Butane extraction, sometimes referred to as butane hash oil extraction (BHO extraction), is a popular method of extracting the valuable compounds from the cannabis plant to essentially create a cannabis concentrate. The end result is known as butane hash oil (BHO), which is what is used to make up man other forms of consumable cannabis concentrates, like shatter, wax, honey oil, nug run, and so on.
Butane extraction is a form of hydrocarbon extraction, which is the process of using a hydrocarbon like butane or propane as the solvent to extract cannabis concentrates.
Among the many extraction methods processors are now using, BHO extraction remains popular because of its low-cost and effectiveness. It can be done at home without any fancy machinery.
To extract cannabis compounds from the plant, a solvent is typically used. In addition to butane extraction methods, other types of cannabis extraction include CO2 extraction, alcohol extraction, and dry sieving extraction. There is also what is known as the 'rosin' technique that is becoming popular.
For the butane extraction method, the user first tightly packs a glass cylinder with marijuana. At one end of the glass tube, a screen ensures plant material does not fall out. This screened end is held over another glass receptacle. Next, a butane torch is held or affixed to the opposite end of the glass tube, and butane is blown into the tube. The heated cannabis plant material will eventually release its oils and resins, which are collected in the additional container.
Before consumption, the oils and resins must be cleared (purged) of the butane solvent. To do so, the solution is simply heated in hot water (almost boiling). Butane bubbles form in the oil and eventually pop, releasing gas into the atmosphere. The final result is considered by many to be a clean, solvent-free product safe for consumption. However, some people will argue that any residual solvent left in the concentrate is unacceptable.
It is typically argued that BHO products are harsher on the lungs, even when a vaporizer is used.