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Swiss cheese is a firm cow’s milk cheese with round holes, called eyes, that form while it ages, and under FDA’s standard it must be at least 60 days old. In USDA SR Legacy data, an ounce of Swiss has about 111 calories, 7.6 grams of protein and 19% of the Daily Value for calcium, but only 2% DV for sodium, less than cheddar, Gouda or mozzarella in the same USDA data. This guide covers Swiss cheese nutrition, how the standard defines it, why does Swiss cheese have holes according to 2015 research, and what to know about lactose, allergy and pregnancy.
Peptide Labs does not sell Swiss cheese or cheese products. This article is general nutrition information, not medical advice.
Key Takeaways
- 21 CFR 133.195 defines Swiss cheese, also called emmentaler, with eyes throughout, at least 43% milkfat in the solids, at most 41% moisture and an age of at least 60 days.
- The holes come from carbon dioxide made by bacteria, which gathers at tiny particles in the cheese.
- Agroscope researchers reported in 2015 that hay particles from milk act as eye starting points.
- Per ounce, USDA lists 111 calories, 7.6 grams of protein, 19% DV calcium and 2% DV sodium.
- NIDDK names Swiss among hard cheeses that are lower in lactose than other milk products.
What is Swiss cheese?
In the US, Swiss cheese is a standardized food. FDA’s rule (21 CFR 133.195) says the name of the food is swiss cheese or, alternatively, emmentaler cheese, and that it “has holes or eyes developed throughout the cheese.” The minimum milkfat is 43% by weight of the solids and the maximum moisture is 41% by weight. Pasteurized dairy ingredients are allowed by the standard, and every Swiss cheese must be at least 60 days old.
The standard spells out the method. Milk is cultured with lactic acid-producing and propionic acid-producing bacteria and set with clotting enzymes. The curd is cut into pieces about the size of wheat kernels, stirred and heated to about 126 degrees F, then pressed into hoops. The wheels soak in a saturated salt solution for about 3 days, rest at about 50 to 60 degrees F for 5 to 10 days, and then move to a warm room of about 75 degrees F until they are about 30 days old, or until the eyes form. After that they are stored cooler for further aging.
One less familiar option in the standard: milk may be bleached with benzoyl peroxide. If it is, vitamin A has to be added back to the curd to make up for what bleaching destroys, and artificial coloring is not used. Other optional ingredients include calcium chloride and enzymes for flavor.
Why does Swiss cheese have holes?
The propionic acid bacteria named in the FDA standard produce carbon dioxide as the cheese sits in the warm room. For a long time, that gas was the whole explanation. Agroscope, the Swiss federal agricultural research center, notes that a 1917 survey article by William Clark already regarded bacterial gas as the leading idea and asked whether the holes formed at random.
In 2015, Agroscope and the Swiss materials research institute EMPA published a peer-reviewed study in the International Dairy Journal that filled in the missing step. Using X-ray computed tomography to watch cheeses over a 130-day ripening period, they found that the number of eyes could be controlled almost at will by the amount of hay particles added to the milk. Agroscope’s summary of the work:
- Microscopic plant particles, such as hay, contain tiny air bubbles that act as eye starting points.
- Carbon dioxide from propionic acid or lactic acid bacteria enlarges those bubbles into visible eyes.
- With hardly any particles, few holes form, because the gas largely escapes from the cheese.
- Hay particles decide where and how many holes form; they are not the only cause, since the bacteria still have to make the gas.
The finding also explained a puzzle cheesemakers had noticed. Agroscope reported that over the previous 10 to 15 years, Swiss Emmental had increasingly shown too few holes. Closed milking systems that replaced open pails lowered the risk of unwanted microbes in milk, and also reduced the hay dust that used to land in it, leaving fewer starting points for eyes.
Swiss nutrition per ounce (USDA)
These values come from USDA FoodData Central SR Legacy, per 1 ounce (28.35 grams), with % DV based on FDA reference amounts. SR Legacy has no separate entry for Emmentaler or for baby Swiss, so the plain Swiss entry is the reference here.
