BHO, or butane hash oil, is a potent concentrated form of cannabis. Butane hash oil uses, as implied in the name, butane as a solvent to strip essential oils, cannabinoids, and other compounds from the cannabis plant. This concentrate can then be processed into various consistencies such as shatter, wax, and budder. In 1977, Michael Stark wrote a book called Marijuana Chemistry​, which laid the foundation for the invention of BHO which wouldn’t really be heard of again until sometime in the late 90s.

During this time, cannabis was still heavily regulated in the United States. California legalized medicinal cannabis use in 1996 and allowed for patient co-ops to exist. Despite being legally available to patients, there still wasn’t a lot of research available on the efficacy and safe production of cannabis products or concentrates, as it was not federally recognized as a safe substance.

BHO was a very niche product in the early years. It was also very difficult to consume, as the only ways to really partake was either by soaking it into the flower bud itself or smoking it out of oil pipes in an unflattering fashion. Cannabis concentrates were also being propagandized as being as harmful as other heavy street drugs at the time, which meant that it was simply inaccessible and unattractive to most people.

It wasn’t until almost 2006 that BHO became a viable option for medical and recreational users. The underground glass pipe-making scene in California is infamous for its cultural significance and relationship with cannabis use in the US. Through their innovations a new method was invented in order to make smoking concentrates easier. The availability of these fashionable and practical smoking devices allowed for a more refined, sophisticated cannabis concentrate experience.

Another issue that producers faced in the early days was a lack of “high purity solvents.” The only type of refined butane that available to consumers was small canisters at head shops and corner stores traditionally used to fill lighters. This butane, however, was not purified, and contained mercaptans, an oily substance that can induce vomiting, headaches, and seizures. The BHO produced then was a very different product than what you can find in dispensaries today.

With its robust cannabis scene, California was primed for the evolution of concentrates but was reluctant to get behind butane. With a focus on healthy and sustainable products, BHO didn’t seem like the obvious choice for the industry compared to solventless extracts. It wasn’t until nearly 2010 when a California entrepreneur sought out true high purity butane directly from processing plants, free of mercaptans, that we began to see a shift. Once purified gas without impurities was introduced to the California market, the industry pivoted. Now, instead of a questionable concentrate that was more potent but made in relatively small amounts, BHO was produced more efficiently in a laboratory environment.

With the introduction of bulk quantity tanks, manufacturers began designing equipment to accommodate for the tanks. Instead of small cans and glass tubes, cannabis entrepreneurs are now able to utilize a fully closed loop system that can produce massive quantities of consistent, artisanal extracts that maintain the full spectrum benefits of the cannabis plant.

— By Maria Scothorn for Extraction Magazine