What Is Lye Soap?

Up until the 1850s, when the general store started stocking provisions, folks made most of their household supplies themselves, including lye soap. Three ingredients went into the making of lye soap: lard, lye, water and lots of hard work.

Lard was rendered and saved for soap-making from the annual hog kill that took place at the time of the first hard frost in autumn. Lye was made from the ashes left over from the wood stoves. (Most people kept a wooden bin with a side spigot just outside the house, into which they'd dump their ashes. When it came time to make lye soap, they poured water through the ashes and siphoned off the liquid lye.) The third ingredient of lye soap had to be supplied by a pair of hard working hands.

Lye is an extremely caustic agent, so the soap makers had to be careful to have just the right concentration. Too much lye would cause the soap to burn the skin, and too little would keep the soap from hardening. An old wives' tale held that lye was at the proper strength when depositing a floating egg into the mixture revealed only its tip.

To make lye soap, lard, water and lye are mixed together over an open fire in a big cast iron kettle, and stirred for hours with a long-handled paddle. It is said that when the paddle sticks straight up, the soap is ready. Lye soap is then poured into a large pan and allowed to dry and harden; a process that can take from two weeks to one month. After the lye soap hardens, it is cut into smaller bars for everyday use. People use lye soap to clean everything from their faces to their laundry. Today, many people still buy and use original lye soap.