Sunday, April 17, 2011

It's No Lye That Soap Is Made From Pot Ash

The word potassium came from the Dutch word "potash" literally referring to the substance left behind in the kettle or pot when wood ashes are leached with water and then left to evaporate--whence my title [insert snickering reference to the Dutch and their penchant for "pot"].

Scooping the ash out of the fireplace reminded me of how people used to make their own soap from lard. The first step in making soap is to have a good quantity of lye on hand. Lye is just concentrated potassium hydroxide, KOH, easily made from wood ash. recipe  Someone I knew back in Wisconsin used to make his own soap from used motor oil. The stuff worked quite well and really cut grease, but it smelled a bit like...used motor oil.

Potassium (but not sodium) is essential to plants and the growth of wild plants is often limited by their supply of K+.  This is also why fertilizer is classed according to its nitrogen-phosphorus-potassium (NPK) content. Plants don't have feelings and the proof is that they don't require the sodium crucial for propagating nerve impulses. I found a cool animation of how potassium and sodium are channeled and gated here. Back in my day we had no such animation tools and we had to imagine concepts like this. Here is a complete animated overview of how our brains communicate with our toes: link. Sodium and potassium are crucial for these processes.

In a way, this also describes how words become flesh.


  1. I disliked liked this post so much i took it apart and rewrote it. Still not happy. So it goes.

  2. I never knew that sodium was to blame for plants not having feelings. There are people who talk to their plants and rant at their trees, deriving solace from the process. They might disagree with you.

  3. I never knew that sodium was to blame for plants not having feelings.

    I thought everybody knew that! I attached a "hypothesis" tag just now out of abundance of caution.

    BTW, this post was worse than usual- I just found a egregious subject/verb mismatch in the last sentence. Please be so kind as to point these out in the future. :)

  4. Last weekend, our eldest reported back from a Scottish Festival in NC. Said he watched an open hearth cooking demo where corn bread was baked on wood ash over hot coals. According to the presenter, this method of cooking provided those who ate food cooked in ash with valuable minerals. After looking up "ash cakes", I read your post. Whatever other minerals are in wood ash, it sounds like Potassium heads up the list.

  5. @MamaM:

    This is also why wild fires are important for woods and grasslands. Trees and plants sequester the mineral which is scarce. Because potassium salts are so water soluble, they easily drain and wash away. After a fire, the potassium is released back into the soil for new plants to use.

    We have special receptors for sodium and potassium which came in handy when people moved away from the sea coasts and needed to find and recognize those minerals. Some animals apparently have highly specialized tastebuds for salts like calcium which we lack.

  6. Some animals apparently have highly specialized tastebuds for salts like calcium which we lack.

    e.g., large mammals and salt licks.

  7. I thought that you would take this thread in the direction of Potassium Nitrate (saltpetre), accused falsely of causing impotence in men and at the same time allowing gunpowder to go boom.

  8. Hey, thanks for the great idea LL! Mind if I steal it?

  9. Mind if I steal it?

    Can knowledge and ideas be sequestered?

    Whatever the answer, I appreciate their release in blog and comment.