A ceramic bowl of thick white yogurt on a wooden tray

Skyr, yogurt or quark: which has the most protein?

Updated on 11 min read14 sources

Skyr is an Icelandic dairy product: skim milk is fermented with lactic acid bacteria and then strained until a thick mass is left, with about 11 g of protein per 100 g. Technically it's a fresh cheese, even though it sits next to the yogurt in the shop. Of the three, quark (izvara on Bulgarian labels) has the most protein, 11 to 14 g per 100 g. Skyr comes close, and regular yogurt has about 3.2 g. Here you'll see how they're made, a table of the protein in dairy foods, what 10 g of protein costs in Bulgarian shops and three savory recipes.

In short

  • Skyr is fermented skim milk with the liquid strained off. Labels in Bulgaria most often say 11 g of protein per 100 g.
  • Protein per 100 g: yogurt 3.2 to 3.6 g, strained yogurt 3.5 to 7.9 g, quark 11 to 14 g, kashkaval (yellow cheese) 20 to 28 g.
  • Skyr and Bulgarian yogurt rely on the same two main bacteria. The difference comes from the straining and from the skim milk.
  • On October 22, 2026, at eBag, 10 g of protein cost 0,47 to 0,73 € from most plain skyrs, 0,63 to 0,72 € from yogurt and 0,31 € from the best-value quark.

What skyr is and how it's made

Skyr comes from Iceland. According to a 2011 report by the Icelandic food research institute Matís, a dairy product of the same name was known in all the Nordic countries, but the skill of making it seems to have survived only in Iceland.

The recipe is short. Danish researchers described it in the journal Foods in 2022 (Srimahaeak and colleagues):

  1. Skim milk. Skyr is made from it, so the label usually shows about 0.2 g of fat per 100 g.
  2. Fermentation. Bacteria turn some of the milk sugar into lactic acid, and the milk sets into a gel. Traditionally a little rennet goes in too, but today most modern dairies work with bacteria alone.
  3. Straining. The liquid is separated from the gel, at dairies with a centrifuge or by ultrafiltration, through fine membranes. The protein stays, the water drains away.

That's why skyr is so thick. According to the same authors, skyr has 10 to 15% protein, and it has the typical tangy taste of cultured dairy.

11 gof protein per 100 g is what most of the plain skyrs we checked on the Bulgarian market say on the labelLabels at eBag and Lidl, October 22, 2026

Skyr or yogurt: what's the difference?

Both start with milk and the same bacteria. Bulgarian yogurt is made from pasteurized milk and just two kinds of bacteria: Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The milk ferments at 42-45 °C for 2.5 to 4 hours (Petrova and colleagues, 2021). The same two kinds are also the main starter culture for skyr. The story of the Bulgarian bacterium is in our article on milk protein.

The difference comes after fermentation. Yogurt is eaten just as it is in the tub, with all its water. Strained yogurt is partly drained, at home through cheesecloth. Dairies strain it with a separator or by ultrafiltration, according to the Tetra Pak handbook. Skyr is made from skim milk and strained even further.

Yogurt Strained yogurt Skyr
Milk cow's, 2 or 3.6% fat yogurt with varying fat content skim
After fermentation nothing is strained off partly strained strained, the thickest
Protein per 100 g 3.2-3.6 g 3.5-7.9 g 8.4-12 g, most often 11 g
Fat per 100 g 2-3.6 g 2-12 g 0-3.5 g, most often 0.2 g

The protein and fat figures come from the product labels at eBag and Lidl, checked on October 22, 2026.

Per 100 g, yogurt has about a third of the protein. But we eat it by the tub and cook a whole cuisine with it: tarator (cold cucumber and yogurt soup), snezhanka (cucumber and strained yogurt salad), the topping on moussaka. One 400 g tub gives 12.8 g of protein, as much as 2 large eggs (12.6 g according to USDA). Skyr comes in handy when you want more protein in less food.

Myth

“Skyr is just regular yogurt with a new name.” Skyr is made from skim milk and strained hard. That's why it has about three times as much protein as regular yogurt.

How much protein is in skyr, quark, cottage cheese, white cheese and kashkaval

The second and third columns come from the labels of products we checked in Bulgarian shops on October 22, 2026. The last one is from the US database USDA FoodData Central, for the closest food, where there is one.

Food Protein per 100 g, labels Fat per 100 g, labels USDA, protein per 100 g
Skyr, plain 8.4-12 g, most often 11 g 0-3.5 g no data
Strained yogurt 3.5-7.9 g 2-12 g 9.0 g (Greek, whole milk)
Yogurt 2% 3.2 g 2 g no exact match
Yogurt 3.6% 3.2-3.6 g 3.25-3.6 g 3.47 g (whole milk)
Quark (izvara) 11.1-14.3 g (20 g in one product) 0.7-5 g no exact match
Cottage cheese 9.8-13 g 2-6 g 11.1 g (12.4 g at 1% fat)
White brined cheese, cow's milk 14.25-17 g 19-23 g 14.2 g (feta)
Kashkaval, cow's milk 20-28 g 25-28 g 25.6 g (provolone)

The rule is the same as with skyr: the less water, the more protein per 100 g. According to USDA data, whole-milk yogurt is 87.9% water, cottage cheese 79.8%, feta 55.2% and provolone 41%. That's why kashkaval tops the table.

