What do you find is the best way of preparing your bark and syrian rue for extractions?

Is the ideal goal to reduce these substances to a fine powder?

Your help is much appreciated.

The idea behind powdering is to create the largest possible exposed surface of what you're powdering. By making the rootbark as fine as powder you create the maximum possible surface and therefore you'll get the largest amount of extract from it. I've never worked with Syrian Rue so I can't say anything about it, but as far as MHRB goes: Reducing it to fibers is good enough to get a high percentage yield.

If you want to reduce MHRB to powder, you'll have to buy a coffee grinder. A coffee mill(electric) or a blender will reduce most of it to fibers and a small quantity to powder. I personally use an electric coffee mill. I break my pieces of MHRB into small chips and do half a cup of them in the coffee mill and turn it on for 10 seconds. This will have reduced most of the chips to fibers. Every now and then you'll find a smaller particle in it. You can pick them out and blend em with the next batch or don't care about it. The amount of these larger chunks is quite small for me.

Listen to the sound your blender/coffee mill is making! If the blades are jammed by the chips or there is too much bark in the blender the engine will burn out. Make sure to let it cool down between runs.

i have found that the magic bullet works faster than a regular coffee grinder, and is also more durable.

once when I was staying on a beach in N. california I had to make my own mortar and pestle. I found this wonderful larger, rougher stone and another perfect palm-size stone with a sharp end and a blunt end. If I give myself over to the magical thinking that these magic plants seem to induce, these two stones seem to be auspicious indeed - especially in light of the subsequent experiences I had.

The whole place became infused with magic after that, actually...

i have tried using a M&P twice now, one made of smooth marble, the other a very rough (nooks and crannies) igneous rock of some sort.\
both times i pounded the bark, but it really had no effect aside from the audible percussion.
i found scissors and fingernails work better than mortar and pestle.
but that is just my experience...

With rocks isn't there a chance of contamination from mineral particles? Or whatever substance the rock is made up of? I know in this part of the UK most of the local mines extracted arsenic from rock!

I always use a coffee grinder, does the job almost instantly! Thing I don't like is the plume of dust that escapes if you don't leave it to settle long enough.. always imagine how many hits I lose lol

eh, yeah, maybe some mineral contaminants, I'm doing fine though!
I would have used one if I had had one and also a power outlet!

An it was just peganum harmala seed that I was grinding, my jurema was pre-powdered.

I tried using a mortar and pestle for the rue seeds and it was hopeless. It just flattened out the rubbery seeds with moisture soaking into the granite. No powder remained at all. When I added a small amount of water to wash the bowl I got a brown solution. I poured this muddy water onto a tray and let it evaporate. This left a mostly brown powder with a sticky yellow residue at the borders of the evaporated area.

I concluded a mortar and pestle was not the way to go for preparing syrian rue seeds, hence asking here before I wasted any more of my limited funding.

I will now investigate coffee grinders.

I asked in another thread if baking the syrian rue seeds at a low temperature might make them more brittle, and therefore easier to grind to a powder, but I think I asked in the wrong place as im new here.

So would baking the seeds in the oven help make them more brittle without damaging their contents? Perhaps this might work for the bark as well, as it too has a hard rubbery texture that doesnt lend itself to crushing to a powder, at least by hand?

i am not even going to pretend to know anything about rue (my oven-drying experience is restricted mostly to amanitas)
but lowest heat with the door slightly cracked is good for drying, and doesn't get hot enough to break down most chemicals, also you can use a fan to circulate air to keep the humidity and the heat low.

i don't know how the heat would affect the seeds, but my ass says "probably not" (its fun to talk out of there sometimes )

Thats my thinking too. If the rue seeds can sustain 100 degs in boiling water, then surely they can withstand 100 degs in hot air, is my reasoning. But this seemed so obvious I would have expected to see it mentioned in an extraction tek, which i have not, and therefore am here seeking clarification