Freeze drying milk is not a new concept. Powdered milk, also called milk powder, dried milk, or dry milk, is a manufactured dairy product made by evaporating milk to dryness which can then later be reconstituted to the liquid form by adding water later. The first modern attempts at drying milk started as early as 1802 with specific processes for drying milk being created by 1837. Powdered milk is frequently used in the manufacturing of infant formula, confectionery such as chocolate and caramel candy, and in recipes for baked goods where adding liquid milk would make the final product too thin. During the 1960s, commercial infant formulas became popular, and by the mid-1970s they had all but replaced evaporated milk formulas as the "standard" for infant nutrition.

Typically when we think of breast milk storage, freezing in either a standard freezer or a deeper freezer have been the go-to for years. Milk that has been frozen correctly and stored in a deep freezer is optimal for about 6-9 months before the flavor begins to change. Newer guidelines are saying that frozen milk may still be good about a year in the freezer. But freeze-dried milk which can last from 3 to 20 years on the shelf! So the while the idea and concept of freeze dried breast milk isn’t new, it’s taking the market by storm with many new companies popping up in recent months. So let’s do a deep dive into the world of freeze dried breast milk, the pros and cons, and the expense. 

HOW IT WORKS

Sublimation is the fancy term for the freeze-drying process which basically means all the water has been removed from the breast milk and turns it into powder. Low temperatures are used for a long time in the drying process to ensure the nutrients in the milk are protected. Freeze drying is different than dehydrating, which uses very high heat and is relatively faster. With freeze drying, 'low and slow' is the name of the game to protect precious nutrients.

Here is the basics of a freeze-drying process:

• Deep freezing: Milk is deep frozen in a chamber at temps below -40 degrees Fahrenheit.
• Pressure dropping: Air inside the chamber is removed via a pump, which drops the pressure to create a vacuum. The low pressure turns the solid to gas. The vacuum pumps out the water particles.
• Drying: Ice crystals inside the frozen breastmilk is vaporized by drying the milk with alternating warm and cold air (without thawing the breast milk) leaving behind a breastmilk powder
• Packaging: The powder is sealed in special airtight bags or packages that protect against air, light, oxygen, and moisture. 
• Since everyone’s breast milk is unique, the company will send you specific directions for reconstituting your milk for baby to drink. This is NOT like standard formula where 1 scoop gets 2oz of water. Each bag of powdered breast milk will need specific amounts of water unique to your milk. 
• You should expect that however much milk you send will equal however much you receive back. If you send in 200oz of your breast milk, your powdered milk will make 200oz of breast milk when you’re ready to use it. 

Breast milk powder should be stored and prepared properly in order to prevent contamination with Cronobacter and other bacteria that can cause serious illness if safe handling guidelines are not followed.

THE PROS TO TRY IT:

• To preserve milk for longer than it would last in the freezer, especially if it is going to expire soon
• For the convenience factor
  • It’s easy to travel with or to ship to someone else
• Can help with high lipase
  • While freeze-drying doesn’t reduce the amount of lipase in the milk, by removing the water it reduces the enzyme activity that breaks down breast milk which can make the taste and smell much milder. For some whose baby rejected pumped milk in bottles because of high lipase may have a higher chance of taking it freeze dried
• For those who are doing elimination diets, this may preserve the milk longer for when your baby outgrows the allergy or intolerance so you can offer your milk later in your feeding journey
• In cases where breast cancer has been identified and a mastectomy would be life saving, freeze drying milk can ensure future children conceived after mastectomy could still receive mother’s own milk
• Can add some nutritional value to your older child’s meals by sprinkling it in purees or on solid foods, or even baking with it for the whole family
• Could be an option for surrogates or donor milk
• Saves space 

