cannabis rosin solventless hash oil

Rosin: A Solventless and Inexpensive Way to Make Your Own Cannabis Extract

As a cannabis grower, consultant and educator, I would consider myself a generalist. I do know a lot about the plant, and I also know my limitations.

There are specialists in the cannabis concentrate field, especially given that we finally can legally apply real science to the study of the plant [many a PHd’s will be written about this plant in the very near future].

When I really want to get down to the nitty gritty specifications of individual topics in cannabis concentrates, I consult experts in those areas.

For this article on rosin technology, I reached out to my friends at PurePressure who specialize rosin press technology. Here’s what they had to say.

What is Rosin?

Rosin, also known as SHO (solventless hash oil) has blossomed in popularity over the last few years as one of the simplest, least expensive way to extract a concentrated blend of terpenes and cannabinoids from raw buds or hash using a method sometimes called “rosin tech.”

These cannabinoids and terpenes profiles, which create the aromas and flavors of cannabis, are a key target of extraction.

Rosin is a solventless process, meaning it relies on heat and pressure to squeeze cannabinoids and terpenes from the source material, as opposed to the chemical (solvent) process used to produce BHO.

For many consumers, the main benefit of this solventless process is that it does not contain the residual hydrocarbon often found in solvent extracts.

How is Rosin made?

The science behind rosin is simple: Applying heat melts the terpenes and cannabinoids into a pliable resin. Then the resin is squeezed using a press.

This efficient isolation of terpenes from chlorophyll and plant lipids offers a flavorful profile, one that is almost impossible to replicate by smoking or vaping raw buds.

One of the solid advantages of rosin is the speed and ease of extraction: A tasty and potent batch of rosin can be produced in moments and consumed immediately using inexpensive equipment and minimal risk of physical injury.

Note: You must be careful about screening material for mold, residual pesticides, and other contaminants. They stick to the resin and become concentrated in the process. Bottom line: It’s crucial that you ensure clean, high-quality source material, whether you’re pressing rosin from trim, buds, or hash.

There is a bit of a learning curve when using a rosin process at home. This is due to some of the lipids and waxes melting at the same temperatures.

This results in the finished product generally not being as refined as material produced using solvent-based extraction methods.

But with training and experience, the end product can rival solvent extracts.

Today, solventless cannabis products can be found in everything from CBD oil to THC topicals or capsules, edibles, tinctures, vape cartridges and much more.

What is the difference between rosin and BHO?

BHO (Butane Hash Oil) is a hydrocarbon extraction method using the solvent butane to make shatter, wax and sauce extracts.

The initial process of butane extraction is to “run” butane through raw cannabis buds to dissolve the cannabinoids, terpenes, and other active ingredients from the plant matter, then evaporate the solvent.

What’s left behind is highly concentrated resin with trace amounts of solvent. That solvent is then purged, using additional step(s).

The purge process may depend on a number of factors: the physical qualities of the plant matter used; the quality of the resulting resin and the desired end product—shatter, wax, sauce, etc.

A concern for many consumers and medical patients with solvent processing, is the potential for residual hydrocarbons remaining in the product even after is has been purged.

That said, there are some health benefits to hydrocarbon extraction, namely that it strips away or neutralizes biological impurities including bacteria, mold, and other contaminants.

Additionally, the start-up costs of this method are very high compared to a solventless extraction: The cost of the safety equipment needed, and laboratory modifications, exceeds the cost of even an elaborate large-scale rosin operation.

Solventless products are often regarded as the superior product for medical and palliative purposes

Clean, solventless concentrates eliminate any risk of other compounds or chemicals interfering with a patient’s treatment

Concentrates tend to be associated with the recreational aspect of cannabis consumption.

While it is certainly true that concentrates are consumed for recreational purposes, the perception that they are linked ONLY to the recreational market limits the number of consumers willing to explore solventless extraction equipment, rosin or other solventless concentrates.

Only recently have solventless concentrates begun to receive attention within the medical community.

Unlike other concentration methods, patients have the assurance that a solvent-free product contains only material that came from the plant.

This minimizes risk associated with other compounds or chemicals that may interfere with a patient’s treatment.

The potential of cannabinoids for medical patients

Close up of cannabinoid full trichomes on a cannabis bud. The higher the cannabinoid content of your starting material, the higher yields you can expect. For the best rosin, press the best buds. Freshly cured, resin-rich material results in the best rosin. It is rich in terpenes and high in cannabinoids. Small buds and trim can also be pressed into rosin.

CBD and THC certainly deserve the attention they receive, but there are many other raw, acidic forms of cannabinoids that offer several of the same benefits of the decarboxylated form, but with reduced intoxication.

It’s important to understand the difference between raw and “activated” cannabinoids, because they have different properties and impacts.

Many people don’t realize that the vast majority of what’s contained inside the cannabis plant’s resin glands is THCa, the chemical precursor of THC. The same is true for CBD: High CBD strains are actually high in CBDa.

In both instances, the “a” stands for acid — carboxylic acid specifically, which does not easily pass through the blood-brain barrier because of its atomic structure, which is altered passively through the process of decarboxylation; the name refers to the removal of the COOH “carboxyl group.”

