I'm extracting from acacia bark. I've had previous attempts which failed. I used Lex teks A/B method using 2kg of bark. I put my failure down to cutting corners in my extraction (not grinding bark enough) or more likely the bark being very low in alkaloids (only pulled 50mg out of 2kg).

I am reattempting a modified Lex method.
-Firstly I'm scaling down the operation to only 500g of acacia bark until I get efficient at the process (possibly maidenii, longifolia, obtusifolia or a hybrid collected form east Gippsland).
-Secondly I've performed an acid soak for a few days (2L of white vinegar and 2L of water) then 2 hour boil.
-Thirdly I want to perform a "STB" type extraction on the bark + vinegar solution.

My concern is how much lye I should use. I understand that the pH should be above 12, turning the solution a darker color the higher the pH is. I dont own a digital pH reader and can't find any litmus paper (anyone know were to get it in Aus?). Lexs tek says to use 100g for the 2kg of bark, should I use this same amount or considerably less because i have less bark/solution? Also, because I'm doing a "STB" with a acid soak, do i need to use more because of the bark material?

Any help is greatly appreciated. I hope it works this time! Will take pics if it works out.

Cheeser

Ive never done a tek like this but it would seem u should use less.. scaling it down seems logical. 2000/500= 4 4/100= 25 Ide use 25g lye

my suggestion find away of measuring the ph and you want exactly 12 ph not more becuase once you get to 13 you cant measure how basic it is