In the increasingly crowded market for cannabis concentrates, a new category has emerged: Solventless extractions.
Some patients and recreational consumers concerned with health issues are beginning to show a preference for concentrates made without potentially harmful solvents like butane and CO2. Such extractions utilize processes involving heat and pressure and can be performed with a wide range of equipment, from bathroom hair straighteners and flat irons to industrial-grade laboratory gear.
One increasingly popular example of a solventless concentrate is rosin, sometimes called “rosin tech.” Rosin is rapidly gaining popularity for several reasons, the biggest arguably being that it can be produced safety at home using common cannabis flowers. While flowers from cannabis strains range in THC potency from about nine percent up to 25% or even 30%, concentrates like rosin may be up to 80% THC. Some concentrate enthusiasts have claimed that rosin will be “the death of BHO [butane hash oil].”
According to Mat Lee, a concentrate connoisseur in Washington State who often writes and podcasts on the topic of concentrates:
“The one thing people keep saying is that the taste [of rosin] is phenomenal, and the amount of work you put in for the quality you get out is also pretty nice.”
Homebrew Hash Oil
Put simply, rosin is a cannabis resin extraction method that utilizes heat and pressure to produce a hash oil concentrate that is completely free of harmful solvents. The good news for curious cannabis consumers is that this heat and pressure doesn’t have to be derived from expensive, industrial-grade laboratory equipment. Instead, one needs nothing more than some parchment (wax) paper and a common hair straightener (any flat heat press mechanism will work). Some users report a 25% yield using a $20 hair straightener (a yield is quantified as a percentage of the weight of the original herb or kief used as the extraction source).
Technically, the extraction of rosin combines heat and pressure to melt the bulbous, resinous heads of trichomes found mostly on the buds and sugar leaves of the cannabis plant. Rosin can be extracted from cannabis flowers (buds), kief, or hash.
According to Errlax, a hash and concentrate expert in Colorado, rosin is “a solvent-free hash oil product that rivals hydrocarbon extractions in aroma, aesthetic, and—most importantly—medicinal efficacy.” The process of extracting rosin using a common hair straightener can be performed in as little as three minutes. Errlax adds:
“In the end, this technique is a game changer.”
Within the past few years, the media and conservatives have repeatedly had the opportunity to lay valid criticism at the cannabis community and black markets for backyard BHO operations run by two or three sloppy schleps that resulted in a life-threatening explosion or fire.
One infamous case in Bellevue, Washington, where three young men were producing BHO in their apartment, produced a building fire that resulted in multiple deaths, including that of Bellevue’s 87-year-old former mayor, who jumped from a multi-story window to escape the flames. This travesty also produced many injuries and millions of dollars in property damage.
“The last thing we need is a rash of articles in the mainstream media demonizing dabs because people can’t seem to not blow themselves up trying to make them.”
Concentrates like BHO and CO2 oil are much healthier for patients and also perfectly safe to produce when processed by trained technicians using industrial laboratory equipment.
However, homebrew concentrate operations, in which a few people use common kitchen or garage items and a highly explosive solvent like butane, are a totally different ballgame. The issue isn’t as simple as BHO being healthy or not. Production techniques and equipment are critical to the purity of the final product and its resulting health implications.
Health Concerns / Black Market Bingo
All cannabis consumers, particularly patients, should be concerned with the health issues regarding their herbal medicine and concentrates, especially if those extractions are created using potentially harmful—and highly explosive—solvents like butane. By utilizing a solvent-free process, the question of residual chemicals and their potential damage to one’s health becomes moot; one needn’t be concerned with a residual substance that was never there in the first place.
One tremendous advantage of rosin, despite its unpredictable quality and potency, is the fact that it can inexpensively be made at home. This helps guarantee that patients and lifestyle users alike are getting safe, clean concentrate, not some black market gak produced by unscrupulous cartels or sloppy amateurs that may contain high levels of residual solvents, fillers, or other contaminants. Those in prohibitionist states have no choice but to dip into the black market for products like BHO.
According to Oregon’s The Weed Blog:
“…if someone doesn’t evaporate (or purge) their butane hash oil properly, there can be quite a bit of undesirable stuff that people are now smoking.”
Although these same patients and users must also shop the black market for flowers and kief, the quality and predictability of cannabis buds is typically much greater than for exotic concentrates like BHO (also known as honey oil in parts of Canada and the U.S.). Those who produce their own rosin from reasonably potent flowers using a process like the application of heat and pressure avoid the fear, uncertainty, and doubt of the black market.
