Choose yogurt as a lower-fat alternative to traditional sour cream. Directly substitute whole milk yogurt or strained Greek yogurt at a one-to-one ratio for sour cream. If the sauce fails to thicken adequately, add a tablespoon of cornstarch mixed into a paste with water. If you want a richer result than you can get with yogurt alone, add 1 to 3 tablespoons of butter or margarine for every ¾ cup of yogurt. If you prefer a dairy-free option, choose soy yogurt.

Cottage cheese blended with an acid ingredient, such as lemon juice, yogurt or vinegar, provides a texture similar to that of sour cream. It also adds a tangy flavor. Combine one cup of cottage cheese with a tablespoon of lemon juice or vinegar to produce the equivalent of one cup of sour cream. Or combine equal parts cottage cheese and yogurt in a blender or food processor. Cottage cheese-based sour cream substitutes are lower in fat than the real thing, but may curdle if boiled or introduced to strong acids.

If you cannot tolerate milk, substitute tofu-based sour cream for the dairy variety. For every 8 ounces of silken tofu, add 3 tablespoons of lemon juice, 2 tablespoons of oil, 1½ tablespoons of sweetener and 1 tablespoon of soy milk. Puree the mixture in a blender or food processor until it is smooth and use cup-for-cup as a substitute for sour cream.

Crema is a Mexican variety of sour cream that is used to top many traditional dishes. It is sweeter and less tart than traditional sour cream, so you may need to add a little extra lemon juice or vinegar to the finished dish. Otherwise, it acts as a direct substitute for sour cream in chicken paprikash.

Similar to crema, creme fraiche is a form of slightly sour thickened cream. It resists curdling when heated, making it a good choice for chicken paprikash, but it lacks tartness. Use this slightly sweet product as a direct substitute for sour cream, but be aware that the final dish may require a little lemon juice or yogurt to replicate the flavor.