What Dairy Products Contain Whey?

November 11, 2025 •

4 min read

Milk is composed of two primary types of protein: casein and whey. Whey is the liquid portion that separates from the solid curds during the cheese-making process. A variety of dairy products naturally contain or are made using whey, providing an excellent source of this high-quality, easily digestible protein.

Quick Summary

This article explores the various dairy foods that naturally contain whey protein. Learn about milk, yogurt, and cheeses like ricotta and cottage cheese, all of which contain varying amounts of whey, and understand the difference between sweet and acid whey.

Key Points

All Milk Contains Whey: Milk naturally consists of about 20% whey protein and 80% casein protein.
Yogurt Has Whey (or its Byproduct): The liquid that separates on top of yogurt is whey. Straining yogurt, like Greek yogurt, removes much of the whey.
Ricotta is a Whey-Based Cheese: Traditional ricotta is made by reheating and coagulating the leftover whey from other cheese production, making it a high-whey product.
Cottage Cheese Includes Whey: This soft cheese contains both casein curds and some residual whey, which is the liquid often found in the container.
Processed Whey is Used Widely: The liquid byproduct of cheesemaking is processed into popular whey protein powders, concentrates, and isolates used in shakes and fortified foods.
Not all Cheese is High in Whey: Hard, aged cheeses primarily contain casein because most of the whey is drained during their production.
Whey Types Vary: Sweet whey comes from rennet-based cheesemaking, while acid whey is a byproduct of acidic dairy products like yogurt.

Milk: The Original Source of Whey

All cow's milk naturally contains both casein and whey proteins. Roughly 20% of the total protein in milk is whey, while the other 80% is casein. This means that consuming milk, in its liquid form, is the most fundamental way to ingest dairy-derived whey. The protein in milk is often referred to as a 'complete protein' because it contains both fast-digesting whey and slow-digesting casein, providing a sustained release of amino acids. This makes it a balanced and nutritious beverage.

Yogurt and its Byproduct, Yogurt Whey

Yogurt is another dairy product containing both casein and whey proteins. However, the ratio can vary significantly, especially in thicker varieties. Greek yogurt, for instance, is made by straining out much of the liquid whey to achieve its characteristic thick, creamy texture. The liquid that separates and pools at the top of a yogurt container is whey, and stirring it back in is a great way to add nutrients. The whey produced during yogurt making is often referred to as 'acid whey' due to the fermentation process. It is a valuable byproduct used in various applications, from baking to smoothies.

Cheeses with Significant Whey Content

While most aged cheeses are primarily made from casein curds, several fresh and soft cheeses are known for their high whey content.

Ricotta Cheese: The word 'ricotta' literally means 'recooked' in Italian, because it is traditionally made by reheating the whey left over from the production of other cheeses. This process coagulates the remaining whey proteins, resulting in a fresh cheese that is predominantly whey-based.
Cottage Cheese: This is a soft, fresh cheese made from the curds of milk, but it also retains a significant amount of whey protein. The watery liquid often found in cottage cheese containers is residual whey, and like with yogurt, it can be stirred back in.
Quark: A soft cheese similar to cottage cheese, quark is a creamy dairy product popular in Europe that contains both whey and casein proteins.
Whey Cheeses (Brunost, Mysost): Some traditional cheeses, particularly those from Norway like Brunost and Mysost, are made by boiling down whey to concentrate its lactose and other solids. These are sweeter and not primarily made of coagulated milk proteins like other cheeses.

Products Made with Processed Whey

Beyond naturally occurring forms, whey is a primary ingredient in many manufactured products. The liquid whey, once collected from cheese production, is processed into various forms, most commonly powdered.

Whey Protein Powder: This is the most concentrated form, available as concentrate, isolate, and hydrolysate. It's a popular supplement for athletes and those looking to increase their protein intake.
Protein Bars and Shakes: Many commercially produced protein bars and ready-to-drink shakes use whey protein powder as a key ingredient to boost their protein content.
Fortified Baked Goods and Cereals: Whey protein is increasingly added to foods like bread, muffins, and cereals to enhance their nutritional value.
Infant Formulas: Due to its nutritional value and ease of digestion, hydrolysed whey protein is a common component in hypoallergenic infant formulas.

Comparison: Casein vs. Whey-Rich Dairy

To better understand the protein content, here's a comparison of casein-dominant versus whey-rich dairy products.


Feature	Casein-Dominant Dairy (e.g., Cheddar)	Whey-Rich Dairy (e.g., Ricotta)
Protein Type	Primarily Casein	Primarily Whey
Digestion Speed	Slow-digesting, creating a feeling of fullness over a longer period.	Fast-digesting, providing a rapid supply of amino acids.
Production Process	Casein forms the solid curds, while most whey is drained away.	Made directly from leftover whey, capturing the whey proteins.
Common Examples	Hard cheeses like cheddar, mozzarella, and gouda.	Ricotta, whey protein powder, liquid whey from yogurt.
Best For	Sustained protein release, ideal for a snack or pre-bedtime.	Rapid post-workout recovery or when a quick protein source is needed.

The Journey of Whey: From Byproduct to Valued Ingredient

Historically, the liquid whey from cheesemaking was considered a waste product, sometimes discarded into rivers and streams. However, recognizing its nutritional value led to regulations and innovations that transformed whey into a highly sought-after ingredient. Initially, it was used as a cheap filler in products like ice cream, but modern processing techniques have allowed for the isolation and concentration of its high-quality proteins. The various forms of whey protein—concentrate, isolate, and hydrolysate—are now used in a wide range of food products, catering to athletes, health-conscious consumers, and those with specific dietary needs. The transformation of whey from a liability to a valuable resource is a prime example of sustainable food production innovation.

Conclusion: Whey's Widespread Presence

From the glass of milk you drink to the ricotta in your lasagna, whey protein is a fundamental part of many dairy products. Its presence varies depending on the processing, with some items like ricotta and whey powder being rich in it, while others like Greek yogurt have it partially removed. Understanding these differences can help you choose dairy products that best align with your nutritional needs and health goals.

Check out the U.S. Dairy website to learn more about dairy processing.

Frequently Asked Questions

Whey and casein are both milk proteins, but they differ in their digestion speed. Whey is a fast-digesting protein, while casein is a slow-digesting protein.

Most cheese is made from the solid casein curds, with the liquid whey being a byproduct. However, some cheeses like ricotta are made directly from the whey itself.

Greek yogurt has had much of the liquid whey strained out to make it thicker. The small amount of liquid that might pool on top is the residual whey.

Some forms of whey protein, particularly whey protein isolate, are processed to remove most of the lactose, making them tolerable for many with lactose intolerance. Those with a dairy allergy, however, should avoid it.

That liquid is whey. It contains protein and minerals, and stirring it back into the cheese can improve its texture and nutrient profile.

Whey is first separated from the curds during cheesemaking. The liquid whey is then filtered and dried, often using methods like spray drying, to create whey protein powder.

Whey protein powder (concentrate, isolate, or hydrolysate) is the most concentrated form of whey protein because it has been isolated and purified from the liquid whey.