The Butane-CO2 divide
Hash Oil. Dabs. Wax. Sugar wax. Distillate. All terms that are often used interchangeably – from newsrooms to living rooms.
They are all concentrates, but they are different.
In the past several decades, concentrates have gained huge followings due to their many benefits, namely convenience and potency. There is a significant concentrates culture all its own and many consider them to be the future of cannabis industry.
There is a great debate surrounding the two main concentrate extraction processes – Butane (BHO) and CO2. Both are used as solvents in the extraction process but there continue to be myths that contribute to misinformed positions in this debate. To objectively evaluate the processes, lets start with a few definitions:
Solvent: A solvent is something used to dissolve something else. The role of solvent in extraction is to strip the cannabinoids, terpenes, waxes, lipids, and other chemical compounds from plant material
Crude (or Wholesome plant extract): the resulting solution containing cannabinoids and terpenes from the separation process
Winterization: is dissolving of a nonpolar substance (hash oil) into a polar solvent (most commonly ethanol) at sub-zero temperatures. The temperature of this solution is then dropped very cold. This process separates the waxes and lipids from the oil, forcing them to collect at the top of the mixture for easy filtration.
Fractional distillation: The targeted individual extraction of cannabis compounds
Terpenes: Any large group of volatile unsaturated hydrocarbons. Wow. That sounds dangerous but they’re not – they’re present in all plants. Cannabis contains its unique terpenes. Each cannabis strain contains a unique terpene profile depending on the concentration of different terpenes present .
Hash Oil: The base from which wax, sugar wax, or shatter can be created
Dab: A concentrated marijuana extract
Purging: The process of removing volatiles
Budder or Wax: Tends to be completely dry and crumbly and is sometimes referred to as “honeycomb” because of its resemblance. After the solvent runts through the flower, the resulted extract is then placed in the vacuum oven that purges it using heat and vacuum (negative air pressure). Wax/crumble get’s it’s texture from being purged for longer at higher temperatures. But because it is over-purged the final product is missing an ideal component, the natural terpenes.
Shatter: on the other hand, shatter is not over-purged and it keeps high terpene concentrations. “Dewaxed” shatter is free of solids that could impart a cloudy appearance and will leave little residue behind when vaporized. It tends to have a consistency ranging from sticky sap to a very stable, hard resin at room temperature. The color can range from dark brown to a nearly translucent.
N-Butane is the highly purified solvent used to produce BHO.
Imagine you are walking into a room with stainless steel tanks and pipes them. That stainless contraption is an extractor and you are in an extraction room. Here producers use gases like N-butane and N-propane to strip the essential oils and compounds from the cannabis plant. Hydrocarbon extraction rooms use sensors and high tech ventilation systems to ensure vapors of these gasses can never reach flammable levels in the air, keeping everyone in the facility safe.
The extraction process begins when flower is loaded into what’s called an extraction vessel where a blend of liquefied hydrocarbon gases (HG) are run through it.
The result is a mixture of solvent and oil. It is then separated when the solvent boils and evaporates. Virtually all of the butane that was run through the flower is recaptured to be reused in subsequent extractions. Once the solvent is recovered, the oil is ready to go in the vacuum oven. At this point the compound is foam-like but sets after a few minutes. The vacuum oven is used to remove any possible remaining butane solvent through a process called purging.
In the oven, temperature and pressure can be manipulated to produce different products. These can be shatter, budder, sugar wax, sauce, or diamonds!
When the process is complete, the extract should not contain any measurable amount of solvent if done with the proper procedures and are just as safe as products made with other forms of extraction. These solvents are also excellent at picking up terpenes and leaving behind much of the unwanted waxes and lipids. Users report superior flavour and the test results show that these concentrates have a higher purity than products made with Co2 extraction or with other solvents.
CO2 extraction is often used for producing oils we enjoy in vaporizers, edibles and topicals. It can also be used to make high terpene extracts! However, it’s not often used for making dabs. It does, however produce oil with a high wax content, which means that most Co2 oil used for vapes needs to be purified using alcohol in a step called winterization which we will explain below. C02 extraction was once considered to be a more environmentally friendly method than butane, but now with closed extraction loops, the butane (or propane) is captured and repurposed with little to no waste and Co2 extraction does consume more energy.
As with the butane process, the CO2 extraction process starts with raw material (flower) being soaked in liquefied CO2. Using different pressures and temperatures,the solvent can be made to target different compounds, such as terpenes or cannabinoids like THC-A and CBD. This is the most significant difference compared to butane extraction: the ability to separate desired compounds straight from the raw material as opposed to extracting all the compounds in one and then separating compounds out of the resulting concentrate.
On the steps of greatness
When making distillate, the steps are the same for both CO2 and butane extraction. The crude oil goes into a secondary phase called winterization. Essentially, winterization is a process of mixing the extract with alcohol and then placed in the freezer overnight. The sub zero degree environment will allow the waxes and fats to separate from from the good stuff. The mixture is then filtered and the alcohol is evaporated and recaptured.
This oil is now ready to be made into distillate. In this process, the cannabinoids are evaporated and then condensed, which purifies the oil each time. The result is a golden, honey like material that contains 85-95% cannabinoids.
In the end
Closed loop extraction systems made both butane and CO2 safe and reliable. So, which one to choose? A common misconception is that C02 oil is solventless, while BHO is not. Carbon dioxide is a solvent just like butane. No extraction method is best for all purposes but they all have things that they are great at.
BHO (butane hash oil) can take the form of wax, shatter sauce and diamonds. When it comes to flavor, BHO is widely regarded as the superior choice by many dab enthusiasts because it extracts almost the entire terpene profile and it results in a product high in THC and low in waxes.
The downside of CO2 oil is that is generally more expensive and weaker than BHO which mean it usually needs to be winterized with alcohol or distilled before its good for vapes or dabs.