What Kind of Milk is in Skyr Yogurt and Its Nutritional Impact?

January 11, 2026 •

4 min read

Skyr, the Icelandic cultured dairy product often mistaken for yogurt, is traditionally made from skimmed cow's milk. This essential ingredient, combined with a meticulous straining process, is the secret behind its signature thick texture and incredibly high protein, low-fat nutritional profile.

Quick Summary

Traditional Icelandic skyr is made from strained skimmed cow's milk, which gives it a high protein, low-fat content. Modern commercial versions now also use whole milk or added cream for different textures and flavors.

Key Points

Skimmed Cow's Milk: Traditional Icelandic skyr is made from skimmed cow's milk, making it naturally fat-free.
High Protein: The straining process used to make skyr concentrates the milk proteins, resulting in a much higher protein content than regular yogurt.
Modern Variations: Contemporary commercial skyr is also available in low-fat and full-fat versions, using whole milk or added cream.
Requires More Milk: It takes about four cups of milk to produce one cup of skyr due to the extensive straining.
Probiotic-Rich: Regardless of the milk fat content, skyr is a fermented dairy product packed with beneficial probiotic cultures.
Digestion Friendly: The straining process removes most of the lactose, making skyr easier for some people with lactose intolerance to digest.

The Traditional Icelandic Method: Skim Milk

For over a thousand years, the base for authentic Icelandic skyr has been skimmed cow's milk. The fat is removed from the milk before it undergoes a specific fermentation and straining process. This decision to use skim milk, rather than whole milk, is fundamental to creating the unique characteristics of skyr. The removal of fat means that the final product is almost fat-free, making it a favorite among health-conscious consumers and athletes. However, this traditional method requires a significant volume of milk to produce a small amount of the final, thick product—up to four cups of milk for one cup of skyr.

The Fermentation and Straining Process

The creation of skyr is an ancient and precise process that concentrates the milk's nutrients. After being heated to pasteurize, the skim milk is cooled, and a special starter culture of bacteria is added. In some cases, rennet is also introduced, which technically classifies skyr as a soft, fresh cheese in Iceland, rather than a yogurt. The mixture is left to ferment before being cooled again and subjected to an extensive straining process. This step is what removes the watery whey, leaving behind a much denser, creamier, and more concentrated curd. The result is the lusciously thick, high-protein skyr we know today.

List of Steps for Making Traditional Skyr

Heating: Skim milk is heated to pasteurize it and destroy any unwanted bacteria.
Cooling: The milk is cooled to the optimal fermentation temperature.
Culturing: A starter culture of active bacteria, and sometimes rennet, is added to the milk to initiate fermentation.
Fermenting: The mixture is left to ferment, during which the bacteria convert lactose into lactic acid, causing the milk proteins to curdle.
Straining: The fermented curds are meticulously strained through a cloth to remove the whey, concentrating the proteins and creating the thick texture.
Finishing: The finished product is cooled and can be served plain or with toppings.

Modern Innovations: Full-Fat and Creamy Versions

While the traditional method relies on skim milk, modern commercial producers have introduced variations to cater to different tastes. You can now find low-fat, full-fat, and extra-creamy versions of skyr on store shelves. Some brands accomplish this by simply using whole milk, while others use skim milk and add cream back into the finished product for a richer flavor. These innovations mean consumers have more options, but it’s important to check the nutritional label if you are seeking the traditional low-fat benefits.

Skyr vs. Greek Yogurt: A Comparison of Milk and Nutrients

Skyr and Greek yogurt are often compared due to their thick consistency, but they differ significantly in their milk base, production, and nutritional profile. Below is a comparison highlighting their key differences.


Feature	Traditional Skyr	Greek Yogurt	Modern Skyr Variants
Milk Base	Skimmed cow's milk	Skimmed or whole cow's milk (often traditionally sheep's milk)	Skim, whole, or skim with added cream
Straining	Strained more extensively, resulting in a thicker product	Strained, but generally not as extensively as skyr	Varies by manufacturer, but typically involves more straining than standard yogurt
Fat Content	Traditionally fat-free	Varies widely, from non-fat to full-fat	Varies, with some versions containing 5% fat or more
Protein Content	Extremely high due to concentration, approx. 11g per 100g	High, but often slightly less than traditional skyr per serving	High, varies slightly with the milk fat content
Texture	Incredibly thick, smooth, and creamy	Thick, smooth, but typically not as dense as skyr	Varies from the traditional dense texture to extra-creamy options

Understanding the Nutritional Profile

Skyr's milk base is crucial to its nutritional profile. By using skim milk, traditional skyr becomes a high-protein, low-fat powerhouse. It is an excellent source of slow-release casein protein, which keeps you feeling full and provides sustained energy. It also contains billions of beneficial probiotics, which support gut health. While modern whole milk versions may have a richer flavor and higher fat content, they still retain a high protein count. For those with lactose intolerance, the straining process removes a significant portion of lactose, making it easier to digest for many individuals. You can learn more about skyr's health benefits from resources like Healthline's detailed article.

Conclusion: The Milk Behind the Icelandic Treat

In summary, the answer to "what kind of milk is in skyr yogurt?" is traditionally skimmed cow's milk. This traditional choice, combined with an intense straining method, is responsible for skyr’s characteristic thick texture and impressive low-fat, high-protein profile. While historical versions used sheep's milk, and modern markets offer convenient full-fat options, the foundation of this centuries-old Viking food remains the same. The type of milk used directly influences the final product's flavor, fat, and protein content, allowing consumers to choose a skyr that best suits their dietary needs and taste preferences.

Frequently Asked Questions

Traditional Icelandic skyr is made with skimmed cow's milk. However, modern commercial products are also available in whole milk, low-fat, and creamy varieties, so it's best to check the label.

Skyr achieves its thick consistency through a meticulous straining process. The fermented milk is strained extensively to remove the whey, which concentrates the remaining milk solids, primarily protein.

The milk used directly determines the fat content. Traditional skyr made from skim milk is fat-free, while versions made from whole milk or with added cream will have higher fat content, such as 5% or more.

Yes, skyr has a significantly higher protein content than most regular yogurts. The intense straining process removes more whey, concentrating the protein into a denser curd.

Many people with lactose intolerance can tolerate moderate amounts of skyr. The straining process removes a large percentage of lactose from the final product, but individuals should still test a small amount first.

While both are strained dairy products, skyr has traditionally been made from skimmed cow's milk, and its straining is more thorough. Greek yogurt can be made from skim or whole milk, and it is strained less than skyr.

Skyr was historically made from sheep's milk in Iceland but transitioned to cow's milk in the early 20th century, as dairy farming for cows became more economical. The traditional preparation has always emphasized a low-fat profile.