How to build a stash of breastmilk

Are you breastfeeding and nervous about heading back to work? Here is everything you need to know about how to build a freezer stash for work – how to pump extra milk, how to store it, and how to use the frozen breastmilk when you need it.

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Why Do You Need a Freezer Stash?

Many moms like to have a small stash of breastmilk for when they need to be away from their baby. This can be for a date night, for a medical procedure, or for going back to work.

How you go about starting your freezer stash will be different depending on whether you’re an exclusively pumping mom or a nursing mom. (Most of my readers are exclusive pumpers, but many are nursing and pumping moms, so I wanted to cover both!)

Exclusive Pumpers

If you’re exclusively pumping, this is pretty easy – you’re already pumping, so you just want to take whatever extra milk you have and store it in the freezer (more on how to do that in the next section).

What if you don’t have any extra?

If you’re making less or about the same as what your baby eats, building a freezer stash can be challenging. A few things that you can do are:

• Try to increase your milk supply (some ideas, in the order that I would try them, here)
• Add some (additional) formula feedings to what your baby is eating now, in order to be able to store more for later

Why feed more formula now to store breastmilk for later?

Some moms prefer to stretch the breastmilk that they have out over a longer period of time. For example, you may prefer to feed half breastmilk and half formula for six months instead of mostly breastmilk and a little formula for three months followed by all formula for three months. Or you may want to have baby have half breastmilk and half formula on the first day of childcare instead of all formula.

You can do it either way – I don’t know of any research that says one is better than the other.

Nursing Moms

If you’re a nursing mom, you may not be pumping much or at all yet. What you will want to do is start pumping once or twice a day, in order to start to stash a little extra milk.

How Often Should You Pump?

Aim for about 1-2 sessions per day.

You want to pump often enough for your body to get used to the pump and for you to build a freezer stash, but not so much that you get oversupply. Oversupply in nursing moms can cause issues with forceful letdown and foremilk/hindmilk imbalance.

How Long Should Your Pumping Sessions Be?

About 15-20 minutes should be fine. You want to get through about 1-2 letdowns, but again, you don’t want to overdo it.

When Is the Best Time to Pump?

There is no absolute, evidence-based answer to this, but I would say the best time is when you’re likely to have the most extra milk (so early evening when your baby is cluster feeding on and off the breast trying to get another letdown is probably not the best time).

My routine with the two babies that I nursed was to pump once per day when I was on maternity leave, about 30 minutes after baby’s first nursing session of that day.

(Note: By “of the day,” I mean the first session when it was light out and I was drinking coffee, not the first session after midnight.)

That gave me enough time to put the baby down for a nap after she ate, get something to eat myself, and then sit down to pump.

However, the best time for you might be different depending on your life. Try playing around with different times and see what works best for you – both for your routine and your milk supply.

More on how to time pumping sessions here.

What Do You Do with the Milk After You Pump It?

After you pump the milk for your freezer stash, you’ll want to store it in a breast milk freezer bag. (Here are some reviews of different brands.)

How much milk should go in each bag? There is no one answer for this – different things work for different people. Some people like to freeze the amount that a baby is currently eating; others like to freeze small amounts to ensure no milk is wasted.

Oversuppliers – moms that have a lot of milk – might prefer to fill breast milk bags as much as possible in order to save money on them. Try different things and see what works best for you.

Once you put the milk in the freezer bag, you want to freeze it flat (you can put it on a cookie sheet or in a takeout container – anything flat will work). Then you can store the frozen breastmilk bricks in a gallon-sized zip top bag or in a box. You can see ideas and pictures of how this should look here and in the story below:

Another option is to freeze your milk in a tray like the Ceres Chill Milkstache, so you can just grab the number of cubes that you need for each bottle.

Breastmilk can be stored for up to 12 months in the freezer.

How Much of a Stash Do You Need?

All that you really need is enough milk to send with your baby on the first day that you’ll be at work and they will be in childcare.

Having extra is always great, of course! But that would be the goal that I would aim for.

How much will your baby need on the first day of daycare? I generally sent four 4oz bottles of breastmilk with my 3 month olds to daycare, and sometimes got one of the bottles back. (Meaning they would take between 12-16oz in the nine hours that they were there.)

However, my babies were big eaters, and yours might need less or more – try testing out giving your baby a bottle and see what they take during a feeding to get an idea of what your baby will need.

How Do You Use the Stash That You Have Frozen?

When you’re ready to use your stash for the first day of work, you’ll want to thaw out enough milk to prep the bottles for the day. (Note that at some daycare facilities, you can bring frozen milk and they will thaw it for you, so you might want to check with your childcare provider before prepping the bottles.)

To thaw the milk for prepping bottles, you can either take the milk out of the freezer and put it in the fridge to defrost slowly, or you can put it in cold water to thaw. It will take about 12 hours to defrost in the fridge, and maybe 10-20 minutes in cold water.

I have a whole post on how to defrost breastmilk without wasting any that you can read here.

Hopefully this helps you understand how to build a freezer stash for work! Let us know if you have any questions or additional tips in the comments.

How long does it take to build a breastmilk stash?

What is a good stockpile of breast milk?

How often should I pump to build stash?