Individual stock recipes are given in each chapter where applicable. The trick of the trade for clarifying a stock that has become cloudy is to add ice to it. If the stock has become cloudy and gray, throwing ice into it can shock it to give up the blood and albumin still stuck in suspension in the stock. This is strictly an emergency procedure; clarifying can also be accomplished by letting the stock sit overnight, removing the solidified fat, leaving the residue at the bottom, and then bringing the stock to a simmer rapidly, skimming all the time. Do not let it boil.