The amount of botanical powder you use is up to you. 500-1000g is a good starting point. We use multiple kilos at a time.
Start by adding powder to ziplock bags and then add water. Zip the bags, kneading to mix. Add more water if necessary until all is uniform and the consistency of warm pancake syrup. Let it sit for 15 minutes, allowing the powder soak up the water and knead it again. Add more water if needed. Then take those bags and stash in your freezer overnight. The next morning, get them out and set them on the counter to thaw. In the evening you will knead them again and put them back in the freezer where they will stay until you are ready to move onto the next step.
When you are ready to do the rest, take the bags out of the freezer and tear them open and drop the frozen contents into a pot. Take 6% acetic acid (cleaning vinegar) and pour into the pot so it just covers the frozen botanical chunks. Cook on low for about 12 hours. You can either do this on the stove or put it into the oven at 200 degrees and let it go. (You don't want your temperature to exceed 200 as partial degradation of mitragynine can occur.) If cooking in the oven, be sure there are no meltable components like handles on your pot. When it is done, shut it off and let it cool overnight.
The next step is the most physically demanding, annoying, and messy. Use a metal colander lined with a flour sack towel (or something similar with a loose cotton weave) and a ladle to spoon out the mix and filter the solution from the solids. The plant matter isn’t good anymore, because the alkaloids have been separated into the surrounding liquid, but it could be used as compost possibly. Wrapping a fist-full mass of goop in the towel and twisting it will force the water out. You want the powder to be drier than wet sand before discarding it.
When the squeezing in finished, the solution now can be reduced down to syrup over low heat. A crock pot with a liner works well. Once it is syrupy, transfer to a silicone baking sheet for the final reduction and drying. You can do this in the oven as well. Be sure not to let it foam up from too much heat. Keep it in the oven with the light on.
Set aside the crock pot liner for now. As it dries (it can take weeks), take the crock pot liner and crinkle it around to pop loose the thin film of resin. Once you collect it, keep the liner handy for when you grind it all. You may have to break apart the resin as it dries.
Finally, after the product has dried and cured, you can grind the dry chunks into powder. And there you have it... black diamond extract.
