|Table of Contents for Caveman Chemistry: 28 Projects, from the Creation of Fire to the Production of Plastics|
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You may be wondering where you can get a bit of ash. Anyplace, really, as long as it is fresh. Get it from a wood-stove, a fireplace, a campfire, even a barbecue grill. It is imperative, you understand, that it must never have been wet or your time will be wasted. Any container will do for leaching the soluble components. I would suggest that ubiquitous container, the twenty-first century equivalent of the gourd, the 2-liter soft-drink bottle. Fill it half-way with ash and add water up to the shoulder, as you did when making mead, and then put the top on the bottle. Shake your ash enthusiastically. It will probably look quite nasty.
Now, you will need a second container and it must be fireproof. You may use a Pyrex measuring cup, a beaker or an iron pot. If you are Athanor, you may even make your own pot. After your ashes have settled, the insoluble minerals will sink to the bottom and the charcoal will float to the top. The good stuff, remember, is in the water. We will use the insoluble ashes to filter the good stuff. Use a pin or a thumb tack to poke a little hole in the bottom of your bottle and place it into your pot. The smaller the hole, the better (but slower) the filtration will be. Remove the top from the bottle and the water will be filtered through the sediment as it leaks from the hole. The water collecting in the pot will appear quite clean and clear. You would think there is nothing in there, but you would be wrong.
Under no circumstances should you boil potash in an aluminum pot. Hot alkali reacts violently with aluminum. It will eat a hole in your pot and your ash will be all over the place.
All that remains is to remove the water from the pot. You may heat it on a stove or hot-plate or place it into a hot oven. Take care that the hot solution does not splatter or you will have an alkaline mess. When the water boils away, crystals of potash will remain. If you were a stickler for purity, you could dissolve your crude potash in water, boil the water away until a precipitate began to form, decant the remaining solution from this precipitate, allow the hot solution to cool and coagulate, and calcine the resulting solid to burn off any remaining charcoal, that is, you could do a second recrystallization. Of course, I am not such a stickler, so I am quite satisfied with my lovely, bitter, crude potash.
If you have followed my suggestions, your ash will be quite pale. It will be soluble in water, have the bitter taste of alkali and/or will turn pH test paper blue. You can tape the test paper into your notebook.