Soap is made by mixing together lye, water, and fat, which causes a chemical reaction called saponification. It happens in nature when animal fats mix with wood ashes and rain water, but for more controlled results, use some store-bought lye crystals. For this recipe, gather exactly one pound of lard, 2.2 ounces of commercial lye, and 3.5 ounces of water. Soap making is part art form and part chemistry, but the chemistry part does require precise measuring. Use a sensitive scale to get the lye measurement correct, and use a liquid measuring cup for the water. Dissolve the lye in the water, outside if possible, or else in a well-ventilated space. Lye is a powerful caustic chemical, capable of delivering horrible chemical burns (remember the scene in Fight Club?). The lye and water mixture will become cloudy and make the container very hot to the touch. Make sure that everything you use in making lye soap is labeled, and never used for food purposes again.