I know this thread is a few months old, however I was wondering about the benefits or disadvantages of decarboxylation of the bud before starting the process of freezing, mixing and extraction? In search of the perfect ethanol tincture.Ethyl acetate affects your central nervous system, respiratory system, eyes, and skin. It is a denaturant of ethanol used in industrial processes and I wouldn't even consider that option. Denaturants purposely make alcohol unsafe to consume. If you can't properly remove it to below 400 ppm you could hurt yourself. The food facilities using it have the proper equipment to remove all of it.
Isopropyl alcohol works well enough but pulls more waxes and pigments. It tends to leave a film on your crude extract and it is also not safe to consume its residue.
Ethanol is your safest bet. It is actually considered miscible in water, or basically very soluble. You can consume it safely at the residual level, and it doesn't target waxes and pigments as strongly as isopropyl alcohol.
I've spent the last 7 months heavily researching cryo-ethanol extraction for the hemp facility where I'm the production manager. I'll lay out a few pointers for you:
- Harvest, dry, and cure the buds just as you would if you were going to smoke them. Cool room, ~55% humidity, etc.
- Use the highest proof ethanol you can find, 190 is best.
- When you are ready to extract, pre-freeze your ethanol, buds, pyrex dishes, spatulas, etc. If it is part of the extraction process, it needs to be frozen. The colder you can do all of this then the less pigments and waxes you'll have reducing the final potency. You'll also retain more terpenes this way.
- Grind the frozen buds in a coffee grinder or nutribullet kind of blender. Do it just long enough to get them ground up, NOT powderized. More surface area = more efficient extraction. Do this as quickly as possible as the buds will pick up heat from being ground/chopped. Put them back in the freezer for a few hours.
- When doing the extraction have good ventilation. No open flames, sparks, etc. Have a fan blowing the air away from you. Do it outside if possible.
- Use about 3:1 ethanol:buds by volume. Any less ethanol and you might not extract all the oils, any more and you'll be wasting ethanol.
- Put the buds and alcohol in a container such as a half-gallon mason jar.
- Shake the hell out of it for about 5 minutes.
- Put it back in the freezer for about 10-15 minutes to soak.
- Pour this through your filter of choice, collecting it into some sort of pyrex dish (also pre-frozen).
- Evaporate the ethanol cold and slow so as not to lose those terpenes.
I know the extraction setup can vary wildly from what I've described. Feel free to give me more details on what your end product is going to be (edibles or smokeable oil) and I'll be glad to help more. If you're making edibles you'll need to heat/decarboxylate the oil before using it in food, if you're smoking it then your heat source will decarboxylate at the same time you're smoking it.