Making Soap
Extract grease from animal fat by cutting the fat into small pieces and cooking them in a pot.
Add enough water to the pot to keep the fat from sticking as it cooks.
Cook the fat slowly, stirring frequently.
After the fat is rendered, pour the grease into a container to harden.
Place ashes in a container with a spout near the bottom.
Pour water over the ashes and collect the liquid that drips out of the spout in a separate container. This liquid is the potash or lye. Another way to get the lye is to pour the slurry (the mixture of ashes and water) through a straining cloth.
In a cooking pot, mix two parts grease to one part potash.
Place this mixture over a fire and boil it until it thickens.
After the mixture--the soap--cools, you can use it in the semiliquid state directly from the pot. You can also pour it into a pan, allow it to harden, and cut it into bars for later use.