Swiss cheese is the most recognized eye-bearing cheese in the world. It belongs to the alpine cow's milk cheese family and owes its signature holes to a specific bacterial fermentation that no other widely sold cheese replicates at the same scale. The Emmental vs Gruyere comparison shows how two authentic Swiss AOP cheeses differ despite sharing the same alpine heritage.
In the United States, "Swiss cheese" refers to a domestically produced version inspired by Swiss Emmental. The two are related but not identical. True Emmentaler AOP from Switzerland uses raw milk, ages longer, and develops a more pronounced nutty flavor than American Swiss.
This profile covers both versions: what creates the eyes, how flavor changes with aging, and when to use each grade.
In This Article
What Swiss Cheese Is
Swiss cheese traces its origin to the Emme Valley (Emmental) in the canton of Bern, Switzerland. The original Emmentaler has been produced in this region since at least the 13th century, making it one of the oldest named cheeses in continuous production.
American Swiss cheese production began in the mid-1800s when Swiss immigrants brought cheesemaking techniques to Wisconsin and Ohio. The Green County region of Wisconsin and the Holmes County area of Ohio became the primary domestic production zones and remain significant producers today.
The critical difference between Swiss-made Emmentaler and American Swiss lies in the milk. Emmentaler AOP requires raw cow's milk from silage-free herds, which carries natural bacterial populations that influence the final flavor complexity. US Swiss cheese uses pasteurized milk with added cultures, producing a milder, more uniform product.
- Emmentaler AOP — raw milk, 4-14 months aging, nutty and complex, large wheels (80-100 kg)
- American Swiss — pasteurized milk, 2-6 months aging, mild and sweet, smaller blocks
- Finnish Swiss (Finlandia) — pasteurized milk, widely exported, medium flavor, smaller eyes
- French Emmental — pasteurized or raw milk, IGP protected, slightly different flavor from Swiss AOP
All versions share the same fundamental production method: a pressed-cooked curd process followed by a warm-room aging phase that triggers eye formation. The size of the eyes, depth of flavor, and texture vary by production origin and aging duration.
Eye Formation and the Science Behind the Holes
The holes in Swiss cheese are not random air pockets. They are carbon dioxide gas bubbles produced by Propionibacterium freydenreichii during a specific stage of aging called the warm-room phase.
After initial pressing and brining, Swiss cheese wheels move to a warm aging room held at 20-24 degrees C (68-75 degrees F) for 3-6 weeks. At this temperature, P. freydenreichii becomes active and metabolizes lactic acid in the paste, producing carbon dioxide and propionic acid as byproducts.
The carbon dioxide gas cannot escape through the dense, elastic paste of the cheese. Instead, it collects at weak points in the curd structure, forming the round cavities we call eyes. The propionic acid produced alongside the CO2 contributes the sweet, nutty flavor note that distinguishes Swiss from other alpine cheeses.
- P. freydenreichii activates at 20-24 degrees C during the warm-room aging phase
- Lactic acid is consumed by the bacteria, producing CO2 and propionic acid
- CO2 forms bubbles at weak points in the elastic curd structure
- Eyes grow larger with longer warm-room time and higher temperature
- Propionic acid creates the characteristic sweet, nutty flavor
Eye size depends on warm-room duration and temperature. Traditional Swiss Emmentaler develops eyes the size of walnuts or larger. American Swiss producers often use shorter warm-room periods, producing smaller, more uniform eyes that slice better for deli use.
A 2015 study by Agroscope (the Swiss federal agricultural research center) found that microscopic hay particles in the raw milk act as nucleation sites for eye formation. Filtered, pasteurized milk produces fewer and smaller eyes because those particles are removed. This explains why American Swiss cheese has consistently smaller holes than traditional Emmentaler.