Strained yogurt is where the labels differ the most: from 3.5 to 7.9 g. If you buy it for the protein, check the number on the back.

Cottage cheese and quark are both fresh cheeses. For cottage cheese, bacteria sour skim milk until it sets, then the curd is cut into small grains, drained, rinsed and mixed with a creamy dressing. Quark (tvorog), which in Bulgaria is also sold as izvara, is set by the bacteria's acid alone (Tetra Pak). So cottage cheese comes in moist grains, while quark is drier and crumbly.

Close-up of crumbly white quark
On Bulgarian labels, quark has 11.1 to 14.3 g of protein per 100 g. Photo: MEALUP

More foods, from eggs to beans, are in our article on how much protein is in food.

What 10 g of protein costs in skyr, yogurt and quark

Skyr looks expensive. A 400 g tub costs 2,19 € at eBag and at Lidl, while 400 g of yogurt costs under 1 €. But the tub of skyr has 44 g of protein, and the yogurt 12.8 g. So we compared the price of 10 g of protein.

How to work it out

Protein in the pack = grams × protein per 100 g ÷ 100. Price per 10 g of protein = price ÷ protein in the pack × 10. Example with skyr: 400 × 11 ÷ 100 = 44 g of protein. Then 2,19 € ÷ 44 × 10 = 0,50 €.

Product and pack size Price Protein in the pack Price per 10 g of protein
Bredas low-fat quark, 500 g 2,19 € 71.6 g 0,31 €
Exquisa skyr, plain, 400 g 2,19 € 44 g 0,50 €
Madzharov quark, 350 g 2,04 € 38.9 g 0,53 €
Vereya yogurt 2%, 400 g 0,81 € 12.8 g 0,63 €
Vereya kashkaval, cow's milk, 400 g 6,98 € 106 g 0,66 €
Olympus strained yogurt 2%, 1 kg 5,26 € 79 g 0,67 €
Vereya yogurt 3.6%, 400 g 0,89 € 12.8 g 0,70 €
Vereya white cheese, cow's milk, 400 g 4,85 € 60 g 0,81 €
Olympus cottage cheese 2%, 180 g 1,92 € 23.4 g 0,82 €

Prices are from eBag.bg, the regular price for one pack without promotions, checked on October 22, 2026. The protein is from the label of the same product, as published on eBag.

The surprise: the 400 g skyr at 2,19 € came out cheaper per gram of protein than yogurt, 0,50 € against 0,63 to 0,72 €. The best value was low-fat quark. Cottage cheese in small tubs and white cheese were the most expensive on the list.

Prices vary within every group. For the seven plain skyrs without an organic label that we checked, 10 g of protein cost 0,47 to 0,73 €, and for the two organic skyrs 0,81 and 1,02 €. For yogurt it was 0,63 to 0,72 €, for kashkaval 0,55 to 0,94 € and for white cheese 0,62 to 1,08 €.

On October 22, 2026, plain 400 g skyr at Lidl also cost 2,19 € with 11% protein, so again 0,50 € per 10 g. On promotion, the numbers drop further. At Kaufland, from October 19 to 25, 2026, Madzharov BDS kashkaval (made to the Bulgarian state standard), 380 g, was reduced from 7,15 to 5,45 €, which takes it from 0,94 to 0,72 € per 10 g of protein.

Important

Prices change every week and differ between shops and towns. We didn't include products sold by weight at the fresh counter, because their protein isn't published online. Do the math with the price and the label from your own shop.

Three savory recipes with skyr and quark

The protein is calculated from the numbers in the tables. We count only the dairy and the eggs.

Skyr snezhanka (4 servings)

  1. Cucumber. Grate 1 large cucumber, salt it and leave it for 10 minutes. Then squeeze it out with your hands.
  2. Mixing. Stir 400 g of plain skyr together with the cucumber, 2 crushed garlic cloves, a handful of chopped dill and 2 tbsp of olive oil.
  3. On top. Sprinkle with crushed walnuts and serve cold.

Protein: 400 g of skyr gives 44 g, so 11 g per serving, not counting the walnuts. Snezhanka is usually made with strained yogurt. With skyr, the straining has already been done for you.

A thick white dip with dill and olive oil in wide white bowls
A thick dip with dill and olive oil: that's what skyr snezhanka looks like too. Photo: Fer ID / Pexels

Savory quark and egg breakfast bowl (1 serving)

  1. The quark. Put 150 g of quark in a bowl and fluff it up with a fork, adding 1 tbsp of olive oil, a pinch of salt and some summer savory.
  2. The vegetables. Add a chopped tomato, a chopped cucumber and a few olives.
  3. The egg. Top with 1 hard-boiled egg, cut in half, and sprinkle with paprika.