Although people generally refer to the total measured potency of a flower or concentrate (including acidic precursors) as “cannabinoid content,” it’s the raw cannabinoid acids that are dominant in bud.

Smoking, vaporizing, or in some cases extracting the bud decarboxylates THCA to delta-9-THC, the psychoactive compound, or in the case of cannabidiol (CBD), from CBDa to CBD.

Rosin processing, though not a cold process, occurs below the volatilization point for most of the terpenes, and doesn’t reach the temperatures needed for decarboxylation, preserving the raw, acidic cannabinoids so the rosin is mostly a concentration of THCA and/or CBDA, the acidic precursors to the cannabinoids.

The result: if consumed at this point, the material is not intoxicating and will preserve the acidic cannabinoids.

Many patients find great relief in combining both acid cannabinoids and activated cannabinoids.

This is why rosin presses are growing in popularity due to their tasty profiles, and their ability to create THCA separations and other cannabinoid-specific products.

Here’s all you want to know about rosin, AKA as SHO (solventless hash oil): What is rosin? How is rosin made? What is the difference between rosin and BHO? And more.

The many types of solventless cannabis extracts

The world of cannabis extracts is expanding rapidly with no intention of slowing down. In most legal markets, concentrate sales are increasing steadily as they continue to grab larger shares of the market year over year. Emerging trends within cannabis concentrate sales have undoubtedly fueled innovation at a staggering pace as a result of high demands.

Explore cannabis concentrates

For consumers, this is indeed a very exciting phenomenon. Fans of hash products would agree that having options available is paramount. Yet only a few years ago, if you wanted to purchase cannabis extracts that were produced without the use of chemical solvents ( e.g, butane, propane, etc.), your only options were kief, cold water hash, and, in some rare cases, an old world pressed hashish.

It wasn’t until recently, with the emergence of new advancements in heat extraction methods, where the market began to shift back in favor of the solventless hash consumer. Interest in heat extraction methods such as rosin proved to cause a profound effect within the community by reinvigorating the appeal for solventless extract innovations within legal markets, thus giving way to an entirely new generation of hash products. This rift in the cannabis concentrate paradigm can perhaps be measured most accurately by the sheer increase in solventless options available to consumers today.

What follows is a brief overview of a few solventless options that you may not be familiar with but might be available at your local cannabis retailer.

Rosin and solventless shatter

Rosin, being the game changer that it was, opened the door for several different new products. Solventless shatter, a type of rosin that maintains a stable and glass-like consistency, may resemble butane hash oil in appearance but was manufactured with nothing more than heat and pressure. Hash oil of this consistency is achieved both through the acquisition of certain genetics and the right combination of heat, pressure, and exposure period.

Some cannabis cultivars will produce more stable rosin than others. Cure time and degradation of the trichomes also greatly affect hash oil consistency in the rosin form. Rosin can be made from a multitude of precursors, including freshly harvested and/or cured cannabis flowers, kief, water hash, and even trim. The color, consistency, and flavor profiles will all vary considerably depending on the precursor used.

Many solventless hash oils are offered in more sappier and less stable forms. Their color can also vary from a golden opacity to a darker amber. Cure time and starting material will all play a role in facilitating these nuances. Heat, pressure, and exposure too can greatly impact the consistency of rosin. Higher temperatures tend to produce more stable products that more resemble shatter, whereas lower temperatures often yield sappier, less stable products. Both products are appearing on dispensary shelves and have begun to form respective niche markets.


Another variation of solventless hash oil is budder, also known as cake batter or a “whipped” rosin. These products were created by incorporating light heat and agitation to rosin. The result is a buttering effect that looks very similar to a salve or batter of some sort. Using this technique has been known to significantly increase the aromatic properties of the hash oil and also provide a new creamier texture that can be much easier to work with when dabbing. While many retailers are beginning to sell whipped solvent-free hash oils, the process can be achieved easily at home with preexisting rosin by simply stirring it consistently with a warm dabber tool.

Freeze-dried hash oil products

On the polar opposite end of the thermal spectrum are new products incorporating the use of sub-zero temperatures in their production. Freeze-dried hash oil products are made by utilizing sub-freezing temperature to keep trichomes in a perfectly suspended state in their degradation cycle, thus preserving valuable and volatile tepidness that would have been lost in almost any other extraction process. The machines used to create these products can be expensive, as this technique is still relatively avant garde,

As the concentrate market continues to expand, demand for solventless options will continue to inspire innovators to push the envelope even further in creating more exciting products for hash consumers. Rosin, and its many subsequent forms, was the Pandora’s Box that opened up the door for full melt hash oils, and the demand only seems to be rising. Expect to see many more products emerge that will inevitably push the boundaries of hash oil flavor, consistency, and effect even further. Long gone are the days where the only products available to concentrate enthusiasts were limited to BHO, kief, and bubble hash. Hopefully all of these options come to your area soon so you can partake in these new solventless options!

Brush up on our brief overview of solventless cannabis extract options that you may not be familiar with but might find at your local cannabis retailer.