RSO is cannabis oil that has been extracted using ethanol and heated to remove the solvent, leaving behind a thick, tar-like oil that is very high in THC and other cannabinoids. RSO can be added directly to foods or taken under the tongue but is very concentrated so dosage should be carefully controlled.
RSO is often made from indica strains that are high in THC, though some sativa or hybrid versions also exist. The oil is usually quite dark and has an earthy, hash-like taste. Because it retains the plant's chlorophyll, RSO tends to be less refined than other cannabis oils like distillate.
RSO is a very versatile form of edible cannabis that can be added to many foods and drinks or taken on its own. It is often used by medical marijuana patients to treat a variety of symptoms and conditions. The effects of RSO tend to be full-body, long-lasting, and sedative. When used in cooking, RSO should be added at the end of the recipe to avoid heating it for too long, which can degrade some of the cannabinoids. Dosage for RSO typically starts around the size of a grain of rice.
Making RSO
To make RSO, high-quality cannabis material (such as buds and trim) is packed into a jar and covered with food-grade ethanol, like grain alcohol or isopropyl alcohol. The jar is left to sit in a cool, dark place for 4-6 weeks, shaking occasionally. This allows the alcohol to fully extract the cannabinoids and terpenes from the plant matter.
The material is then strained out using a mesh strainer or cheesecloth, and the remaining liquid is evaporated using a rice cooker, slow cooker, or double boiler on low heat until all the alcohol has evaporated and all that remains is a thick, tar-like oil. As the alcohol evaporates, the oil will become more and more viscous. It is done when almost all bubbles have stopped forming and the oil has a molasses-like consistency.
Allow the oil to cool, then use a spatula to scrape it from the pot and transfer it to an airtight container. Keep refrigerated for up to 6 months, or store in the freezer for longer term storage. When dosing RSO, start with a amount the size of half a grain of rice and increase slowly from there until you achieve your desired effects.