Collapsible content

How do I pump and store breastmilk?

Properly pumping and storing breast milk can help ensure that the milk is safe for your baby to consume and that it stays fresh for as long as possible. Here are some general guidelines for pumping and storing breast milk. For more detailed and current information, visit

  1. Cleanliness: Before pumping, make sure that your hands and any equipment that will come into contact with the milk are clean. Wash them with hot, soapy water and dry them thoroughly.
  2. Pumping: When you're ready to pump, position the flanges (the plastic or silicone cups that go over your nipples) of the breast pump correctly and make sure that the vacuum is not too strong or too weak. Experiment with the different settings to find what works best for you.
  3. Storing: After pumping, transfer the milk to clean and sterile containers such as BPA-free plastic bags. Leave enough room in the container to allow for expansion as the milk freezes.
  4. Labeling: Label the containers with the date and time that the milk was pumped, so you can keep track of how fresh it is.
  5. Refrigeration: Freshly pumped milk can be stored in the refrigerator for up to 5 days.
  6. Freezing: Milk can also be stored in a freezer, either a stand-alone freezer or the freezer compartment of a refrigerator. Breastmilk can be stored for up to 6-12 regardless of the type of freezer it is stored in. For best quality, it should be used within 6-12 months as it begins to lose nutritional value over time.
  7. Thawing: When you're ready to use the frozen milk, thaw it in the refrigerator or by running it under warm water. Never thaw frozen milk in a microwave or on a stovetop.

It's important to consult with a lactation consultant if you have any concerns or questions about pumping and storing your breast milk.

Is it better to freeze dry or dehydrate breast milk?

Dehydrating and freeze-drying are two methods of removing moisture from food, but they differ in the way in which they achieve this end and in the final product they produce.

Dehydrating, involves removing moisture from food by exposing it to hot, dry air. This is typically done using an oven or a dehydrator machine, which blows hot air over the food to evaporate the water. The temperature used in dehydrating varies depending on the food being dried, but generally, it is between 120°F to 140°F (50°C to 60°C).

Conversely, freeze-drying (aka lyophilization), is a more complex process that involves freezing the food and then removing the moisture by sublimation. The food is first frozen at very low temperatures, usually around -40°F to -50°F (-40°C to -46°C). Then, the food is placed in a vacuum chamber and the pressure is reduced, causing the frozen water in the food to turn directly into vapor without ever passing through the liquid phase. This means your milk is never thawed in the process! And, unlike dehydrating, freeze-drying relies on very low heat which makes it the ideal preservation technique for living foods like human milk which can be significantly damaged by high heat. Freeze-drying is typically done using specialized equipment and can take several days to complete. 

The final product produced by freeze-drying is usually of higher quality than dehydrated food. This is because freeze-drying preserves more of the food's original texture, flavor, and nutritional content. Additionally, freeze-dried food can be rehydrated quickly and easily, making it a popular choice for busy families on the go!

How does freeze-drying affect lipase?

Lipase is an enzyme found in all milk that helps to break down fats so that they can be easily digested by the baby. It is produced by the mammary glands and is essential for the absorption of nutrients, particularly the fat-soluble vitamins A, D, E, and K and it also provides immunological effects. Sometimes, when frozen breastmilk has high lipase activity, it can acquire an unpleasant, soapy taste or smell and some babies may refuse the previously frozen milk. Up until recently, it was believed that some people had excessive lipase in their milk, but new research has revealed that it is actually excess lipase *activity* responsible for the changes in odor and palatability. Thankfully, the milk is still safe to consume! 

Freeze-drying can’t reverse the effects of lipase, but it does prevent them from getting worse, because it stops all enzymatic activity until the milk is rehydrated and ready to be eaten (processes that would have otherwise continued in frozen milk). The rate at which lipase activity occurs varies from person to person, so we recommend freeze-drying as soon as possible in order to minimize its potential implications.

How should I store my rehydrated freeze-dried breastmilk?