THE CONS AND THE COST

The big concern medical professionals have is that freeze-dried milk has not been widely studied. Yet. Most current health care providers will stick with AAP guidelines, CDC guidelines, FDA guidelines, and they have not released a formal statement on the safety and the efficacy of freeze-dried breast milk. But I would anticipate as it gains popularity and traction that eventually studies will be down on it. Without sufficient studies, it’s unclear if freeze-dried milk has the right protein, fat, carb ratio that infants need. We don’t know exactly how freeze-drying impacts the nutritional composition of breast milk. Some research suggests that breast milk's natural carbohydrate and protein content remains intact for up to six months after freeze-drying. But other studies report that freeze-drying may lower the amount of key antioxidants, like vitamin C, that are naturally present in breast milk. There really is a lack of evidence in terms of the nutritional safety of freeze-dried human milk at this current moment in time. Another concern is that freeze-dried milk does not undergo a pasteurization process which kills harmful bacteria. Pasteurization is avoided on purpose, in order to preserve the vital probiotics that are present in breast milk, and which would be destroyed with pasteurization. Just as bacteria can grow in freshly expressed milk if it is left at the right temperature for extended lengths of time, the same can happen with rehydrated breast milk powder. And there is room for error when making up bottles of freeze-dried milk. Each bag may require different amounts of water for rehydration, which means parents need to pay close attention to how they are preparing each bottle. Too much or too little water too often can lead to adverse effects in baby, like low sodium levels or not enough calories per feeding. 

Freeze drying breast milk is still a relatively new science when we are talking about using it for breast milk. Even though there are multiple new companies specializing in this, no matter what company you choose, it is going to be an investment. The cost to freeze dry your milk will vary based on the company you choose as well as the quantity of milk that you have.

Several companies will wait until they have your milk in hand before charging you. This way they know exactly how many ounces of milk there are! This is because we often aren’t accurate in our measurements of what we collect. The bag or the bottle lines can be inaccurate or we can tilt the bottle to see a different number than what’s actually there. Companies are very particular in measuring so that they can ensure proper ratios at the end too. They want to make sure they aren’t over or under charging you. Other companies may charge a flat rate or give you an estimate. Do your research but expect to pay several hundred dollars for your batch of milk!!

Freeze-drying human milk may still be an appealing option depending on your circumstances. If you are adamant about freeze-drying your milk, make sure to use a legitimate company with lots of reviews. And DON’T try it at home yourself as you're risking contamination.

References:

• Basics of Breastfeeding Support for the NICU or PICU Dyad. IABLE- Institute for the Advancement of Breastfeeding and Lactation Education
• Blackshaw, K., Wu, J., Valtchev, P., Lau, E., Banati, R. B., Dehghani, F., & Schindeler, A. (2021). The Effects of Thermal Pasteurisation, Freeze-Drying, and Gamma-Irradiation on the Antibacterial Properties of Donor Human Milk. Foods (Basel, Switzerland), 10(9), 2077. https://doi.org/10.3390/foods10092077
• de Halleux, V., Pieltain, C., Senterre, T., Studzinski, F., Kessen, C., Rigo, V., & Rigo, J. (2019). Growth Benefits of Own Mother’s Milk in Preterm Infants Fed Daily Individualized Fortified Human Milk. Nutrients, 11(4), 772. https://doi.org/10.3390/nu11040772
• Ginglen JG, Butki N. Necrotizing Enterocolitis. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513357/
• Jarzynka, S., Strom, K., Barbarska, O., Pawlikowska, E., Minkiewicz-Zochniak, A., Rosiak, E., Oledzka, G., & Wesolowska, A. (2021). Combination of High-Pressure Processing and Freeze-Drying as the Most Effective Techniques in Maintaining Biological Values and Microbiological Safety of Donor Milk. International journal of environmental research and public health, 18(4), 2147. https://doi.org/10.3390/ijerph18042147
• Lima, H. K., Wagner-Gillespie, M., Perrin, M. T., & Fogleman, A. D. (2017, August 2). Bacteria and bioactivity in holder pasteurized and shelf-stable human milk products. OUP Academic. https://academic.oup.com/cdn/article/1/8/e001438/4735239
• Meredith-Dennis, L., Xu, G., Goonatilleke, E., Lebrilla, C. B., Underwood, M. A., & Smilowitz, J. T. (2018). Composition and Variation of Macronutrients, Immune Proteins, and Human Milk Oligosaccharides in Human Milk From Nonprofit and Commercial Milk Banks. Journal of human lactation : official journal of International Lactation Consultant Association, 34(1), 120–129. https://doi.org/10.1177/0890334417710635
• Putting Evidence Into Practice: Freeze Dried Human Milk
• Salcedo, J., Gormaz, M., López-Mendoza, M. C., Nogarotto, E., & Silvestre, D. (2015). Human milk bactericidal properties: effect of lyophilization and relation to maternal factors and milk components. Journal of pediatric gastroenterology and nutrition, 60(4), 527–532. https://doi.org/10.1097/MPG.0000000000000641

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