A. Why only use 25ml of vinegar?
B. Will there be a problem, if more is used? Will adding more than 25ml of vinegar to the 300ml limonene pull out more impurities, than using just 25ml?

I'm practically completely ignorant to the science behind it, but that's why I am asking. Does this have something to do with pH? I understand that salting "2-3 times" or even more would be helpful in increasing yield. I don't understand why one should not use 50ml, or 75ml 2-3 times or more.

Thanks for the help, people, I would really like to know the science behind "why" one only uses 25ml of vinegar to 300ml limonene. Those numbers mean something, right?

As far as I know it is all about moles.
Each mole (number of atoms) has a different mass and you have to match up the moles for the required amount of vinegar.

Mescaline is 211.257 grams/mole
Vinegar (acetic acid) is 60.05 grams/mole

If you have 25ml of vinegar it is ~25g and at 5% it is 1.25g of acetic acid

1.25g of acetic acid = .0208 moles

.0208 moles of mescaline is 4.3975 g

Now the Sig Figs are off and this is all perfect-world scenarios but theoretically if mescaline is the only alkaloid that the vinegar salts then 25ml could salt out 4.3975g of mescaline. 50ml would be 8.795g and 75ml would be 13.193g and since 300ml of limonene likely can't even hold that much that is why.

Note: could be wrong, this is just grade 12 chem reasoning, it is hard to find the information on the net clearly you
Cheers

I've never done this extraction, but I wouldn't use exactly the amount of vinegar needed to react with the mescaline. Firstly, because in this case it's better to have excess of vinegar than lack of mescaline. Secondly, because acetic acid is a weak acid and mescaline is a weak base, which means that they don't fully dissociate in a solution and instead reach equilibrium of concentrations. If this doesn't make the other parts of the extraction difficult, I would add more vinegar than what's stoichiometrically sufficient.

SWIM mistakenly only used 15ml per pull on his last limo extraction, which yielded a very low amount (~200mg from 100g Torch).
He's using ~30-40ml this time and hopefully will get a more satisfactory result.

^He was talking about putting vinegar in d-limo, not cactus.

Anyway, I would stick to the ratio's, I'm not to savvy on the science but I most def. trust 69ron's math.

SWIM tried using more vinegar only to have to wait longer for the vinegar to evap. and getting poor results compared to less vinegar.

So the way i sees it is.....

Water takes a long time to evaporate, so because vinegar is mostly water, the more vinegar you use, the longer it takes said pull to evaporate. so the idea is to do a bunch of small acidic pulls with a minimal but adequate amount of an acidic water on each solvent pull, so when you combine your 2-3 or 4 vinegar pulls you have less end solution to evaporate....

SWIM has in the past used larger, unmeasured amounts of vinegar for the saltings (up to 100ml probably), and has only recently begun to use the proper amount of 25ml.

He has noticed an improvement in the yield and quality. Maybe a fluke, but it continues.