Solubility of harmala salts (made by adding fumaric/citric) will probably be even lower in acetone, so I dont think thats a good idea. Why dont you extract it using water/vinegar/sodium carb like the harmala extracton guide or same (but lye instead of sodium carb) as gibran's tek?

Someone here don´t remember who told me that people had not succeded in this with caapi leaf, probably to much other crap coming along from the leaves.

Honestly though i think i have had decent sucess with powderizing the leaf and doing several long soaks in acetone, using about 500ml total for about 50grams of leaf in 2-3soaks each for 2weeks.

the product is probably far from pure harmalas but works very well to make changa and the taste is although a bit chlorofully still acceptable, esp if i use mint leaf as my main ingridient.

Well you have to see what you find is a good way for yourself. I never extracted caapi leaves but I definitely would try it before wasting all that acetone (500ml for only 50g of leaves, thats a lot!), maybe the person did something wrong? Also maybe better get some rue/caapi vine instead for extracting harmalas in the meanwhile. Good luck

acetone is dirt cheap around here so i rather waste that than waste the leaves

Also i forgot to mention that heat my glass jar with the leaf and acetone in hot water bath, and from that i use it for about 1/10 of leaf material compared to how much leaf i used to make the xtract.

I don´t really like to use caapi leaf to infuse because of the taste, i usually use mint leaf.

try glacial acetic acid, the residue might be caused by the goo factor.i am not in my kitchen lab theese days but will be soon experimenting with harmala salts.

I tried to dissolve freebase harmala alkaloids from Syrian Rue and from Banisteriopsis Caapi in ethanol in order to make changa.
But both type of freebase harmala dissolve really bad in ethanol. There is still residue left in the bottom.

Did my extractions aren't perfect ?
Do I need to use heat for the dissolution ?

depends how you extracted your rue and how many purification steps u did, but there should be some impurities left at the bottom, just not much. i agree that harmala fb dissolves in ethanol slowly but it dissolves better than metanol and iso i think. definitely try a hot water bath while stirring to dissolve, it will help for sure.

I did a set of microscale isopropanolic recrystallization trials on some clean mixed harmala hydrochloride dihydrate [manske crystals].
In boiling 99% isopropanol I produced 16ml of a 0.8% solution and on cooling to -10°C I recovered 59% of the alkaloid as crystals. Given the large volume that would be needed, and the poorer crystal formation, I dont like 99% IPA.
In near-boiling 91% isopropanol I produced 12ml of a 2.9% solution and on cooling to -10°C I recovered 83% of the alkaloid as crystals.
The microscale work might have harmed recovery a little bit, particularly since I didnt have vacuum filtration. Larger batches should see a marginal to moderate improvement in yield. Another limiting factor is I dont know if some of the water of hydration may have been lost in the recrystallization. Isopropanol forms an azeotrope with water so boiling could have driven some water off, as 87.4% isopropanol boils lower than 99% IPA. Its also unknown how hard harm[al]ine tries to grab onto water as it crystallizes from organic solvents.
The commonly available 91% IPA seems a feasible solvent for recrystallization.

Procedure employed: