From Soil to Oil

The Technologies Behind Cannabis Extraction and Infusion

Not that long ago two of the most common ways for cannabis consumers to enjoy their weed was by either smoking it or eating it – and often eating it meant swallowing home-made, gritty and not-very-good-tasting brownies, cookies and other baked goods. But years of covert tinkering by potheads, agricultural students, biochemists and others, along with the rapid state-by-state spread of legalization, has created a multi-billion-dollar industry not only for cannabis but also for cannabis extracts and infused products.

According to a report released last year by Arcview Market Research and BDS Analytics, sales of cannabis concentrates in the United States are estimated to reach $8.4 billion by 2022 – and those concentrate sales are expected to come close to matching sales for flower.

Steve DeAngelo, a cannabis activist who’s also co-founder and chairman emeritus of the Oakland, California-based Harborside cannabis chain, told DOPE that vape pens alone now account for around one-third of sales at many dispensaries.

“And that’s a product category that didn’t really exist five years ago,” he says.

Thank Mother Nature for Trichomes

In terms of extraction, “Mother Nature was very kind to us when she designed the cannabis plant,” says DeAngelo.

Most of the active ingredients in cannabis, he explained, including the ones containing the plant’s psychoactive, aromatic and therapeutic properties are contained in trichomes: the sticky crystalline structures that sit on the plant’s surface.

“The point of every extraction method is to detach the trichomes from the underlying vegetable material,” he continues, “taking away as little of the underlying vegetable material as you can.”

Here are some of the better-known extraction methods.

C02 Extraction

“C02 is carbon dioxide, what you exhale,” says Christopher Moder, a biochemist and product development specialist at Dixie Brands, a well-known producer of THC and CBD-infused products.

C02 extraction is not a new science. It’s been used for decades to create decaffeinated coffee.

The process involves taking canisters of the gas and pressurizing them into a supercritical state – which means the C02 is now more of a liquid than a gas. Once it’s heated, Moder added, the pressurized C02 “starts to work more like water or any other solvent.”

The pressurized, heated and liquefied C02 is then added to finely-ground cannabis. It creates a cannabis “tea,” which like regular tea steeps for a while in the solution before being pumped out into different extraction chambers at different temperatures – to create a variety of extracts with differing qualities (from powders to a taffy-like concentrate) and different oil content, aromas and potencies.

C02 is a very clean, environmentally-friendly and effective way of extracting cannabinoids, but typically it is just the first step of the extraction process. Additional steps, such as an alcohol wash, are also needed. Those second-phase extraction processes also strip out much of the plant’s terpenes, the organic compounds that give marijuana its flavor and that reportedly have some beneficial properties. The majority of those terpenes can be put back into C02-extracted concentrates if needed, for example, to give vape pen oils their appropriate flavors.

And as DeAngelo notes, “there are many people who like C02 extracts for edible cannabis; because when it removes the terpenes, it also removes some of the flavor challenges that you have with other types of cannabis extracts.”

Butane Extraction

Hydrocarbons are the leading compounds found in petroleum and natural gas. And the hydrocarbon most often used for cannabis extraction is butane, which is relatively inexpensive but highly flammable.

When used as a solvent in a pressurized heating system, butane can be a very effective way to concentrate both terpenes and cannabinoids – creating a full-spectrum extract that can be used in vape pens, RSO or dab rigs.

“It tends to have a higher yield than the C02,” says DeAngelo. “but the capital investment in a safe and effective butane extraction facility is significantly more expensive than in a C02 facility.”

Ethanol Extraction

Alcohol has been used for millennia as a solvent in the production of essential oils and tinctures. It is also very effective as an extraction medium for cannabis.

But ethanol alcohol, which is commonly used in alcohol extraction, has properties that cause it to extract water-soluble components such as bitter-tasting chlorophyll, along with the desired cannabinoids and terpenes from the cannabis plant.

As a result, those using ethanol alcohol as an extraction method often need to add additional refinement and purification processes to make their end product clean.

Water Extraction

One of the most natural extraction methods involves putting cannabis into very cold water, sometimes with ice, then agitating the mixture and screening out the vegetative materials.

“There are many cannabis connoisseurs who prefer that kind of extraction,” says DeAngelo, “because like butane extraction it has a very rich terpene profile and a high level of potency, although not as high as butane.”


Cannabis-infused edibles and beverages are one of the fastest-growing parts of the cannabis industry, and there’s a very strict science when it comes to ensuring that the cannabinoid content is evenly distributed throughout those products.

According to Scott Riefler, chief science officer at SōRSE Technology in Seattle, it’s not just a matter of “dumping the (cannabis) oil in … putting it in a blender and hoping that everything distributes.”

Even distribution can be especially difficult in cannabis-infused beverages – where manufacturers are required to ensure that the consumer is getting the same amount of THC or other cannabinoids in each measured amount.

This problem isn’t unique to the cannabis industry, however. It also applies to store-bought oil-and-vinegar salad dressings or popular cappuccinos-in-a-bottle. The solution, like in those commercial products, involves the use of emulsifiers: additives that stabilize and evenly distribute the cannabis infusion in the beverage or dried product.

New Technologies Coming Online

Riefler tells DOPE that there are new technologies, such as more water-compatible emulsions, that are changing the face of the infusion industry. And scientists are also working on ways to make consuming cannabis more like drinking a beer – with the intoxication taking effect within minutes of consumption and then wearing off in 90 minutes to two hours.

“I’m of the belief that once this market gets to a place where a major consumer company gets involved, you’re going to see these new technologies exploited on a large scale,” he says.

For his part, DeAngelo believes we are only at the beginning of what he calls a cannabis renaissance when it comes to exploring the science of cannabis edibles, infusions and extractions.

“We can look forward, as cannabis consumers, to seeing really a parade of […] innovations and new products and new formats coming online over the course of the next couple of decades,” he says. “Because cannabis has been illegal since the birth of modern technology … there’s just a vast arena for that technology now to meet this ancient plant.”

Bruce Kennedy

Bruce is an award-winning communications professional and multi-media journalist who has years of experience in nearly all aspects of international and business news. He’s been covering the legal cannabis industry since 2010, and has written for a wide variety of U.S. and international news outlets.

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