I followed the Lazyman's tek modified for 50 gram batches of Mimosa Hostilis Root Bark using bark obtained on ebay from user: xh_xavier

The ingredients used:
-500 ml of spring water
-50 grams of NaOH
-50 grams of MHRB
-unknown amount of naphtha per pull. 50 ml maybe? (non-heated)

Process:
-mixed H2O, NaOH, and MHRB together, let sit for 1-2 hours
-mixed in 1st pull of naphtha, let sit overnight or until minor emulsion settles
-pour off naphtha and evaporated under slight heat and gentle fanning
-repeat steps 2 and 3 one more time per 50 grams of MHRB

Yields:
1 - .70 grams = 1.40% yield
2 - .79 grams = 1.58% yield
3 - .92 grams = 1.84% yield

Average yield: approx 1.606%

Closing thoughts:
Logic demands an analysis of the wildly varying results. I should first note that extraction 2's yield was measured after a single recrystallization and foolish me, I forgot to weigh the initial yield. The reason for the recrystallization was an unfortunate contamination of the product with some basic MHRB goop, though, the yield does not seem to be affected near as much as I thought a recrystallization would. Using this info, one can conservatively assume that the initial product was around .85 - .90 g's
With the second extraction assumed to be .87 g's, the new average appears to still be around 1.66%. As for the dropped yield in extraction 1, I have no explanation. All 3 extractions were preformed identically and as this is my 4th or 5th time performing the 4-5 STB extractions required for 250 g's of MHRB, I would assume learning curve does not play a role in these results.

STB is a tricky monster. even with more than 10 under my belt I still get varied results.

why did you use spring water instead of tap water? Distilled water I would understand.

I live in a rural area so I have a well. When I say spring water, I'm implying that the water that I used was chlorine and fluoride free and straight from the ground.

DMTer- these are respectable results. Congratulations! Have you bioassayed any of them yet? If you're consistently getting ~1.6% then you must have found some rich bark. Around here, the average is more like 1.0% to 1.2%.

I agree with Stevowitz that STB yields seem to vary inexplicably, even within the same batch of bark. Perhaps it has to do with the base not fully penetrating the bark. A/Bs have been much more reliable, so they're now the route of choice for my friends. Either way, distilled H2O seems to increase yields slightly. Maybe try DH2O next time to see if you can get anything more out. I'd be interested to hear the results if you decide to give it a try.

Good work and thanks for posting your results!

-JM

I agree. At least in my experience.
A/Bs are a lot more work unfortunately as I have always gotten very nice results w/ A/Bs. White right off the bat and easy to do pulls on.
My STBs have given me a gamut of returns. From low yields to lots of yellow oils to normal yeilds of yellow or even waxy spice and even some really great neon yellow crystally stuff that was amazing.
But I do seem to do a little better each time so it just takes some getting the hang of and some is the variability of the material extracted from.

It's not like extracting mesc which always seems to go exactly the same way w/ the same results each time. ( Good results thankfully )

But nice yields there, glad that you got some good bark from them.