09/16/2026
Before a store within thirty miles of that house sold a can of lye, mountain women were making their own out of wood ashes, and they had a test for whether it was strong enough that works better than most people would believe. They floated an egg in it. 🥚
Here is how the system ran. All winter the hardwood ashes out of the fireplace and the cook stove went into a hopper out in the yard, a V shaped trough of split boards up on legs. Come soap making time you poured water in at the top, slow, and let it work down through the ashes for hours. What ran out at the bottom into the crock was dark amber and slick to the touch, and it was potassium hydroxide, real lye, leached straight out of the wood.
But lye has to be the right strength or the soap fails, and there was no way to measure it. So they used the egg. A fresh egg set into the lye water will sink if the solution is weak. If it is right, the egg floats with a circle of shell about the size of a small coin showing above the surface. Too strong and the egg rides up high like a cork, so you cut it with water and try again. Some women used a potato instead, and some used a chicken feather and watched to see whether the barbs dissolved.
That is a density test. It is exactly the principle behind a hydrometer, run with a hen egg by a woman who never saw a laboratory, and it is accurate enough to turn out good soap year after year from two things that cost nothing, ashes and the fat left from hog killing.
There is a habit of calling this sort of thing folk wisdom, as though it were luck that happened to work. It was not. It was a repeatable procedure with a quality control step built into it, worked out by people who could not afford a failed batch. 🧼 Your great grandmother was running chemistry. She just called it Tuesday.
