Why Freeze Milk?

A successful recipe depends on the quality of its ingredients. The fresher the ingredients, the better the final results. When it comes to cultured dairy, the quality of the milk is crucial to creating a successful end product.

Fresher milk will result in a better, more consistent cultured food. Dairy culturers often seek out locally produced milk, freezing it to keep it as fresh as possible. Others find freezing milk helpful since access to quality milk is limited by a short season. Although freezing milk is fine, it won’t keep forever, and freezing can change some of its properties. Those changes can affect a cultured dairy product.



Depending on the method of freezing milk, the fat or cream layer may separate from the milk. This separation is often more pronounced in cow milk, as goat and sheep milks are naturally homogenized. Separation can be caused by:

  • A natural separation in cow milk due to the time it takes the milk to freeze
  • A weakening of the membrane surrounding the fat globules, causing easier separation
  • A freezer with an automatic defrost cycle causing milk to thaw and freeze again
  • Thawing milk too rapidly or too slowly, especially cow milk.

Nutrient Loss

During freezing, as with other food preservation techniques, nutrients may be lost. Freezing food generally results in minimal loss, compared to other food preservation methods.

Off Flavors

  • Milk frozen in improperly sealed containers can come into contact with other flavors or odors in the freezer, resulting in an off flavor.
  • Any odors left in the vessel containing newly frozen milk will contribute negatively to flavor.
  • Exposure to air while transferring milk into different containers, or during the process of freezing, can cause off flavors.


Consider the following when using previously frozen milk:

  • Taste the thawed milk. If the off flavor is subtle it may go undetected in a strongly flavored ferment like milk kefir. Yogurt and cheese likely would carry the off flavor to the end product.
  • Use only fresh milk for cheesemaking. It tends to be a more finicky process than other cultured dairy products. Aged cheeses could be affected by fat separation. It may be difficult to produce curds or age/flavor properly with previously frozen milk.

What's Next?

Keep these considerations in mind when choosing milk for your next culturing project. Explore more advice for choosing milk below and let us help you get started making more cultured dairy products from scratch!