Skyr
Food · Dairy · Food, Typed Supps
Skyr looks like yogurt but is actually a thick, strained cheese packed with protein and calcium.
Stage by stage
- Chewed & Swallowed (Mouth): Skyr's thick texture comes from straining out whey, which concentrates casein protein, calcium, and B vitamins into every spoonful.
- Curd Forms in Stomach (Stomach): Stomach acid causes the casein to clot into a soft curd that digests more slowly than whey-based dairy, releasing amino acids over a longer window.
- Absorbed in Intestine (Small Intestine): In the small intestine, digestive enzymes break the curd into amino acids and peptides absorbed into the bloodstream along with calcium.
- Fuels Muscle Repair (Skeletal Muscle): Amino acids, especially leucine, reach muscle tissue and support repair and growth, particularly when skyr is eaten around exercise.
Timing
Skyr doesn't need to be eaten with other food, but spacing protein-rich servings like this across the day (e.g., breakfast and post-workout) supports muscle protein synthesis better than getting all your daily protein in one meal.
Time to effect
- Hours to Weeks: Amino acids from skyr's protein begin appearing in blood within about 1-2 hours of eating and support muscle protein synthesis over the following hours, while measurable benefits for muscle mass, satiety, or bone density take weeks of consistent intake to show up.
Allergens
Contains: Milk. Derived from what this food is, not from a product label.
Eating patterns
Fits: Vegetarian, Pescatarian, Halal, Kosher, Keto, Gluten-free. Depends on the product: Low-FODMAP.
Satiety
240 on the satiety index, where white bread is 100 — very high. Modelled from the Holt et al. (1995) measurements.
Environmental footprint
3.2 kg CO2e and 628 litres of freshwater per kg, matched to "Milk" in Poore & Nemecek (2018), Science 360.
Cost band
Cheap — roughly £2.5 per kg, as a band midpoint rather than a price.
Key nutrients
Nutrition per 100g
- Calories: 53
- Protein: 11g
- Carbohydrate: 4g
- of which sugars: 2.9g
- Fat: 0g
- of which saturated: 0g
- Fibre: 1.2g
- Sodium: 38mg
Food vs. supplement
Skyr delivers slow-digesting casein protein alongside calcium, vitamin B12, and, in live-culture varieties, probiotic bacteria — a nutrient package a single protein-powder scoop doesn't replicate.
Kitchen tip
Look for "plain" skyr with a short ingredient list (milk, cultures, sometimes rennet) and add your own fruit, nuts, or honey — many flavored, fruit-on-the-bottom versions carry 15-20 g of added sugar per cup.
Common myth
"Skyr is just Icelandic Greek yogurt." In reality: Skyr is technically a fresh, rennet-set cheese, not a yogurt: it's made by straining skimmed milk with rennet added alongside the bacterial culture, which is why a typical 100 g serving of plain skyr contains around 11-12 g of protein and about 0.1-0.2 g of fat — notably higher protein and lower fat than most plain Greek yogurt at a similar calorie count. Note for the lactose-sensitive: straining reduces but does not eliminate lactose, and pasteurized (non-live-culture) skyr lacks the lactase-producing bacteria that help some people tolerate fermented dairy better than milk.
Recipes that use it
More in Dairy
In the glossary
Sources