Rendering is cooking a fatty meat or skin slowly until the fat liquefies and can be separated from the flesh, skin or cartilage. It can then it can be strained into a clean jar and kept on hand (in the refrigerator) for use in cooking. You can render the fat from bacon, pancetta, a real cured country ham such as prosciutto or Smithfield, or from a goose or duck to add marvelous flavor to a dish.
Cut the fat to be rendered into quarter-inch dice. In a heavy skillet, cook the fat covered over low heat stirring occasionally until the fat is liquid and the remaining flesh is crisp and brown. Strain into a clean dry jar and refrigerate when cool. You can use the crisp rendered bits in recipes or as a garnish. You can freeze them up to two months and reheat them in a covered skillet with a little water.
The yield of different fats varies greatly:
Bacon or Pancetta:
1 pound yields 1 cup (8 ounces) fat; 1 ounce yields 1 tablespoon fat.
Double Smoked Bacon : 1 pound yields 2⁄3 to 3⁄4cup fat; 1⁄4 pound yields about 3 tablespoons.