Put the yogurt in a strainer over a bowl. Or you can use a coffee filter, piece of muslin, or a paper towel and place it in a small sieve over a bowl. Cover and let it drain in the refrigerator for 12 hours or overnight. It becomes quite firm and the small lumps disappear, which makes it ideal for use in sauces. The liquid whey drains into the bowl, leaving you with thick, creamy yogurt cheese.