Lye soap is made from wood ashes, water, and animal fat such as beef or pork fat. To make lye soap, the wood ashes are mixed with water to create lye, then combined with melted animal fat through either a cold or cooked process. Pioneers used lye soap for washing clothes by hand and bathing, as hygiene was difficult without running water and most families could only bathe once a week. Lye soap was also used to treat skin conditions and poison ivy.