To clear a cloudy liquid by removing the sediment. The most common method is to add egg whites and/or eggshells to a liquid (such as a stock) and simmer for 10 to 15 minutes. The egg whites attract any particles in the liquid like a magnet. After cooling for about an hour, the mixture is poured through a cloth-lined sieve to strain out all residue. Rendered fat can be clarified by adding hot water and boiling for about 15 minutes. The mixture is then strained through several layers of cheesecloth and chilled. The resulting top layer of fat should be almost entirely clear of residue.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.