Protein: 150 g of quark (11.1 g per 100 g) gives 16.7 g, and the large egg (50 g) another 6.3 g. About 23 g in total. With low-fat quark (14.3 g per 100 g), it comes to about 28 g.

Pasta with quark and spinach sauce (2 servings)

  1. The pasta. Cook 200 g of pasta. Before you drain it, save a cup of the cooking water.
  2. The spinach. In a pan, wilt 2 handfuls of spinach with 1 garlic clove and a little olive oil.
  3. The sauce. Mash 250 g of quark with 3-4 tbsp of the pasta water until creamy.
  4. To finish. Turn off the heat, add the pasta and the quark to the pan, stir, and season with salt and black pepper.

Protein: 250 g of quark gives 27.8 g, about 14 g per plate, not counting the pasta. If you want a Cheddar flavor, sprinkle each finished plate with 1 serving (30 g) of MEALUP Cheddar. That's another 20 g of protein per plate.

Rigatoni with spinach and dollops of fresh white cheese on top
Pasta with spinach and fresh cheese. A quark sauce makes a similar plate. Photo: Nadin Sh / Pexels

Frequently asked questions

Is skyr a yogurt or a cheese?

Technically it's a fresh cheese. It's made from skim milk with bacteria, traditionally with a little rennet too, and then the liquid is strained off (Srimahaeak and colleagues, 2022). In shops it's sold next to the yogurt, and you eat it with a spoon just like yogurt.

Which yogurt has the most protein?

Of the products on the shelf, skyr: most often 11 g per 100 g. Next comes strained yogurt, up to 7.9 g on the labels we checked. For regular yogurt, it depends on the milk: cow's milk yogurt has about 3.2% protein, buffalo milk yogurt 4.2% and sheep's milk yogurt 5.2% (Petrova and colleagues, 2021). Fat content barely changes the protein: at both 2 and 3.6% fat, most labels say 3.2 g.

How much protein is in a tub of skyr?

It depends on the tub. A 400 g tub of skyr with 11 g per 100 g gives 44 g of protein. A small 150 g tub with 9.3 g per 100 g gives about 14 g.

What's the difference between quark and cottage cheese?

Both are fresh cheeses set by the bacteria's acid. Cottage cheese comes in separate grains that are mixed with a creamy dressing after draining, so it's moister. Quark is drier and crumbly. They're close on protein: on Bulgarian labels, quark has 11.1 to 14.3 g and cottage cheese 9.8 to 13 g per 100 g.

Is there lactose in skyr?

Yes, a little. Plain skyr labels show about 4 g of sugars per 100 g, and they come from the milk, meaning they're lactose. There's lactose-free skyr on the shelf too. If you have a milk intolerance or allergy, ask your doctor. There's more in our article on milk protein.

Yogurt keeps its place in tarator and under the moussaka. Skyr and quark come in handy when you want more protein in one spoonful. And of all the foods in the table, kashkaval still has the most protein per 100 g.

Sources

  1. Srimahaeak T., Petersen M. A., Lillevang S. K., Jespersen L., Larsen N., “Spoilage Potential of Contaminating Yeast Species Kluyveromyces marxianus, Pichia kudriavzevii and Torulaspora delbrueckii during Cold Storage of Skyr”, Foods, 2022
  2. Valsdóttir Þ., Sveinsson Þ. E., “Uniqueness of traditional skyr” (Sérstaða hefðbundins skyrs), Matís, 2011
  3. Petrova P., Ivanov I., Tsigoriyna L. et al., “Traditional Bulgarian Dairy Products: Ethnic Foods with Health Benefits”, Microorganisms, 2021
  4. Tetra Pak, Dairy Processing Handbook, “Fermented milk products”
  5. Tetra Pak, Dairy Processing Handbook, “Cheese”
  6. USDA FoodData Central, SR Legacy, “Yogurt, plain, whole milk” (171284)
  7. USDA FoodData Central, SR Legacy, “Yogurt, Greek, plain, whole milk” (171304)
  8. USDA FoodData Central, SR Legacy, “Cheese, cottage, creamed, large or small curd” (172179) and “Cheese, cottage, lowfat, 1% milkfat” (173417)
  9. USDA FoodData Central, SR Legacy, “Cheese, feta” (173420)
  10. USDA FoodData Central, SR Legacy, “Cheese, provolone” (170850)
  11. USDA FoodData Central, SR Legacy, “Egg, whole, raw, fresh” (171287)
  12. eBag.bg, prices and label nutrition values for 43 dairy products (skyr, yogurt and strained yogurt, quark, cottage cheese, white cheese, kashkaval), checked on October 22, 2026
  13. Lidl Bulgaria, “Skyr”, 400 g, product page, checked on October 22, 2026
  14. Kaufland Bulgaria, “Current offers: Dairy products”, valid from October 19 to 25, 2026, checked on October 22, 2026
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The whole story of protein