Tinctures were the delivery method Western medicine used for marijuana for more than 90 years. Major U.S. pharmaceutical companies produced them from the midnineteenth century until cannabis was removed from the United States Pharmacopeia in 1942. The Marihuana Tax Act of 1937 made production of cannabis medicines prohibitively expensive, and there was a turn away from botanical medicines to synthesized and purified drugs than could be injected.
THC had not been discovered, and no one knew what was creating marijuana’s effects or how to standardize them. This created significant quality control issues. Our ability to test for the cannabinoids provides the opportunity to produce dose-controlled medicines. GW Pharmaceuticals in the U.K. has registered Sativex, a 50:50 THC:CBD extract, and Epidiolex, a high-CBD extract. Both drugs are alcohol-based marijuana tinctures that are sprayed under the tongue.
To strain the tincture, line a sieve or metal colander with cheesecloth and place it over a clean metal or glass bowl. Pick the type of cheesecloth based on how big the plant particles are that you want to catch. Cheesecloth comes in different grades, based on how tight the weave is, just as printing screens that can be used for sifting kief are graded based on how fine the mesh is.
Cheesecloth grades range from the very loosely woven #10 to the extra-fine #90. Unlike the symmetrical mesh of metal and plastic sifting screens, the number of threads per inch in cheesecloth varies horizontally and vertically, as seen below. Use a looser grade for straining freshly chopped plant material; it catches the plant material and does not clog.
Cheesecloth grade #60 to grade #90 is best for straining ground and powdered dried herb for tincture making to avoid sludge build-up. Using fine-grade cloth requires patience because it takes a long time for the extract to seep through.