Swiss Cheese Flavor and Texture
Young American Swiss (2-4 months) has a mild, sweet, slightly nutty flavor with almost no sharpness. It is the mildest of the alpine cheese family, less assertive than firm cooking cheese or Comte at equivalent ages. The authentic Swiss version, Emmentaler AOP, has deeper nutty flavor than any factory American Swiss.
Aged Swiss Emmentaler (8-14 months) develops a richer, more pronounced nuttiness with fruity undertones and a firmer bite. The flavor gap between young American Swiss and aged Emmentaler AOP is significant enough that they function as different cheeses in practice.
The radar above reflects standard American Swiss at 3-4 months. Aged Emmentaler AOP at 12+ months shows higher umami (55+), reduced sweetness (30), and increased salty (28) as moisture drops and flavor concentrates.
- Young American Swiss (2-4 months) — mild, sweet, clean finish, elastic texture, ideal for sandwiches
- Medium Swiss (4-6 months) — slightly nutty, firmer paste, better for melting applications
- Aged Emmentaler (8-14 months) — complex nutty and fruity notes, granular bite, board cheese
The texture of Swiss cheese is uniquely elastic among semi-hard cheeses. A thin slice of young Swiss cheese bends without breaking, making it one of the best cheeses for cold sandwich layering. This elasticity comes from the same protein structure that allows eye formation.
Swiss cheese has very low lactose content. The combination of bacterial fermentation during the warm-room phase and the aging process converts nearly all residual lactose. Most lactose-sensitive individuals tolerate Swiss cheese without difficulty.
Best Uses for Swiss Cheese
Swiss cheese melts cleanly at moderate temperatures, making it a reliable cooking cheese. The mild flavor blends into dishes without overpowering other ingredients, which is both its strength and its limitation.
For applications where you want melt without strong flavor dominance, Swiss is an excellent choice. For dishes where the cheese flavor needs to carry the dish (fondue, French onion soup), Gruyere or Comte perform better.
Swiss cheese is the default choice for sandwiches that require clean melt without strong cheese flavor. The sandwich cheese guide ranks Swiss alongside seven other options for cold and hot applications. The Reuben sandwich, patty melts, and Cuban sandwiches all rely on Swiss for this reason.
- Reuben — balances sour sauerkraut and salty corned beef with mild sweetness
- Patty melt — browns and bubbles under high heat without separating
- Quiche — melts into custard without dominating the filling flavors
- Gratin topping — forms a golden, cohesive crust at moderate temperatures
For cooking, always buy block Swiss and slice or grate it yourself. Pre-sliced deli Swiss has a starch coating on each slice that slows melting and can produce a grainy result in sauces and fondues.
The availability score of 95 reflects that Swiss cheese is one of the most widely stocked cheeses in US grocery stores. You can find it in virtually every supermarket deli counter and pre-packaged cheese section.
The flavor score of 42 positions Swiss at the mild end of the alpine family. This is not a flaw. Many recipes call for Swiss specifically because the cheese needs to melt and bind without asserting itself over other ingredients.
How to Store Swiss Cheese
Swiss cheese stores well because of its semi-hard texture and low moisture content. A properly wrapped wedge or block will hold for two to three weeks in the refrigerator without significant quality loss.
The main risk during storage is surface drying at the cut face. The cheese cutting guide shows how to minimize exposed surface area when portioning a large Swiss wheel or block. The eyes create additional exposed surface area inside the cheese, so Swiss dries faster than a solid-paste cheese like crumbly aged cheese when left unwrapped.
- Wax paper first — protects the cut face and slows moisture loss
- Loose plastic wrap second — prevents the cheese from drying without trapping excess moisture
- Cheese drawer at 35-40 F — consistent temperature prevents condensation and mold
- Replace wrapping every 3-4 days — fresh paper absorbs surface moisture and prevents sliminess
If white crystalline spots appear on aged Swiss cheese, those are calcium lactate or tyrosine crystals from aging. They are safe to eat and indicate proper maturation. If you see fuzzy mold on the surface, cut away at least one inch around the affected area. The remaining cheese is safe for a semi-hard variety like Swiss.