| Per 1 oz (USDA FDC ID) | Calories | Protein (% DV) | Saturated fat (% DV) | Sodium (% DV) | Calcium (% DV) |
|---|---|---|---|---|---|
| Swiss (FDC 171251) | 111 | 7.6 g (15%) | 5.2 g (26%) | 53 mg (2%) | 252 mg (19%) |
| Swiss, low sodium (FDC 168124) | 106 | 8.1 g (16%) | 5.0 g (25%) | 4 mg (0%) | 272 mg (21%) |
| Swiss, low fat (FDC 168141) | 51 | 8.1 g (16%) | 0.9 g (5%) | 56 mg (2%) | 272 mg (21%) |
| Process Swiss (FDC 170855) | 95 | 7.0 g (14%) | 4.5 g (23%) | 388 mg (17%) | 219 mg (17%) |
| Gouda (FDC 171241) | 101 | 7.1 g (14%) | 5.0 g (25%) | 232 mg (10%) | 198 mg (15%) |
| Cheddar (FDC 173414) | 114 | 6.5 g (13%) | 5.3 g (27%) | 185 mg (8%) | 201 mg (15%) |
USDA also lists an ounce of Swiss with 0.87 micrograms of vitamin B12 (36% DV), 8.5 micrograms of selenium (15% DV), 163 milligrams of phosphorus (13% DV), 82 micrograms of vitamin A (9% DV) and 26 milligrams of cholesterol (9% DV). For more sources, see our guides to B12 foods, selenium-rich foods and calcium-rich foods.
Is Swiss cheese healthy?
Like other firm cheeses, Swiss is concentrated: about 38 grams of water per 100 grams in USDA data. It brings protein, calcium and B12, along with saturated fat. Three points stand out.
Sodium
FDA describes 5% DV or less of sodium per serving as low and 20% DV or more as high. Natural Swiss, at 2% DV per ounce in USDA data, falls in the low range, while cheddar is at 8% DV and Gouda at 10% DV. Pasteurized process Swiss is a different product: USDA lists it at 17% DV per ounce. Our low-sodium foods guide explains how to compare labels.
Saturated fat
Swiss has 26% DV of saturated fat per ounce in USDA data, similar to other firm cheeses. The 2020-2025 and 2025-2030 Dietary Guidelines both say saturated fat should stay under 10% of daily calories, and the newer edition says that when people consume dairy they can include full-fat dairy with no added sugars. Low-fat Swiss is listed at 5% DV per ounce in USDA data.
Protein
At 7.6 grams per ounce in USDA data, Swiss has a little more protein than cheddar (6.5 grams) or Gouda (7.1 grams); aged parmesan has its own guide. Our high-protein foods list and cheese guide compare it with other choices.
Lactose, allergy and pregnancy
- Lactose: USDA lists 0 grams of lactose per 100 grams of Swiss, compared with 5.05 grams in whole milk. NIDDK suggests that people with lactose intolerance try “hard cheeses, like cheddar or Swiss, which are lower in lactose than other milk products.” Our lactase guide covers enzyme products.
- Milk allergy: milk is one of the nine major food allergens under US law. Low lactose does not make Swiss safe for anyone with a milk allergy.
- Pregnancy: CDC lists Swiss, Gruyere and Emmental made with pasteurized milk among safer hard cheese choices for people at higher risk of Listeria, and advises avoiding any cheese made with raw milk. The US standard allows Swiss made from unpasteurized milk, so check the label and ask your clinician.
Frequently Asked Questions
Why does Swiss cheese have holes?
Bacteria in the cheese make carbon dioxide, and the gas collects at tiny particles, such as hay particles from milk, which act as starting points. Agroscope research published in 2015 showed the particle amount controls the number of eyes.
Is Swiss cheese the same as emmentaler?
Under the US standard, yes: the food may be named swiss cheese or, alternatively, emmentaler cheese.
How many calories are in Swiss cheese?
USDA lists about 111 calories per ounce of Swiss, 106 for low-sodium Swiss and 51 for low-fat Swiss.
Is Swiss cheese low in sodium?
Natural Swiss has 2% DV sodium per ounce in USDA data, which is in the range FDA calls low. Process Swiss has much more, so compare labels.
Is Swiss cheese lactose free?
USDA lists 0 grams of lactose per 100 grams, and NIDDK names Swiss among hard cheeses lower in lactose. People vary, so start small.
Can you eat Swiss cheese while pregnant?
CDC lists Swiss made with pasteurized milk among safer choices for people at higher risk. Check the label and ask your clinician.
Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed October 2026.
Related guides: Gouda: Nutrition, Smoked Gouda and What the Label Means, Cheese: Nutrition, Types of Cheese and Is Cheese Healthy?, Parmesan: Nutrition, Lactose and Parmigiano Reggiano Rules, Gruyere: Nutrition, AOP Origins, US Labeling and Lactose.