Once rehydrated, Mothership Milk should be treated and handled with the same care as previously frozen milk. It can be stored at room temperature for up to 2 hours or 1 hour from when baby’s mouth comes into contact with he bottle (as bacteria from baby’s saliva can be introduced). If you do not use the milk right away, place it in the fridge immediately for up to 24 hours and then discard. Rehydrated milk should not be refrozen or microwaved. 

How long does freeze dried milk last?

According to the USDA, sealed freeze-dried milk is considered best before 3 years when stored in a cool, dark, dry space. Do not store in a garage or vehicle.

Once rehydrated, freeze-dried milk should be treated with the same care as previously frozen breastmilk.

How do I know I am getting my own milk back?

As soon as your milk arrives at our facility, each individual bag of your milk will be labeled with your name, date and order number.

We handle only one client’s milk at time and each batch is processed individually in its own freeze-dryer.

Mothership Milk has also developed its own customized app to guarantee chain of custody at every step of the process.

Why do you pool my milk?

Your milk is removed from its storage bags and combined because pooling provides a more even spread of goodness and nutrients across all bags. Further, because we defer to evidence based research to guide our protocols, milk banks that currently distribute freeze dried milk also employ this method, so we do, too.

If you would prefer to have your milk separated into different batches instead of combined, please reach out to us at and we will try our best to accommodate your customized request.

How long does it take to get my breast milk back?

If you ship us your milk, anticipate up to 3 weeks from when your milk arrives at our facility to be processed and returned to you. If you need your milk freeze dried like yesterday, select "expedited shipping" at checkout to reduce your order processing time to about 10 business days.

If you drop your milk off at our facility in Southwest Michigan, please anticipate approximately a 7-10 business day turnaround.

What’s an oxygen absorber?

An oxygen absorber is like a sponge that chemically traps available oxygen from the surrounding environment without the use of chemicals or additives.

Oxygen absorbers contain an iron powder formulation that becomes iron oxide in the presence of oxygen, chemically removing the oxygen from the environment at a molecular level. They are non-toxic and categorized by the FDA as GRAS (Generally Recognized As Safe).

Oxygen absorbers are added to each packet of Mothership Milk as added protective measure to extend shelf-life. Simply remove and discard before use.

How much milk will I get back?

You will get the same amount of milk back as you sent in. For example, if you sent in 200 oz, you will be able to reconstitute your freeze-dried milk powder into 200 oz of fresh milk.

How much milk does one packet make?

One packet of Single-serving Mothership Milk contains enough powder to rehydrate to just over 4 fluid ounces of milk (this will vary slightly depending your milk’s unique water content, but we will let you know the correct ratio to use to rehydrate it back to its original consistency).

One bag of Mothership Milk Multi-serve contains enough powder to rehydrate 30-50 fluid ounces of breastmilk. Accurately using the chart provided will rehydrate your milk to a 87% water content.

Besides bottles, how can I use my Mothership Milk?

Your freeze-dried breastmilk powder can be used in a number of ways. It can be rehydrated with water to make a bottle, mixed into foods for to pack an extra nutritional punch or you can even coat difficult to grasp foods like avocado in the powder to make them easier for baby to hold as they’re perfecting their pincer grasp.

I’m not sure how much milk I have frozen. Is there an easy way to add it all up?

Yes! Take all of your frozen milk and put it in a plastic bag. Place the bag on a scale (a bathroom or kitchen scale will do!).

Divide the total weight by 6.5 lbs and multiply by 100 oz. For example, 10 lbs of breastmilk/6.5 lbs X 100 oz = 154 oz (rounded up).

How can I keep my reconstituted milk from clumping?

