Saltpeter part 5

November 23, 2009 at 4:02 pm | Posted in saltpeter | 1 Comment

I almost decided to give up on the saltpeter. After all, my instructions said that after boiling the saltpetery liquid it should be put to settle and that “when it is very clear, an earthy thick sediment that is contained is removed, and it is put to boil again.” Yet, my salterpeter solution was not settling. At all. I left it for a few weeks, then checked it. Still black as ever. Then came Pennsic prep and the aftermath, and so on… it was now months later and the saltpeter was still a single black layer. There was no sediment. The word “clear” was not the adjective I would use to describe it. But then I decided that even if it wasn’t perfect, there certainly wasn’t any harm in continuing to try, right?

Therefore I got ready to boil my liquid a second time. Birringuiccio says that you should add rock alum. He also says that when the mixture begins to foam, you should add a strong lye, which will make the water “subside and become clear and beautiful and of a bluish color.”

Adding alum certainly got a stunning result. Every time I added some, the entire mixture would foam up in a pale tan foam. This was quite fun, and possibly the best part of making saltpeter so far. My lye, as previously documented here, was not the strongest solution. In any case, its addition did not suddenly make my murky brown liquid turn clear or bluish.

I boiled the liquid for several hours, until it had gone from about four inches of water to less than a half inch of liquid. At this point Birriguccio says to boil it until “the fine watery parts evaporate and the saltpetery parts become thick so that the water congeals when taken out”. I wasn’t entirely sure what he meant by congeals, but I chose to interpret it as crystalizing, like when you make sugar crystals. The condensed liquid looked about the right consistency for that, so I took it out and put it in a bucket “crossed inside with some sticks of wood for congealing on.”

Now I’m supposed to leave it for three or four days. If it is, indeed, like the sugar crystal candy I used to make when I was a kid, then I’d expect it to actually take significantly longer than that. The sugar crystal books would always say “a few days” and then take more than a week. So I’m not holding my breath. Wish me luck!