Can DCM be used to defat MHRB, or are DMT salts soluble in it as well?

don't use dcm to defat, acetate salts are known to be soluble in it
i wouldn't, no matter which acid you use

use xylene or naptha instead to defat.

and actually, the defatting step is more relevant to extracting with the phalaris grasses. it's often omitted when extracting with MHRB

SWIM uses DCM to defat chacruna all the time and gets fantastic yields of DMT. He uses citric acid as the acid.

DMT acetate is soluble in DCM though, so don't do it if you have DMT acetate. DMT citrate is totally insoluble in DCM. You could defat 10 times or more and not lose any DMT citrate to the DCM.

What about the DMT salt as it naturally occurs? One could defat with DCM in a soxhlet and THEN salt into acetate... just wondering since I may invest in a lab setup sometime in the future, and I'm trying to figure out a procedure that would entail minimal oversight and maximal yields.

I don't know.

The natural salt form of DMT is unknown. In mimosa it's likely to be DMT tannate because tannic acid is the dominant acid present. In chacruna or chaliponga, it's likely to be DMT citrate or something like that. It all depends on the plant.

The DMT in mimosa is the most difficult to extract.

Well there's an easy way to find out whether DMT-Tannate is soluble in DCM. Wash MHRB in DCM. Place DCM and distilled water together and add citric acid and mix. If the DMT-Tannate is soluble in DCM then there should be DMT-Citrate in the water.

You said "The DMT in mimosa is the most difficult to extract." could you please elaborate?

If you extract from whole Hawaiian chacruna at pH 4.0 with water and citric acid, defat with DCM, and then freebase at a pH of 8.5 (which is very low) and extract with DCM, you can still get a pretty decent DMT yield even with the low pH. If you do the same thing with powdered mimosa bark, because of the low pH used to freebase the DMT, you’ll get very crappy yields.

Many people find that with mimosa in order to get good yields you need a pH of 12 or higher. No one knows the exact reason for that, but it’s a matrix problem of some kind. Something present in the mimosa prevents the DMT from being easily freebased and extracted into the non-polar solvent at low pH values. It could be any number of compounds present in mimosa that are causing this problem.

Chacruna doesn’t have this serious matrix problem. SWIM normally extracts DMT from chacruna, and although pH 8.5 works to freebase the DMT, pH 9.5 is optimal with higher pH values having little to no benefit. But with mimosa, a pH value of 12 or higher is optimal according to many SWIMs, and even 9.5 gives poor results. It’s a common matrix problem and has nothing to do with DMT itself. To extract DMT without a serious matrix problem you only need pH 8.5, while pH 9.5 is nearly perfect. The pKa of DMT is very low: 8.6. That means at pH 9.6 90% is freebased and at pH 10.6 99% is. pH 9.5 is more than enough for an A/B extraction to be extremely efficient. You don’t actually need 99% because of the way A/B extractions work. I don’t want to get into the details of that but freebasing 90% works almost as well as 99% does. Either way you’ll get about 99% of the DMT into the non-polar solvent very easily.