Giving up dairy doesn't mean you have to miss out on the tangy goodness that is sour cream. Traditionally made with cream that's been fermented with lactic acid bacteria, which thickens and sours the product, sour cream may be avoided by those with lactose intolerance, a milk allergy, vegans, followers of kosher dietary laws or those with dairy aversions. Plenty of non-dairy substitutes for sour cream are available; what you choose depends on your intended use of the "cream."
You don't have to miss out on the mellowing qualities and tang that a dollop of sour cream adds to soup, tacos, on top of nachos or as a side to potato pancakes. Purchased soy-based substitutes provide much the same texture and flavor as traditional sour cream. The ingredients in these typically include soybean and palm oil, tofu, carrageenan, locust bean gum, sugar and palm oil. Soy substitutes are all-purpose and can be used in baked goods and dips with minimal impact on the flavor and texture of the final product.
If you're also avoiding soy or prefer a more natural and less-chemically altered product, make a homemade cashew-based sour cream. Soak raw cashews in hot water for 30 minutes or longer; drain and blend them in a high-speed blender with a splash of cider vinegar, lemon juice, salt and enough water to create the consistency of sour cream. Use the cashew cream as a base for dips or alone on top of your next burrito. Avocados blended with lime juice, water and a bit of olive oil make a topping for Mexican-inspired dishes that mimics the smoothness and taste of sour cream.
Baking Without Sour Cream
Regular oil can replace sour cream measure for measure in a recipe for quick bread, muffins or cake. If you don't want to miss out on the light tang that sour cream adds to a baked good, try using 3/4 cup of canned coconut milk with a splash of vinegar for every 1 cup of sour cream. Soy yogurt also works measure for measure as a sour cream substitute in baked goods.
Avoiding the Fat
If you're still concerned about the fat content of substitutes such as oil, coconut milk and soy sour cream alternatives, use a fruit puree instead. Pumpkin puree and applesauce are two common options that you can substitute measure for measure for sour cream in baked goods. Applesauce offers the mildest flavor, but pumpkin complements carrot cake, spice cakes and gingerbread. Fruit puree provides moisture, but the absence of fat may result in a baked good that is slightly tougher and airier than one made with sour cream. As long as you don't mess with the other ingredients that provide fat -- such as oil, butter or whole eggs -- the texture change will be minimal.