Sour Cream Substitute For thick, creamy no-fat yogurt, line a strainer with a coffee filter and set it over a bowl. Add no-fat yogurt, cover with plastic wrap and refrigerate for at least an hour. The whey, or watery liquid, will drain out, leaving a thicker version. Now you have a sour-cream substitute. Substitute the drained yogurt in your favorite dip recipes or on a baked potato. Thanks to Sandy U. and St. Pete Times.