Hello Michelle,

Here is a recipe and info I posted for a previous request for the same:

Here is a recipe for a substitute:

Homemade Sour Cream
From: Paula Peck's The Art of Fine Baking (1961)

2 cups of heavy cream
5 teaspoons of buttermilk

Combine cream and buttermilk in a screwtop jar. Shake the jar for a minute. Let stand at room temperature for 24 hours. If room is especially cool (on a cold winter day) let stand an extra 12 to 24 hours. Cream will thicken. Refrigerate at least 24 hours, preferably longer, before using.

NOTES: Homemade sour cream can be kept in the refrigerator a whole month, and it will get thicker and thicker and better and better. It can be whipped, if you make it with heavy cream, but be careful not to overwhip, as it will turn to butter in a flash.

Or, Quark may be an option for you - here is info from the Epicurious glossary:

Quark [qwark] - A soft, unripened cheese with the texture and flavor of sour cream, Quark comes in two versions - lowfat and nonfat. Though the calories are the same (35 per ounce), the texture of lowfat Quark is richer than that of lowfat sour cream. It has a milder flavor and richer texture than lowfat yogurt. Quark can be used as a sour cream substitute to top baked potatoes, and as an ingredient in a variety of dishes including cheesecakes, dips, salads and sauces.

Happy Cooking,

Betsy
recipelink.com