HEY! When brewing mimosa, I make sure it doesn't have any solid material in it before reducing. Then when I reduced it, when the water got really low, I noticed that some precipitate started forming. When it cooled, there was indeed a layer of tan precipitate that settles to the bottom. I wondered if that could possibly be dmt precipitating?

More likely microscopic (well, very small anyway) particulate from the mimosa. Powder that is small enough can get through filters. Salt wouldn't precipitate out of water (especially if it is acidic)... though perhaps if the concentrations were so high that the water couldn't hold any more, perhaps it is conceivable.

How low are you concentrating your brew?

I would guess that it is merely particulate matter. SWIM finds that sediment sludge at the bottoms of his jars as well.

I think the tan particles are, like Hyperspace Fool says, simply bits that are so fine they go through the filter. With my most recent boil of MHRB I have let them settle a few times during the process and just to make sure there wasn’t anything caught in it (the layer was quite thick at times) I have washed it with water, let it settle again and put the water back into the reduced brew.

The final boil and I have got everything down to ~450mL (from 400g bark and also some half-used bark from previous boils) and left it in a bottle to sit for a day and the sediment has changed colour dramatically, it is now a very dark colour. I will probably decant and wash with water again just to make sure not too much is caught in it as it is very concentrated now.

I think I may keep the last lot of very dark precipate separate from the decanted solution (I just washed it with vinegar water), base and extract that on its own to see if anything significant is lost when the solution is heavily reduced.

400 G in 450 ml! There is definitely a lot of actives in that sediment then. I typically make brews at a concentration of 6G/100 ml and notice a loss in potency if i discard the sediment that forms after its in the fridge for an extended time. This sediment forms even after multiple overnight decants and filterings. Keep that sludge! Curious, anyone know how much DMT acetate can be held in fridge temp water?

I have filtered warm Mimosa tea through a 0.2 u syringe filter after much previous filtration. The result was a beautiful reddish purple tea. I refrigerated it, and dark tan particles dropped out of this solution which surprised me. I would think that these were dissolved, and the temp drop caused them to come out of solution. Any chemists in the house here to weigh in on this???

I have settled on giving the sediment a wash with vinegar/water. A lot of colour coming out, first partial wash gives something very much closer to the average tan particles that fall out. Have another bit being washed in tandem too.