Double Cream

European recipes often call for double cream, or crème double. Double cream has an especially high butterfat content and is particularly useful as a sauce thickener because it requires less reduction. It is not marketed in the United States but can be prepared using homemade crème fraîche. To prepare double cream, line a large strainer with a wet napkin or a triple layer of cheesecloth, fill it with crème fraîche, tie it at the top, and suspend it overnight in the refrigerator over a bowl. The whey drains from the cream, leaving the remaining cream with a higher butterfat percentage. The approximate butterfat content of the finished cream can be calculated by measuring the amount of liquid (whey) that drained off the cream. For example, if 1 quart (1 liter) of cream released 2 cups (500 milliliters) of whey—that is, half its volume—then the butterfat content has been doubled to 70 percent, given that heavy cream is 35 percent butterfat.