In order to maintain the bioavailability of your breastmilk, we do not homogenize it before freeze-drying. This means that sometimes the fats in the milk can take a bit longer to rehydrate which can cause clumping or a grainy appearance. To negate this, we suggest rehydrating with warmer water, using a glass bottle (as the fats will more readily stick to plastic or silicone bottles), shaking the bottle more vigorously (don’t worry, thorough shaking will not damage proteins in the milk!) and running the bottle under warm water (being careful not to accidentally add more water to the bottle in the process). That said, fat separation is completely normal!

What’s my personalized conversion rate?

Your “personalized conversion rate” tells you exactly how much water to add to one packet of Single-serve freeze-dried breastmilk powder to make just over a 4 oz bottle.

What’s the deal with the packaging?

Our packets are made from FDA approved, food-grade storage bags that are virtually impervious to oxygen. They bags are hermetically sealed and an oxygen absorber is used to further reduce oxygen levels within the packet and protect the food from spoilage.

How does pricing work?

There is no minimum quantity of breastmilk that can be freeze-dried. Rather, our pricing structure is based on a maximum number of ounces that can be processed at a time. This means that the more milk you freeze-dry, the less it will cost per ounce.

For example, if you would like to have 75 oz of breastmilk freeze-dried, you would select “Up to 100 oz” as your service selection. Mothership Milk charges a flat fee and does does not pro-rate. If you send in more milk than you originally signed up for, Mothership Milk will contact you to determine if you would like a) to be charged for the extra milk or b) have the extra milk sent back to you (additional shipping fees will apply).

How does shipping work?

If you're unable to drop off your milk at our facility in Plainwell, Michigan, a flat shipping rate will be added at checkout that includes shipping in 3 directions:

  1. We send you a Shipping Kit with everything you will need to send us your milk and keep it frozen in transit (cooler, gel packs, prepaid shipping label) via ground shipping.
  2. You pack and ship us your frozen milk with overnight service.
  3. We freeze-dry your breastmilk and send it back to you via ground.

You must ship us your milk on MONDAY, TUESDAY or WEDNESDAY. In the event of a shipping delay, it is much easier for the carrier to locate and get your milk to us in a timely matter on those days. Please try and drop your milk off to UPS as close to their "Air Shipment Cutoff Time" as possible.

What if my milk is thawed in transit?

Your frozen milk should be shipped on Monday, Tuesday or Wednesday, NOT on Thursday or Friday. In the event of a delay, shipping earlier in the week provides more time for it to be found (whereas service is limited on the weekends and your stash runs a greater risk of being thawed). Please pack your shipment just before dropping off at your UPS location. Plan to drop your frozen milk off as close to their “Last Shipment of the Day” cut-off time (listed on your UPS store’s Hours of Operation).

Mothership Milk will not be held responsible for any loss or damages incurred to your parcel in transit. If your milk arrives at our facility thawed, you will be notified immediately and refunded for the cost of freeze-drying minus shipping costs.

What kind of breastmilk storage bags do you accept?

We accept all FDA approved breastmilk storage bags. Alternative storage containers can also be accepted (such as reusable silicone bags), but we need to be able to remove milk from its packing while still frozen.

If your breastmilk storage bag is an irregular shape (wearable pump style bags are fine) or has a screw-top lid (such as a Kiinde bag), please contact us before ordering because these bags may not fit properly in our standard-sized shipping coolers at

Can I combine my order with a friend’s?

No, because each client’s milk is freeze-dried in its own individual machine to prevent cross-contamination.

Can you separate my milk into different batches?

Yes, this is definitely possible! We have been able to accommodate a large number of our clients’ requests, such as separating their morning from evening milk. Please email and we will try our very best to make it happen!

How much water do I need to rehydrate freeze dried breast milk?

That depends on how much water your milk contained before it was freeze dried. Don’t worry, we will handle all of the math and provide you with a personalized conversation rate to rehydrate your Single-serve Mothership Milk back to its original consistency. This information can be on the back of each packet.

Multi-serve orders will have a 87% water to powder conversion rate listed on the bags.

At what temperature do you freeze dry breast milk?

Below body temperature to help prevent protein denaturation and preserve antibodies.