A cup of homemade yogurt made from whole cow’s milk contains roughly 8 to 9 grams of protein. That’s comparable to what you’d find in a store-bought plain yogurt, because the fermentation process doesn’t significantly change the protein content of the milk you start with. What does change the number is the type of milk you use, whether you strain the yogurt, and whether you add any protein boosters before fermentation.
Protein by Milk Type
The protein in your finished yogurt comes almost entirely from the milk itself. Starter cultures add a negligible amount. Since whole milk contains about 8 grams of protein per cup, your unstrained whole-milk yogurt will land right around that same 8 to 9 grams per cup.
Switching milk types shifts the number only slightly. Two percent milk yogurt falls in the same 8 to 9 gram range. Skim milk yogurt can edge a bit higher, closer to 9 to 10 grams per cup, because removing fat concentrates the other components, including protein. The differences between milk types are small enough that your choice of whole versus skim matters more for fat and calories than for protein.
How Straining Changes the Numbers
If you strain your homemade yogurt to make it thicker (Greek-style), you remove liquid whey and concentrate everything that stays behind, protein included. A typical batch loses about half its volume during straining, which roughly doubles the protein per cup in the finished product. That puts strained homemade Greek-style yogurt in the range of 15 to 20 grams of protein per cup, depending on how long you strain and how thick you let it get.
You do lose a small amount of protein in the whey itself, roughly 5 grams per liter of whey drained off. But because straining removes so much liquid, the net effect is still a significant protein boost in what remains. The longer you strain, the thicker and more protein-dense the yogurt becomes. Straining for 2 to 4 hours gives you a standard Greek consistency. Going overnight pushes it closer to a cream cheese texture with even more protein per spoonful.
Boosting Protein Before Fermentation
One of the simplest ways to increase protein in homemade yogurt is adding powdered milk to your liquid milk before heating and culturing. Two to four tablespoons of powdered milk stirred into one cup of regular milk adds 6 to 12 grams of protein. This also produces a thicker, creamier yogurt without any straining.
If you combine both techniques, adding powdered milk and then straining the finished yogurt, you can push a single cup well above 20 grams of protein. That puts your homemade yogurt on par with the highest-protein commercial Greek yogurts, often at a fraction of the cost. The powdered milk dissolves easily when you add it during the initial heating step, before the milk cools to culturing temperature.
Homemade vs. Store-Bought Protein
Plain store-bought yogurt and plain homemade yogurt made from the same type of milk will have nearly identical protein content. The difference shows up with commercial Greek yogurts, which are sometimes made using mechanical filtration or added protein concentrates that push their numbers to 15 to 20 grams per cup or higher. Some brands add milk protein isolates to reach those levels without as much straining.
With homemade yogurt, you control the protein content directly. Your baseline is whatever the milk provides, roughly 8 grams per cup for whole milk. From there, straining and powdered milk additions let you scale up predictably. A cup of homemade yogurt made with 3 tablespoons of added milk powder and strained for a few hours can easily reach 20 or more grams of protein, rivaling any commercial option without added thickeners or stabilizers.
Non-Dairy Homemade Yogurt
If you’re making yogurt from plant-based milk, protein varies widely. Soy milk is the closest to cow’s milk, typically providing 6 to 8 grams of protein per cup, so soy yogurt holds up reasonably well. Almond milk yogurt drops to around 1 to 2 grams per cup. Oat milk and coconut milk yogurts fall somewhere in between but generally stay under 4 grams. Fermentation doesn’t change these numbers meaningfully, so your starting milk choice determines the outcome. Straining plant-based yogurts can concentrate protein the same way it does with dairy, but you’re starting from a lower baseline, so the final numbers stay modest compared to cow’s milk versions.