Quark is defined as "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."
To make it, pour 2 quarts of buttermilk into an oven-safe container with lid. Let sit in oven overnight (at least 8 hours), at 150 degrees. Line a colander with a clean cloth, pour quark into colander set inside a suitable sized bowl, let drain in fridge. If it drains too slowly, can fold cloth over the top, and set a sealed tupperware bowl filled with water on top. To use, can mix in a little milk until smooth. Goes well with a little honey and/or pureed fruit.