So I boiled down some Pedro juice to a tar using vinegar. I intend to further purify the tar using acetone. I was wondering if I could make a number of pulls with the acetone, then reduce the volume and precipitate the mescaline by titrating with HCl.

Would this work?

You would have to convert the mescaline to freebase first. Even then, I'm not sure that HCl would precipitate the mescaline from acetone. You'd probably be better off following a tek...

I thought mescaline acetate was soluble in acetone and the HCl was not.... Wouldn't a chemical precipitate out of a solution in which it is not soluble?

I'm no expert on mescaline extraction, or chemistry by a long shot, so take my words with a grain of salt.

I am not sure whether or not mescaline acetate is soluble in acetone, but as far as I know mescaline acetate + HCl = mescaline acetate in an acidic HCl solution. Whereas mescaline freebase + HCl = mescaline HCl. I could be wrong though, seeing as HCl is a much stronger acid than acetic.

I think you'd be better off converting to freebase, then titrating with HCl. But I really don't know enough to definitively say that your method will or will not work.

Sorry I can't be of more help!
Hopefully someone with more knowledge on the subject will chime in.