I am usually doing 200-250g MHRB extractions using A/B with salt. I am using filtered water (simply passed through a Brita filter).
This is what I do now:
- grind the shredded MHRB using electric coffee grinder
- weigh 200-250g MHRB in a tupperware box, cover with 600 ml water, mix well
- place in a hot bath (80 C) for a few hours
- freeze-thaw three times
- transfer soaked MHRB in a pot, add 600-800 ml water
- add some acid (glacial acetic, vinegar, ascorbic, citric, phosphoric - all these work fine) (this is optional, but maybe ascorbic acid or vit. C will prevent some oxidation; just keep pH around 4.0-4.5)
- heat up to 70 C while stirring (no need to cook!)
- cover with lid and let it sit for an hour or so
- strain to another (larger) pot through sieve (mine has approx 1-2 mm mesh) - the sieve should be fine enough to hold MHRB but large enough so the water is strained easily
- move MHRB from sieve back to pot, cover with 1 200 ml fresh water
- repeat twice (heat up, stir, infuse, strain)
- let the collected water extractions sit for 2 hours (so the sediment can settle)
- filter through wet cheese cloth folded twice (first decant the water, then add the sediment and help the water through with spoon, then add MHRB, close and squeeze the cheese cloth, discard MHRB which is now compact and dry)
- reduce the amount of water to 1 000 - 1 200 ml
- let the MRHB tea sit overnight (finer particles will settle)
- filter through loose cotton plug (vacuum filtration setup works best - avoid sintered funnel or paper filters as these will clog)
- heat the tea a bit, dissolve 80g salt in it
- add 50% sodium hydroxide solution by 5 ml steps with lots of mixing until pH reaches 12.5 (it usually takes 40-80 ml of the solution)
- transfer the basified tea to a container of choice (2L reagent bottle, 2L large Erlenmeyer flask, 2L separatory funnel)
- add 40-60 ml naphtha, gently tilt upside down and back for few minutes
- wait for emulsion to resolve, pipette/separate the naphtha layer
- put naphtha in a Pyrex dish
- evaporate 50-75% of the naphtha (until milky)
- heat up naphtha to dissolve micro-crystals
- leave the Pyrex dish at room temp. for 2 hours
- leave the dish in fridge for 4 hours
- leave the dish in freezer for 12 hours
Now I reuse the naphtha for next pull and heat up the tea to 40-45 degrees centigrade. I don't care about pulling plant oils as the extract usually goes to changa or get recrystallized in n-heptane to get crystals.
The filtering is not that necessary, it works fine even without any filtering and leaving all MHRB in the container. This obviously does not work for separatory funnel where you need filtered solution. Another advantage of filtering is having less trapped naphtha, less emulsion and one can magnetically stir the solution to resolve emulsion quicker.
Three or four pulls are usually enough to get almost all of the alkaloids out.