I've been playing around with the idea of casting aluminum With a smelter made our of old bricks and steel cans and making my own charcoal.
so far I've had some proof of concept success in making coffee grounds into charcoal burning scrap twigs from the yard and was going to try my first melt, but I decided that I needed to up my safety routines instead, as melting metal in a 100+ year old wood building that has been drying in the desert for its entire lifespan seemed a might iffy.
In moving the smelter I found I had a lot of very fine wood ash and decided that I would try to make "lyewater" like the stuff they made old school soap out of.
This is done by filtering water through the ash to extract potassium hydroxide. (note both potassium hydroxide and sodium hydroxide are known as "lye")
I poked a small hole in the bottom of a large plastic salsa jug, filled it with ash and put a jar under it and poured water into it. Got a jar filled with uh.... TEA! colored liquid.
So I have a jar of noxious liquid, no ph testing gear but I know that aluminum in a water-sodium hydroxide solution will produce hydrogen and aluminum oxide.
So I dropped a small piece of aluminum in the goo and got bubbles, I think I have hydrogen.