babies feed at the breast, they tend to take round about that per feed, and so storing your milk in smaller amounts like that means that there’ll be less wastage.

And sometimes I do get concerned mothers wondering why the milk appears to be separating into two distinct parts, a creamier part and a milk part. This is completely normal and it’s important that you just swirl that milk a little bit and then give it to your baby – it’s absolutely fine.

Sometimes I’m asked about the smell or the taste of the milk where mothers say that the milk tastes or smells a little bit soapy. This actually is related to the breakdown of fats within the milk and it is safe for the baby to drink.

So is it possible for your milk to go off? The truth is that it CAN go off – if you felt that it smelt rancid or tasted very like cows milk when it goes off, then it’s not to be given to you baby.

Very occasionally a breastfeeding woman will tell me that even when she stored her milk for a VERY short period of time, and EVERY time she does this the milk really smells quite rancid – and this can be due to an overactive amount of the lipase enzyme breaking down milk fats, and this can be a problem. If this is true for you then there is a way that you can try to deactivate that enzyme. This entails expressing your milk and then immediately heating it up to the point where there is bubbles around the edge, but not boiling as such, then immediately cooling it and freezing it, and this will deactivate that enzyme.

Another important point that I wish to make is that if you or your baby are being treated for a thrush infection then it’s great that you carry on breastfeeding and you can express as well during that time, during the treatment time. It may be that you freeze milk and you refrigerate it and that expressed milk can be given to your baby WHILE your baby is being TREATED and yourself, BUT because that refrigeration or freezing doesn’t kill the yeast, then once that treatment has finished, you must discard the expressed milk.

If you have refrigerated your milk and you now wish to give it to your baby, you can do one of a number of options. One is to offer your baby that milk straight from the fridge without warming it up at all – and many babies will take milk like that – doesn’t always have to be heated up. Secondly you may wish to warm it by running it under a nice warm tap, and just gradually warming that milk up, getting it to room temperature – and thirdly, you may wish to warm it up by placing that container in a bowl filled with hot water from the kettle or the tap, just to gradually warm it up that way.

But it’s really important that you are never tempted to heat the milk up in a microwave, either to defrost it, or to heat it up, because microwaves can be dangerous in that hot spots can occur, and that is a safety issue.

If you have frozen milk which you wish to defrost it’s far better to let it gradually defrost in your fridge overnight perhaps, and then once it’s thawed you can leave it in your fridge for up to 24 hours. But you must give it to your baby within that time. If however you were in a hurry, you may need to defrost that quite quickly so in that scenario you can run it under the tap under cool water, and then warm running water, or you may wish to stand it in a bowl of hot water and defrost a little bit faster that way.

Sometimes I get ask questions relating to breastmilk storage for which we don’t really have real evidence. One of those questions is ‘can I give my breast milk to my baby and if my baby doesn’t finish it all, can that milk then be given at a later date?’

My own gut feeling on that, based on what we know about breast milk would suggest that it could be refrigerated again and maybe given within one to two hours, and that would be erring on the side of caution. I have seen certain evidences of people’s opinions on this that suggest it could be left a bit longer, but until we have that reliable research it’s always best to err on the side of caution.

And finally I just want to mention that the storage guidelines that appear at the end of this video are related to healthy full term babies. If your baby has been born prematurely for instance or has been poorly then it’s very important that you seek the guidelines around storage with your health care provider.

Review dates, references & further resources

Review Dates

Version 1.1 published in March 2019. Next review date: Jan 2022


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