How to build an amazing breast milk freezer stash

There are many reasons why you might want to build up a freezer stash of breast milk. 

Whether you’re going to be separated from your baby regularly, or for a brief spell, it’s great that you have the option to continue giving your baby breast milk.

One of the best things about expressed milk is how well it freezes. Expressed milk will keep in the freezer for up to six months, so if you can build up a decent stash then you can be all set for some time!

Many mothers find that having a freezer stash helps them to continue breastfeeding their babies for longer, or gives them a much-needed break when you need it. 

If you’re already worried about your milk supply, or struggling for time every day, then it might feel more than a little daunting to think about filling your freezer with breast milk. 

You might also be wondering how you can build up a supply if you’re already exclusively pumping for your baby. 

It’s important to note that having a stash doesn’t mean every drawer in your fridge is full! You might just need a rolling stash of around 25oz, which is roughly what your baby will need for an entire day. 

Building a freezer stash is about striking a balance between what you need and what you’re physically able to/have time to produce. 

Whatever your worries about building up a breast milk stash, this post will answer them. 

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Why might you need to stockpile breast milk in your freezer 

Whatever the reason you want to stockpile your breast milk, first of all let’s make it clear that it’s totally possible to do!

The reasons you may want to get a decent stash of breast milk in your freezer include: 

  • You’re returning to work but want your baby to continue having your breast milk. 
  • You want to stop breastfeeding for a trip or because you’re ready to quit, but you want your baby to continue receiving breast milk for a while longer. 
  • You want a back-up supply for emergencies. 
  • You want to donate your breast milk. There are breast milk banks all over the world that provide donated milk to babies who have been born prematurely and their mothers are struggling to produce enough milk as well as little ones in other difficult situations. Research your local milk bank to find out what their requirements are. Most run a collection service. 

Of these reasons, the most common issues that may lead mamas to build up a back-up supply is certainly the work issue. 

It makes me so sad to see that ladies in America do not get as much time off work after having a baby as we do in the UK. 

In the UK our jobs are protected for a year, and although it varies depending on where you work, you receive a decent amount of maternity pay during that time to tide you over. 

However, if you are self-employed or want to return to your career after six weeks with your baby, which is of course totally fine, then building up a stockpile may also be a good compromise if you want your baby to continue receiving breast milk. 

How big should your breast milk stash be?

Pumping breast milk for a freezer stash

It may shock you just how much breast milk you can actually pump once you get into a routine. 

When I was exclusively pumping for my baby I was pumping five times a day for around 40 minutes a time. I had a stash of two litres at one stage. I felt proud, but ultimately I cut back on my number of pumps because I didn’t need a huge amount as back-up. 

The trouble with creating an enormous horde of breast milk is that you may never actually make a dent in it!

The size of your milk stash really depends on how long you will be feeding your baby with the stash, whether you are still feeding your baby from the breast as well and whether you are continuing to express and store your milk while using the stash. 

It may be that you are going to quit breastfeeding to back to work, but want your baby to have enough breast milk to feed them.

Whatever your situation, you just need to do your math. 

Figure out how many feeds you need to stock up for, then calculate how much your baby will need to drink each day. As a rough guide, babies will take around 25oz per day. Every baby is different, so you may want to assume baby will need 30oz a day just to be safe. Divide this by the number of feeds your baby has per day, and this will give you the amount per feed. 

For most babies this is anything between 4oz-8oz per feed. 

Figure out how many feeds you will be missing per week, and multiply it by the amount per feed your baby takes on average and this will give you an idea of how much milk you need per week. 

As part of this, you also need to take into account that you may still be feeding your baby yourself in the mornings and evenings. This is a good idea, as putting your baby to the breast as much as possible will help to boost your supply. 

While modern breast pumps are great, nothing beats your baby for stimulating your milk supply. 

So let’s look at an example of how much you may need to pump: 

  • Say your baby drinks 6oz per feed. 
  • You will be leaving your baby between 9am and 5pm three days per week. 
  • This means your baby will be away from you for three feeds per day totalling 18oz three times a week. Multiply 18oz by three, which gets you 54oz. So you need to pump 54oz milk per week.

