Butane Hash Oil (BHO)
A cannabis extract that uses butane as the primary solvent during the extraction process. Butane Hash Oil is most commonly referred by its initials BHO, and encompasses a myriad of textures and consistencies. Butane Hash Oil extraction can render Badder, Crumble, Sauce, and Shatter, depending on starting material, apparatus used, and techniques applied.
“I just cleaned my banger, break out the BHO!”
“That may look like rosin, but its Butane Hash Oil.”
“Can I twax this joint with some of your BHO?”
More about Butane Hash Oil
What is BHO?
Butane Hash Oil, or BHO, is an extract, which is a type of cannabis concentrate that’s produced using solvents. A label that reads “BHO” only tells part of a concentrate’s story. Consumers can’t judge a concentrate by appearance or aroma alone.
When it comes to any concentrate, remember that the starting material will dictate the quality of the finished product. Starting material refers to the cannabis used to create the concentrate. A combination of the flower used and purity of the final product is what separates high-quality concentrates from the product that users avoid.
BHO’s consistency is primarily dependent on the techniques applied during the extraction and the post-extraction purge stage, but there are some cannabis strains that tend to produce a particular texture. Though methods vary, the goal is largely the same: Deliver the desired characteristics of the cannabis plant sans the tar and ash-producing matter. This is accomplished through a steady series of separation and purification.
Butane is a highly flammable substance and hash oil production is extremely dangerous if done by inexperienced technicians with improper equipment and ill-equipped facilities.
What is Butane?
Butane is a simple hydrocarbon, part of a family of organic molecules including ethane, methane, and propane. Butane is pumped from natural gas wells and then purified and compressed into a liquid for storage and use. Butane is easy to capture and relatively affordable to produce. Extractors typically only use highly refined, lab-grade butane that is 99.5 percent to 99.9 percent pure. Butane canisters found in stores should never be used as they contain toxic mercaptan that is used to propel the solvent out of the bottle. Mercaptan is an additive to give a rancid odor to natural gas, which is naturally colorless and odorless and couldn’t otherwise be detected if it leaked.
Butane is used primarily for its efficiency and low boiling point. This allows extractors to remove the solvent from the extracts without altering any of the cannabinoids or terpenes that were removed from the plant material, and ensure that no residual butane is left in the finished product.
What is a Crude Extract?
Crude refers to unrefined cannabis extract, or the oil produced from the initial extraction, the first pass through. From there, the oil is either winterized for further refinement or decarboxylated and infused into products such as edibles, creams and tinctures.
The winterization, or “de-waxing,” process happens after the butane is purged from the oil, creating a purer concentrate. Technicians remove the undesirable waxes, fats, lipids, and chlorophyll in three main steps. First, the oil is mixed with ethanol and the mixture is frozen to allow the undesirable compounds to fall out of solution. The solution is then passed through a filter that retains the waste products. Finally, the wax-free oil is distilled to remove the ethanol.
The winterization process helps prolong the shelf life of Shatter by ensuring that it will not auto-budder. Auto-buddering is when the color and consistency of shatter starts to turn darker and take on a crumbly or waxy consistency.
The history of BHO
The ’70s usher in a new era of hash making
Butane Hash Oil is hardly the first concentrate. Civilizations throughout the globe have been separating the resinous trichomes from the cannabis plant for thousands of years. By 900 AD, hashish had spread throughout Arabia.
Introducing the cannabis to a solvent was an innovation documented in 1971 D. Gold’s “Cannabis Alchemy: The Art of Modern Hashmaking,” the first to outline the procedure for this type of extraction to the general public. Gold’s book supplied a how-to for homemade solvent-based extracts, as well as their mass production. Gold was inspired to write “Cannabis Alchemy” after an explosive lab accident left him severely burned and hospitalized for several weeks.
The text also unveils an untold history of extraction experiments through letters sent to the manufacturer of Gold’s extraction machine. From the earliest extraction origins, extractors were competitive about their hash making, regaling stories of their spoils from “Texas Super Hash” to experiments with psilocybin, or “magic mushrooms.” These concentrates are worlds apart from what we see today. In some letters, extractors describe substances that look like black tar — now known as crude extracts — or extracts purged by laying slabs in the sun on top of roofs. Appearance aside, the largest difference is that none of these extractors used butane as their extraction solvent, which started to take root in the early 1990’s.
Indra B. Gurung and the Vaults of Erowid
“The Vaults of Erowid”, or www.erowid.org, was the ultimate online gateway to psychedelic knowledge in the ‘90s. The website contains in-depth knowledge on drugs from LSD to cannabis. On May 1, 1999, Indra Gurung (real name: John Henry Davis) added instructions on how to “turn trash leaf to honey oil in minutes” on the website. This was the first time butane was mentioned as a solvent for cannabis extraction, and Gurung even patented his Oil and Fat Extraction Apparatus. What Gurung didn’t foresee was the onslaught of accidents to follow the contribution of his dangerous procedure.
