Does Swiss Have Milk in It? The Definitive Answer

November 9, 2025 •

4 min read

Over 700 varieties of cheese are produced in Switzerland, and virtually all of them start with milk from cows that graze on mountain grasses. Therefore, the answer to the question "Does Swiss have milk in it?" is a definitive and resounding yes, as milk is its fundamental and primary ingredient.

Quick Summary

Swiss cheese is a dairy product made from cow's milk, which is transformed through a process involving bacterial cultures and rennet. The final product, especially after aging, contains very little lactose.

Key Points

Yes, it contains milk: The primary and foundational ingredient in Swiss cheese is cow's milk, like all natural cheese.
Low in Lactose: While made from milk, the cheesemaking process and aging consume most of the lactose, making it suitable for many with lactose intolerance.
Bacteria Create the Holes: The characteristic holes, or 'eyes,' are formed by carbon dioxide gas released by specific bacteria during the aging process.
Emmentaler vs. American Swiss: Authentic Swiss Emmentaler is typically made from raw milk and aged longer, resulting in a more complex flavor than its milder American counterpart.
Nutrient-Rich: Because it is made from milk, Swiss cheese is a good source of protein, calcium, and other essential nutrients.

The Simple Answer: Yes, Swiss Cheese is a Milk Product

Like all natural cheese, Swiss cheese begins with milk, most commonly from cows. The milk is delivered to a dairy, where it undergoes testing for quality and purity. Next, it is prepared for the coagulation process, which transforms it from a liquid into the solid curd that forms the basis of the cheese. Without milk, there could be no Swiss cheese, whether it's the domestic version found in supermarkets or the traditional Emmentaler variety from Switzerland itself.

The Milk Source for Authentic Swiss Cheese

Genuine Swiss cheeses, including the iconic Emmentaler AOP, are made from the highest quality raw cow's milk. The quality and character of this milk are influenced by the cows' diets, which consist primarily of alpine grasses and hay. This traditional approach to sourcing the milk is a key factor in developing the cheese's unique nutty and aromatic flavor profile. By contrast, the more mass-produced American version of Swiss cheese often uses pasteurized milk, which is heated to eliminate bacteria before the cheesemaking process begins.

The Cheesemaking Process: From Milk to Iconic Eyes

Once the fresh milk is collected, its transformation into Swiss cheese involves a careful, multi-stage process. Cheesemakers add lactic acid bacteria cultures and rennet, an enzyme that causes the milk to curdle into a gel-like solid. The resulting solid curds are then cut into smaller pieces and heated, which helps to separate the curds from the liquid whey.

The Role of Bacteria and Rennet

The famous holes, or "eyes," of Swiss cheese are not caused by mice, but by specific bacteria introduced during production. The bacteria, primarily Propionibacterium freudenreichii, consume the lactic acid in the cheese as it ages and produce carbon dioxide gas. As the cheese ripens in a warm cellar, the gas is trapped within the semi-solid matrix, forming the distinctive round openings. The size of the holes can vary depending on the aging time and conditions. Rennet, traditionally from calves but now often microbial for vegetarian options, is essential for thickening the milk and allowing the curd to form properly.

A Step-by-Step Cheesemaking Summary

Milk Collection and Testing: Fresh cow's milk arrives at the dairy and is tested for quality.
Curdling: Starter cultures and rennet are added, causing the milk to form a solid mass.
Curd Cutting: A cheese harp is used to cut the curd into fine grains to help expel whey.
Cooking and Pressing: The curds are gently heated and then pressed into molds to shape the cheese and drain more whey.
Brine Bath: The formed cheese is bathed in brine to add salt, develop a rind, and enhance flavor.
Aging and Eye Formation: The cheese is matured in a special cellar where bacteria produce gas bubbles, creating the eyes and deepening the flavor.

Is Swiss Cheese Safe for People with Lactose Intolerance?

While Swiss cheese is a dairy product made from milk, it is a great option for many people with lactose intolerance. During the cheesemaking process, the lactose (milk sugar) is consumed by the bacterial cultures and converted into lactic acid. As a hard, aged cheese, Swiss cheese contains significantly lower levels of lactose compared to milk or fresh cheeses. A single slice of Swiss cheese, for example, contains a minimal amount of lactose, making it easily digestible for most individuals who have trouble processing dairy.

American Swiss vs. Swiss Emmentaler: A Comparison

It is important to differentiate between the generic "Swiss cheese" found in many grocery stores and the authentic Emmentaler AOP from Switzerland. The two differ in origin, production, and flavor profile.


Feature	American Swiss Cheese	Swiss Emmentaler (AOP)
Origin	Created in the U.S. by Swiss immigrants.	Originated in the Emme Valley of Switzerland.
Milk Type	Often made with pasteurized cow's milk.	Traditionally made with unpasteurized cow's milk.
Aging Period	Typically aged for a shorter period, such as a month for Baby Swiss.	Aged for much longer, from 4 months to over a year, depending on the variety.
Flavor Profile	Milder, softer, and more buttery taste.	A more complex, nutty, and fruity flavor.
Holes ("Eyes")	Generally smaller and more consistent in size.	Can have irregular, walnut-sized holes.
Lactose Content	Low due to the cheesemaking and aging process.	Very low due to extensive aging and bacterial activity.

Conclusion

In short, Swiss cheese is unequivocally a dairy product made from milk. Its production relies on the curdling of cow's milk with cultures and rennet. The presence of the milk-based protein casein and its creation from a dairy source solidifies its classification as a dairy product. The key takeaway for many, however, is that while it starts with milk, the aging process results in a cheese with very little lactose. This makes it a delicious and versatile ingredient that can be enjoyed by many, including those with some degree of lactose intolerance. For a truly authentic experience, seeking out traditional Swiss Emmentaler cheese is a rewarding endeavor.

For more details on the production of authentic Swiss cheese, visit the official website of Cheeses from Switzerland.

Frequently Asked Questions

Yes, Swiss cheese is a dairy product. It is fundamentally made from cow's milk, which is curdled, processed, and aged to create the final product.

Many people with lactose intolerance can enjoy Swiss cheese. The cheesemaking and aging process naturally reduces the lactose content to very low levels, as bacteria consume the lactose.

Aside from milk, Swiss cheese is made with a starter culture of bacteria, rennet (an enzyme), and salt. The specific strains of bacteria contribute to its flavor and hole formation.

Not exactly. While American 'Swiss cheese' is inspired by Emmentaler, it is a milder, mass-produced version often made with pasteurized milk. Authentic Swiss Emmentaler is a PDO-protected cheese with a more robust flavor.

The holes, or 'eyes,' in Swiss cheese are created by carbon dioxide gas bubbles produced by bacteria during the aging process. The gas becomes trapped in the cheese and forms round openings.

No, vegans cannot eat Swiss cheese as it is made from cow's milk. Some vegetarian versions exist that use microbial rennet instead of animal-derived rennet, but they are still dairy products.

Swiss cheese is predominantly made from cow's milk. Traditional Emmentaler uses raw milk, while many American versions use pasteurized milk.