Our complete cheese storage guide covers wrapping methods and shelf life for every major cheese category, from soft bloomy-rind to hard aged blocks. The Swiss regional cheese guide also covers the Emme Valley AOP designation that American Swiss copies.
Buying Swiss Cheese
The Swiss cheese you find in a US grocery store is almost always domestically produced American Swiss, aged 2-4 months. For Emmentaler AOP from Switzerland, you need a specialty cheese shop or a well-stocked international section.
Baby Swiss is a distinct product, not just smaller Swiss. It uses a different culture ratio that produces smaller eyes and a creamier, slightly tangier flavor. It was developed in the 1960s in Ohio specifically for the American market.
Lacey Swiss (also called lace Swiss) has very large, irregular eyes and a thinner paste between them. It is a deli product designed for visual appeal and cold sandwiches. It melts poorly because there is not enough solid paste between the holes to form a cohesive layer.
Swiss Cheese Nutrition
Swiss cheese delivers strong protein and calcium per ounce with moderate fat and very low lactose. It is one of the more nutrient-efficient cheeses in the alpine family.
- Lower sodium — 54mg per ounce is among the lowest of any aged cheese
- Good calcium — 224mg per ounce delivers 17% of daily value
- Moderate calories — 106 per ounce, slightly below Gruyere and Cheddar
- Very low lactose — bacterial fermentation and aging convert nearly all lactose
The standout nutritional feature of Swiss cheese is its exceptionally low sodium. At 54mg per ounce, Swiss contains roughly one-quarter the sodium of Cheddar and one-third the sodium of Parmesan. For people monitoring sodium intake, Swiss is one of the best aged cheese options available.
These figures come from the USDA FoodData Central database for domestic Swiss cheese.
Swiss cheese's low sodium, strong calcium, and near-zero lactose make it a practical daily cheese for people managing blood pressure or lactose sensitivity.
Swiss Cheese FAQ
These are the questions we hear most about Swiss cheese, from eye formation to the difference between Swiss and Emmental.
The holes (called eyes) are formed by carbon dioxide gas produced by Propionibacterium freydenreichii bacteria during a warm-room aging phase at 20-24 degrees C. The CO2 cannot escape through the dense, elastic paste, so it collects at weak points in the curd structure and forms round cavities. The same bacteria produce propionic acid, which gives Swiss cheese its characteristic sweet, nutty flavor.
Not exactly. Emmentaler AOP is the original Swiss-made version using raw cow's milk, aged 4-14 months, in large 80-100 kg wheels. American Swiss cheese is inspired by Emmental but uses pasteurized milk, ages only 2-6 months, and has a milder flavor. Both share the same eye-forming bacteria and production method, but the raw milk and longer aging in Emmentaler AOP produce a more complex, nuttier cheese.
Yes, Swiss cheese melts smoothly at moderate temperatures and works well in sandwiches, quiche, and gratins. It is less flavorful when melted than Gruyere or Comte, so it is best used where you want melt without strong cheese flavor. Do not use Swiss as the sole cheese in fondue. It lacks the flavor depth. Combine it with Gruyere at a 1:3 ratio if needed.
Baby Swiss is a distinct American product developed in Ohio in the 1960s. It uses a modified culture ratio and shorter aging period to produce smaller eyes, creamier texture, and a slightly tangier flavor than standard Swiss. The name refers to the smaller eye size and shorter aging, not the wheel size. Baby Swiss is better for snacking and cheese boards than for cooking.
Yes. American Swiss cheese is made from pasteurized milk and is safe during pregnancy. Imported Emmentaler AOP uses raw milk but ages for a minimum of 4 months, well past the FDA 60-day safety threshold for raw-milk cheese. Both versions are considered safe by the FDA and most food safety authorities. Avoid any Swiss cheese that looks unusually moist or soft.