Disclaimer: Don’t try this at home. Aside from being illegal, it is EXTREMELY DANGEROUS and should only be performed by trained, experienced professionals in the proper setting with adequate safety precautions (e.g. ventilation and fire suppressant controls, etc.) in place.
Open Blast Era
Much of the cannabis industry’s heritage has lent itself to danger, be it raids or jail time. But liquid solvent extracts were unique due to the substance itself causing harm to the extractors involved in its creation. After Gurung contributed “Hash Honey Oil” to The Vault of Erowid, there followed a do-it-yourself BHO-making frenzy.
“Open blasting” refers to cannabis concentrates made without a closed-loop system, a process that protects extractors by keeping the solvents contained. As amateurs attempted to create BHO concentrates in their homes, they would expose butane fumes to the environment of their makeshift lab, often causing explosions leading to serious or fatal injuries.
In addition to being extremely dangerous, homemade apparatus are also much less efficient. Even though open-ended systems can be assembled with relative ease, in the long run they’re more expensive than a closed-loop system. It would take 80 standard-size canisters of butane to extract 5 pounds of plant material, as opposed to the 32 canisters it would take in a closed-loop system. Dollars and cents aside, blasting is extremely dangerous and without the correct equipment, a recipe for an explosion.
Moreover, those that did survive creating their homemade BHO often rendered “poop-soup,” a nickname for low-quality extracts, filled with highly toxic mercaptan and uneven consistency. When these extracts made it to market, consumers had no idea what they were getting. These oils were surrounded in mystery and had unknown contaminants, namely residual butane.
Safety and Regulation
The innovation of BHO continued to take root, and soon extractors began using the appropriate equipment to prevent butane fumes from interacting with the environment. Closed Loop Extraction changed the game for butane hash oil. More cannabis companies outfitted their facilities with closed-loop machines, and today most legislators have made closed-loop production a requirement for licensed cannabis manufacturers.
These days, much of the cannabis industry is airing on the side of caution when it comes to residual butane in extracts. While butane is Generally Recognized As Safe (GRAS) by the U.S. Food and Drug Administration (FDA), most states have set their own residual solvent limits. Although states such as Washington have a limit of 500 parts per million, most extractors easily purge the solvents well below that limit. Municipalities set in place safety measures as well. In Colorado, Butane Hash Oil extraction can only be done inside of rooms that contain the proper ventilation and fire suppression controls to ensure the safety of their technicians.
Since coming out of the caves of open blast era, extractors have installed closed-loop systems to ensure safety and efficiency. Still, butane is highly flammable, and extractors should take precautions to ensure no harm comes to them during the process.
How BHO is made
WARNING: THE MANUFACTURING OF BUTANE HASH OIL AND OTHER CANNABIS CONCENTRATES SHOULD ONLY BE PERFORMED BY EXPERIENCED LICENSED PROFESSIONALS AS THESE PROCESSES CAN BE EXTREMELY DANGEROUS.
For safety and health reasons, producing extracts is best left to professionals, as the setup and materials are expensive and require precision and accuracy. It’s important to know how concentrates and extract are made to find the right cannabis products for your needs.
All cannabis concentrates come from a series of separation and purification. The idea is to isolate the nonactive elements of the plant from the elements that produce flavors and effects. Basic BHO extraction operations run through various cycles of refluxing, purging, and collection.
Preparing the starting material
Theoretically, any part of the plant can be used for extraction as long as it has trichomes. Technicians most commonly use trim or whole buds. BHO derived from whole flower result in extracts with richer flavor and higher potency, pulling cannabinoids and terpenes from the areas where they are most abundant.
The most important thing to keep in mind when sourcing the starting material is the percentage of water in the buds. Most of the flowers available at a dispensary average 6 percent water by dry weight. Plants for solvent extraction typically need to be less than 1 percent.
There are three main types of starting material: Live Resin, Nug Run, and Trim Run. Live Resin indicates the flowers are newly harvested and flash frozen to trap any terpenes that would be lost during the drying stage. Nug Run are flowers that have been thoroughly dried and cured after harvest. Trim Run consists of the leftover parts of the cannabis plant after the initial trimming. Trim Run is considered the lowest quality starting material, with Nug Run and Live Resin being of higher quality.
Introducing the cannabis to solvent
When it comes to deriving the properties of cannabis with butane, extractors apply their own spin on the same fundamental process.
