Spoon yogurt into a colander lined with coffee filters or paper towels. Place colander over a bowl to drain; cover and chill 24 hours.
Discard the liquid whey, and knead salt into yogurt cheese, if desired. Wrap in plastic wrap, and store in refrigerator.
*Whole-fat yogurt makes a smooth, creamy cheese. Nonfat yogurt works equally well, although the texture is slightly grainy. Nonfat yogurt cheese was often used as a substitute for cream cheese before the advent of reduced-fat and fat-free cream cheese.