I dissolved the crude harmala freebase in warm vinegar. As expected, some insoluble impurities appeared.

I've let the sludge settle:



Unfortunately, the sludge takes about 50% of the volume and is very hard to filter (even coarse filtering glass wool gets clogged up quickly).

I am thinking about how to possibly separate the solids.

One idea was to decant the supernatant liquid and pour in fresh water, then repeat the process few times to extract most of the soluble harmala acetates, leaving the sludge behind.

Another idea was to add diatomaceous earth as a filter aid and try to filter the sludge.

What do you think?

Filtering never worked for me in such cases.
Decanting is the way to go.
strange thing is that you have so much sludge in this step. What is your extraction method?

I extract 1 000 g of seeds at a time in a 15 L pot. I combine 4 boils (acidified with vinegar, each about 3-4 liters of water), then boil the combined liquid down to about 4 L, filter with cotton, basify with sodium hydroxide, wash the free base 3 times (the supernatant liquid is only decanted). Then top up water to about 3 L and re-acidify with acetic acid.

Maybe there was some leftover base that could have done that.

I am able to filter the sludge with several filter changes, but its quite labor intensive process.

Maybe I could try filtering the initial aqueous extract with Celite to remove fine particles that could cause this kind of crumbling.

I have decanted the liquid and topped up with fresh warm water.

As you can see on the image, the solids look like a sponge. They are foamy and bulky and refuse to settle too much.

I perform harmala extraction and sometimes this appears, sometimes there are very little solids after re-acidification and are easy to filter. I am yet to find the factor causing this...

I am having a similar problem with the sludge. I used a video by gordotek, and after I acidified the fb alks, I added my salt solution to crystalize the harmalas. I have tried twice, and instead of turning to the needles, I’m getting that fluffy looking sludge. I was just gonna start a thread to ask this question but this thread seems relevant enough, but where am I going wrong turning this sludge to crystals? My sediment is much darker, more brownish than the pics by OP.

My last rue extraction with ungrounded seeds let me with sludge like you.
I just let few days filtering and it was nice. Not so much effort, just some time to filter.
To crystallize it, more washing step are needed.
Rue is very a long time extractions, i usually do it on 2 month from start to xtalz.

Time is an ally here

I have Redissolved and filtered about 5 or 6 times now. After filter, it dries into a clay like substance, almost like wet hash. Then I redissolve and add a salt solution that I thought was supposed to crystalize. But the precip is alway the sludge stuff. Never solid. Any insight?

What you're missing is HEAT. If your solution is not HOT (as in near boiling) when you're adding your salt for the manske it'll get all jelly crystal on you.

I had the exact same issue, and it was solved when I re-read the Tao of Rue extraction.


That's your issue-- you're too cool temp when you intro the salt.

I use a pint mason for 200g rue extraction manske stage.

after completely drying your alk "sludge" ahead of the manske, BOIL water in a kettle, put your "clay-like" alk ball/clumps in the pint jar, and pour just enough of that 200+ degree (F) water to cover it-- it will liquify. THEN add your splash of vinegar, a little more hot water (I get it to about the 200ml level here and stir well), THEN add your 30g powdered/pulverized rock salt to the jar (because my target volume is 300ish ml. stir as briskly as possible after dropping in the salt to aid in liquifaction-- I am usually re-heating the kettle here as I do this so my last 100ml pour is right at boiling-- which brings me to about 325ml total volume.

Stir until the salt is as dissolved as it can be (I always have a little sediment that won't dissolve but who cares it's coming out later anyway) then close the jar and leave it the heck alone to cool in stillness for a couple hours-- you'll get the crystal needles you're looking for exactly like in the Tao of Rue tek.

Hope this helps-- best of luck