Now this might be at the high end of the spectrum of what your baby may eat. You may need to adjust this slightly if your baby only takes 5oz per feed, but it gives you an idea of how to work out what you need. 

Of course you may be pumping so you can quit altogether, but this puts a lot of pressure on you. 

For example, if you want to pump enough breast milk for your baby to last six months you will need around 4,500oz of breast milk. 

This is assuming that you are planning to stop feeding your baby from your breast altogether! 

The most likely option is that you want to combine breastfeeding your baby along with pumping and using the freezer stash. 

Remember that a baby who is weaning will start taking fewer feeds. You can of course use breast milk in your cooking for your baby, for example mix it with baby rice, pop it on cereals or use it to make popsicles. 

Do not panic about your stash

Now the figures above may have completely freaked you out!

It’s important to take a deep breath and remember it’s all going to be OK. 

You are not super human and you may not have the time or energy to pump dozens of ounces of milk in just a short space of time. 

Building a breast milk stash


When setting your goal for how much you want to pump and store, it’s important to be realistic. 

How much can you reasonably pump in a day? If it is not going to be enough to hit the target amount you need, then consider supplementing with formula. There’s absolutely nothing wrong with doing that, and your baby will still get all of the benefits of breastfeeding when combination feeding. 

If you can pump even just 2oz per day, this can soon add up! Just 2oz a day for a month is 60oz. 

Set attainable goals and do not let this issue consume you too much. 

Get the kit together 

Make your life easier by getting together the right kit for pumping and storing your breast milk. 

At the top of this list is an amazing electric breast pump, the best one that you can afford to buy, along with storage bags that will keep the milk secure in your freezer. 

I had never heard of the Haakaa breast pump when I had my two babies. Wow I wish I had one when I was pumping and feeding!


This handy manual pump can be placed over your breast one feeding from the other boob, and collects the milk from the letdown! This would have been so handy for me as my letdown was crazy strong when I started feeding. I’m sure I lost at least an ounce at every feed that just soaked into my other breast pad. 

The key items you need for building your milk stash are: 

  • A good pump. If you can stretch to it get a double pump as this will save you time when it comes to pumping. 
  • A Haakaa pump. This can collect milk when you are nursing your baby. Even if you only get a tiny amount it all adds up when you put it together!
  • Breast milk storage. Bags that you can store upright are best as they use up less space than bottles. Make sure they have a good seal on them, as you don’t want to be crying over spilt milk! Most bags store around 6oz of milk. 
  • Steriliser. If you have a dishwasher you can wash your pump parts and bottles but this will not sterilise them. You can get a microwave steriliser, an electric standalone steriliser or a cold water steriliser which works with what is basically a bucket of cold water and steriliser tablets. 

Use the breast pump regularly 

If you are going to build up a decent breast milk supply then you need to find a regular schedule for pumping. 

How often you pump does depend on how much you get in a single session. 

It also depends on how often you are away from your baby. You should aim to pump at every feed time that you are away from your baby to maintain supply for usual feeds when you are back with your little one. 


To build up a good stash, it’s essential to get a pumping session in in the morning, as this is when most mamas find they pump the most milk.

If you are continuing to breastfeed your baby while building up a milk stash, then the best times to pump are going to be: 

  • First thing in the morning (try pumping right after your baby has fed).
  • When baby is asleep. Yep, that includes in the evening. 

Many mothers find their most productive pumping sessions are overnight in the early hours of the morning. If you are up with your baby at this time anyway, it’s worth considering having a pumping session at this time. 


But as stressed above, do not compromise your own wellbeing above building this freezer stash!

If your best time to pump is during the daytime when baby is distracted by play (you could put them on a play mat and sit next to them while you pump) or napping then do that. 

Some mothers find it easy to pump on one side, while feeding the baby on the other side. This is made easier if you have a special bra that holds your pump in place.

I personally could never get on with this method, and my baby always found any noise during feeds a distraction.

My preferred pumping times were first thing in the morning and right before I went to bed as these were just the most convenient. Any other time I managed to during the day was a big bonus!

Remember to pump from both sides for the same amount of time at every pump.

A good length of time to pump at each session is around 30 minutes, so that would be 15 minutes on each breast.

Boost your milk supply

Give yourself the best chance of producing lots of milk for your breast pump by taking good care of yourself. 

To boost your milk supply you can drink tons of water, eat a healthy diet and get as much rest as possible. 

Other tips for increasing your milk supply include: 

  • Holding a photo of your baby when pumping. 
  • Increasing the number of times you pump. 
  • Try power pumping sessions. This is where you pump for 10 minutes on and then 10 minutes off for an hour a couple of times a day. 
  • Massage your breasts gently during pumping. 

There are lots more tips for boosting your milk supply here. 

Organise your milk 

Say you are pumping regularly throughout the day and at each session you get a couple of oz. You don’t want to store all of those separately!


You can combine milk from different pumping sessions, and even different days, together in one storage bag. 


You will need to label the bag with the date for the first pumping session, so that bag will remain safe to consume for six months from the day the first batch of milk was expressed. 

Breast milk storage bags vary when it comes to size, but most will hold around five to six oz. 

If your baby only takes 4oz at a feed then you may want to put this much in each bag, so that it’s a full feed and none will be wasted. 

There are more tips on storing milk here. 

Label your milk 

When putting your milk away in the freezer, it’s important to be sure when the milk was pumped. 

Breast milk can only be kept safely in the freezer for up to six months. After this it needs to be discarded for safety. 

It’s worth noting as well that studies have shown your breast milk actually adapts and changes as your baby grows older. If there is a virus going round for example, a mother can pass on immunity through her breast milk.

For this reason you probably don’t want to feeding your baby from a stash that’s too old. It’s not to say that you can’t if you need to, but it’s worth noting that your breasts produce milk that’s ideal for your baby at their current age and the environment they are in.

You can buy labels that stick onto the front of breast milk pouches, or get a black marker pen and write directly onto the pouches. 

Write down the date your expressed or a use by date, whichever is the easiest system for you to use. 

Organise your milk in a freezer drawer, with the oldest milk towards the front so that you use that first. 

Be careful not to overpump 

When I was exclusively pumping for my baby I would occasionally get a little overzealous with the pump. 


At one stage I was pumping seven times a day. The trouble with this is that if you cannot sustain it every day, then your boobs are going to become engorged. 


Your breast milk production works on a supply and demand basis. 


You or your baby drains milk from the breast and as a result, the breasts make more milk. If you pump seven times three days in a row, then drop it down to just four times the following few days, you are likely to become engorged. 


Engorgement can lead to discomfort, pain, blocked milk ducts and infection known as mastitis. 

Try to set a pumping schedule that works for you. If you need to drop pumps at any stage, then do so gradually, dropping one pump at a time rather than all at once. 


You may also need to hand express to take the edge off any discomfort while your breasts adjust to the change. 

If you do get a clogged milk duct, here are some tips to unblock it fast!

Don’t waste time washing up 

Did you know that you do not need to wash your pump after every single pumping session?

Instead you can just pop the parts into a clean food storage bag and stick them into the fridge until your next pumping session. This way you only need to wash it up once at the end of the day!

If you are planning to build up a large stash of milk in the freezer then you will be pumping very frequently. 

In this case I thoroughly recommend getting spare pump parts. 

Using your expressed breast milk 

Once your breast milk has been thoroughly defrosted, it can be stored for up to 24 hours in the fridge before it needs to be discarded. It can be left out of the fridge for two hours before it needs to be discarded. 

If you are transporting the breast milk to a daycare facility then defrost it overnight, then pop it into a cool bag with some ice bricks to keep it cold on the journey. Transfer to the daycare’s fridge as soon as you get there. 

Conclusion: Building up your breast milk stash

Hopefully these tips have given you a great idea on how to get started with building your freezer stash of breast milk.

The most important things to remember are self-care to make sure your supply is at its best and to set a goal so that you know exactly how much milk you need.

If you do want to build a stash, however small, it’s never too early to start! In fact the sooner the start, the less you will have to pump every day in order to meet your goal.

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