How Does The Freeze-Drying Process of Breast Milk Work?

Breast milk is often considered the gold standard in infant nutrition due to its unique composition and the essential nutrients it provides to growing babies. However, for many new mothers, ensuring that their babies receive an adequate supply of breast milk can be challenging, particularly if they return to work or cannot breastfeed due to medical and personal reasons. 

This is where breast milk preservation techniques such as freeze-drying come in to help busy and struggling mothers looking for help in breast milk storage. In this article, we will introduce the benefits of the freeze-drying process of breast milk and its role in preserving the nutritional value of breast milk for babies.

But, what does it mean to freeze dry my breast milk?

Freeze-drying is a process that removes moisture from breast milk, resulting in a lightweight and shelf-stable product that you can easily store and transport around. This is perfect for busy mothers who have to leave their children at the childcare centre during the day or at a guardian’s house while she’s busy. 

Freeze drying is done through the process of sublimation. This removes moisture from the milk while maintaining its chemical structure and nutritional content. The process involves freezing the substance, then placing it in a vacuum chamber where the frozen water is vaporised, leaving behind a dry and stable product that we know as freeze-dried breast milk

Let us break the process down further for you.

  1. Freezing the Breast Milk

After pre-treatment, the breast milk is frozen at a very low temperature (-50 to -60°C) to form ice crystals. The formation of ice crystals is a crucial step in the freeze-drying process as it helps remove the milk's water content to start forming it into the portable freeze-dried breast milk that we are looking for. 


  1. Vacuum 

After the milk is frozen, the chamber is subjected to a vacuum, removing any air or other gases trapped in the chamber. This is an important step in the freeze-drying process because it helps to prevent oxidation or other chemical reactions that could damage the milk. The vacuum also helps to maintain low pressure in the chamber, which is necessary for the sublimation of the ice crystals.


  1. Primary Drying

The frozen breast milk is then transferred to a vacuum chamber, where the pressure is reduced, and the temperature is raised to a point where the ice crystals can sublimate. They are converted directly from a solid to a gas, bypassing the liquid phase. This process is known as primary drying and can take several hours.


  1. Secondary Drying

Once the primary drying is complete, the temperature in the chamber is raised further to remove any remaining water molecules through secondary drying. This step is essential to ensure the final product is completely dry and stable, with a long shelf life. 

Once that is done, you get to store and carry around your breast milk and have access to it whenever you need it! It is so convenient that you can even have a stash at your parents’ place to ensure that you never have to worry about having milk on hand. 

Is this better than other breast milk preservation methods?
With this being a big concern to busy mothers everywhere, it is no wonder that many innovative solutions have surfaced over the past few years. With several methods available on the market for preserving and storing breast milk, we can start to compare the advantages and disadvantages of each method. 

Let’s compare the freeze-drying method to other commonly used preservation methods.


  1. Refrigeration and Freezing

Refrigeration and freezing are the most commonly used methods for preserving breast milk because most of us have a fridge and a freezer at home ready to use. Refrigeration and freezing are the most commonly used methods for preserving breast milk because most of us have a fridge and a freezer at home ready to use. 

Refrigeration involves storing the milk in a refrigerator at temperatures between 0 to 4°C, while freezing involves storing the milk at a temperature of -18°C or lower. These methods are simple, cost-effective, and readily available. However, they have limitations in terms of shelf life and convenience. 

Refrigerated breast milk can be stored for up to four days, while frozen milk can be stored for up to six months. Both methods require adequate space in the refrigerator or freezer, and the milk must be used within a specific period. Also, thawed milk must be consumed within 24 hours, making it a less convenient option for mothers who want to stock up on breast milk. 

How would you bring a stash of these out with you at the shopping centre if you are going to be there for a couple of hours and need milk on hand? 

  1. Pasteurisation

Pasteurisation involves heating breast milk at a specific temperature for a set period to eliminate any harmful bacteria. This method is commonly used in hospitals and milk banks to ensure the safety of the milk. Pasteurisation can be done by either the high-temperature short time (HTST) or low-temperature long time (LTLT) method. The HTST method involves heating the milk to 72°C for 15 seconds, while the LTLT method involves heating the milk to 62.5°C for 30 minutes. 

While pasteurisation is an effective method of preserving breast milk, it has limitations in terms of nutritional content. The high temperature in the process can destroy some of the nutrients and enzymes found in breast milk, reducing its nutritional value. As mentioned earlier, this is the biggest concern for mothers -- to ensure that breastmilk maintains its nutritional benefits regardless of its form. 

On top of that, it is very difficult for most of us to be able to do the pasteurisation accurately and effectively. This is not a convenient method for a typical mother out there. 

  1. Freeze-Drying

Freeze-drying breast milk is a relatively new technique that removes moisture from the milk while maintaining its chemical structure and nutritional content -- best of both worlds!  

The process involves freezing the milk, placing it in a vacuum chamber, and then removing the frozen water by sublimation. The resulting dried milk is lightweight, stable, and all you have to do is to add warm water to it anytime to get breast milk as good as ever. 

In fact, freeze-drying breast milk not only maintains the nutritional content of the milk, but has a longer shelf life compared to refrigeration and freezing methods. The dried milk is easy to store, transport, and reconstitute, making it a convenient option for mothers who want to ensure their babies can access breast milk at all times. 

But, how long does freeze-dried breast milk last?
Compared to the 6-month storage period of breast milk stored in the freezer at home, freeze-dried breast milk can last for up to 3 years if stored properly. This is possible because the freeze-drying process removes the water content from the milk, making it easy to store for longer periods without moisture present.  

The resulting powder can be stored easily in an airtight container in a cool, dry place, away from direct sunlight, and at room temperature. You can just take it out with you and add warm water to reconstitute it anywhere when you need it. 

It's important to note that once the freeze-dried breast milk is reconstituted with water, it should be consumed within 24 hours, just like fresh or refrigerated breast milk.

Is this method of storing and preserving breast milk safe for babies?

Yes, freeze-dried breast milk is safe for babies as long as it is prepared, stored, and handled properly. The freeze-drying process is designed to preserve the nutritional content and chemical structure of breast milk while removing water, making it lightweight and easy to store.  

Freeze-dried breast milk retains many of the important nutrients, enzymes, and antibodies that make it beneficial for babies. Research has shown that it can be an effective alternative to fresh or refrigerated breast milk. However, it's important to follow proper storage and handling procedures to ensure that freeze-dried breast milk remains safe for consumption by your baby.

How to store my breast milk?
After reconstituting your freeze-dried breast milk with water, it is important to consume it within 24 hours. 

To store your breast milk or your reconstituted freeze-dried breast milk, you can use sterile containers such as glass or BPA-free plastic containers or special breast milk storage bags designed for this purpose. But of course, for freeze-dried breast milk, you can always carry around a bottle of warm water together with the powder and reconstitute it anytime you need to instead of doing it in advance and storing it in the fridge after. 


Looking at the different methods to preserve and store breast milk, it is no wonder why freeze-dried breast milk is one of the more popular ways to go. 

The thoughtful process that goes into ensuring that your breast milk maintains its nutritional value, while making it so that busy mothers can always have some handy whenever and wherever, makes this method a popular choice. 


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