Extractors pack the starting cannabis into the material column, a tank inside the closed-loop system that is dedicated to holding the nugs or trim throughout the process. The tank must be purged of any oxygen prior to passing the butane through to ensure that there is no explosion and unnecessary pressure.
The butane is chilled, then passed through the starting material, releasing the trichomes from the plant. To remove the butane from the solution, heat is applied to the combined mixture of cannabis and butane, causing the butane to turn into a vapor and rise into the solvent column.
As the vapor reaches the solvent column, it is cooled and condensed back into a liquid.
Some concentrates undergo additional processes, such as charcoal washing or additional wash cycles with other solvents, to render a purer product.
Residual Gas Removal and Different Textures
When ready, the extract is poured into a pan and placed into a vacuum oven to purge any residual butane. BHO extracts develop their texture during the purging process, which is shaped by time, temperature, pressure and agitation.
Extractors must always pay extra attention to temperature. Too much heat can ruin an extraction. Heat evaporates volatile terpenes that give cannabis its aroma and flavor, and triggers decarboxylation, which rids the concentrate of its translucent appearance and turns it into a darker oil.
The first purge is conducted with a vacuum pump, and when completed, it will not look anything like the liquid consistency that was poured into the tray.
Extractors use a pump to create a vacuum within the oven to manage “loafing” and heat to expel residual solvents. Loafing refers to the point when the extract rises, just like bread with a lot of yeast would. It happens when the pressure inside the oven drops and the temperature increases, causing the butane to boil out. If the material boils at a rapid pace, there is too much butane in it, and it is not ready to remove from the oven. Extractors want the bubbles in the extract to pop on their own, the goal being to have them as sparse and large as possible. Bubbles with walls too thick to allow the butane to escape will need a slightly higher temperature to decrease the viscosity of the oil.
Shatter has been considered, by some, to be the highest tier extract. To get BHO in the consistency of Shatter, the material must be placed in the vacuum oven for a long period at a low-heat setting. The oven should be around 98 degrees Fahrenheit (about 36.67 degrees Celsius) and at least -28inHg (inches of mercury) pressure for anywhere between 24 to 36 hours. During this time, extractors typically flip the slabs over at least once throughout the process. By the time extractors reach this stage, there are only traces of butane left in the final product.
Crumble can be made by whipping the BHO under the presence of a heated surface or when the BHO solution is placed in the vacuum oven between 110 and 135 degrees Fahrenheit (43 and 57 degrees Celsius) for 24 to 72 hours.
Badder requires higher temperatures and agitation. Place the slab in the vacuum oven at 115 to 140 degrees Fahrenheit (about 46 to 60 degrees Celsius) and whip the solution after it has been removed from the vacuum oven.
BHO Sauce is the not made using the same method that is typically applied to BHO extracts; 10 to 15 percent of the initial butane used to make the extract is left in the solution and stored in a pressurized vessel to allow the cannabinoids to start forming into small crystals. The heat and pressure applied can vary greatly among technicians.
How to store BHO
When stored improperly, BHO can begin to break down and lose its initial consistency, flavor or potency. To prevent this degradation, extracts should always be stored in an airtight and light-proof container in a cool environment. To ensure that the BHO keeps for as long as possible, protect it from High temperatures, Moisture, Oxygen and ultraviolet and direct sunlight.
Remember, heat is the enemy. It causes the cannabinoids and terpenes to activate, and that should only happen upon consumption — not while it’s resting in a container. Dispensaries, smoke shops, and many online stores offer concentrate storage accessories, such as silicone containers, to store BHO.
How to consume BHO
Like other cannabis products, there are a variety of ways to consume BHO. Referred to as “dabbing,” this method involves a small water pipe called a “rig” with a flat bowl, called a “nail,” that’s designed to tolerate high temperatures.
To take a dab, preheat the nail with a small gas-powered torch until it reaches the optimum temperature. Using the flat end of a dabber, drop a small piece of BHO onto the nail. When the shatter comes in contact with the hot nail, it will vaporize instantly. Place a cap over the nail to capture the vapor and inhale through an opening on the opposite end of the rig.
Similar to devices utilized to smoke nicotine-based products, handheld apparatus can be used to enjoy BHO. With these devices, a small amount of shatter is put into a heating chamber. The device is activated usually by pressing a button. The chamber is heated by a battery and the BHO is vaporized. At the same time, you inhale through the designated mouthpiece and breathe in the vapor.
Twaxing refers to when Shatter is rolled into a string, then wrapped around a blunt or joint of flowers for extra potency. Crumble isn’t limited to just dabbing either. It can be used as a potent “topping” for a bowl of flowers or even inside a joint or blunt.