One of the oldest recipes to create lye is this one:
- Take well burnt ashes and put them in a barrel
- Fill the rest of the barrel with water
- Leave the suspension for a week or two
- You can now try the lye concentration with egg - if 2/3 remain above the water, the concentration is sufficient for domestic uses
- Separate the lye solution from ashes by carefully draining the water. You can also use filtration.
Now I know there are traces of various metals in us, as well in flowers and trees. But how can ashes accumulate such a big amount of sodium? And how is the sodium bound into it. How does it turn into hydroxide?