Versus Live Resin
Rosin and live resin are two of the most promising new developments in the world of cannabis concentrates. While live resin offers the advantage of almost perfectly preserving the terpene profile of whole plant cannabis and delivers great aroma and flavor, it also requires industrial equipment to cryogenically freeze plants directly after harvest and expensive closed-loop butane and CO2 extraction machines.
While this laboratory equipment typically is capable of removing the vast majority of solvent from the final product, the fact that something like butane is used at all concerns some users—especially those who indulge on a daily basis.
Rosin is like live resin’s provincial cousin, a solventless rural roughian that produces highly variable results and will completely destroy most terpenes (those that feature a boiling point below 310 degrees F [154 C] are destroyed by most hair straighteners). Live resin, on the contrary, offers the advantage of terpene profile preservation, but also involves solvents (albeit using professional equipment). In this respect, the two concentrates are very different. Both processes produce a high quality “full melt” hash oil.
Yields and Quality
Because inexpensive, common equipment such as a hair straightener can be employed to extract rosin from cannabis flowers, the results can be less than optimal. For example, for what length of time should one apply pressure to a sample of flowers? What is the perfect temperature for a device like a hair straightener or iron? Should one make multiple passes over a single sample of flowers? Unfortunately, the only way to accurately gauge the temperature of the pressing element is to use a temperature gun.
One user reported producing 0.45 grams of rosin from two grams of cannabis flowers. This was done employing pressure and a flat surface at 300 degrees F (149 C), with two passes of 10 seconds each. Theoretically, there is an ideal length of time and amount of pressure necessary to produce the maximum yield of rosin from a given quantity of flower or kief (which will themselves vary in quality and consistency). Because it is typically laypeople indulging in the creation of rosin, they often lack the knowledge or experience to perform the exercise and achieve the best results.
One instructional video provides a hands-on demonstration of creating rosin that employs a hair straightener set to 400 degrees F (204 C) and brief applications of pressure for only two or three seconds each. This video also provides a good example of vaporizing a concentrate like rosin using a dab rig (this particular rig employs a titanium nail). This tutorial shows just how quickly one can create full melt, potent rosin suitable for smoking or vaporizing.
Due to the magic of modern social media and video repositories like YouTube, curious consumers can quickly learn the ins and outs of the process to produce relatively satisfying results without wasting their precious herb on a botched extraction job.
Before running out and purchasing a hair straightener at the local beauty supply store, one should consider the pros and cons of rosin and if it’s worth producing on a regular basis. Herb isn’t free or easy to grow, after all.
The rosin process, which does not scale up to industrial levels very well, may be worth the time and effort for individuals, small groups of friends, or patient collectives that really enjoy or depend on concentrates—but live in prohibitionist states lacking dispensaries and don’t want to play black market bingo or risk their health on a residue-laced cannabis oil of questionable quality. This is especially true for very sick patients.
Errlax stresses that household rosin collection techniques will never produce top-shelf product due to how such efforts destroy most terpenes and can even damage cannabinoids and flavonoids (the botanical molecules responsible for flavor).
“This technique, like CO2 extraction methods, doesn’t do well in preserving complete profiles. You will lose part of the desired entourage effect that the full profile of the flower creates.”
Lure to Experiment / Tips
Many will inevitably give in to the temptation to use something as common and affordable as a hair straightener to quickly and easily produce a potent cannabis oil featuring great aroma and taste. Those who value terpenes and wish to preserve them should seek out live resin or leading-edge solventless extraction concentrates that employ low heat or other techniques.
Some tips for producing rosin:
- Unlike smoked or vaped cannabis, freshly harvested buds work best. The higher the moisture content, the better the results.
- Fold the parchment paper over itself to create an open envelope for the buds or hash and press down, with both arms and one’s full weight, on the hair straightener or iron.
- Although rosin is a very new type of concentrate and much remains unknown, it is reported that certain strains are much better suited for its creation. Those who can’t afford to experiment may want to do some online research.
- The consistency of the final rosin will vary, especially given the highly variable nature of the buds and equipment used to create it. However, it should generally resemble a stiff shatter, a flexible gooey wax, or an oily residue. Colors cover a wide range based on flowers or hash used.
Given the very real danger imposed by amateur and criminal operations that produce concentrates like BHO in black markets, rosin offers a safe and solvent-free option for marijuana consumers who may want to introduce some variety to their diet of cannabinoids. It’s difficult to botch and affordable, especially for those in legal states where cannabis prices are lower. Those who decide they don’t like the results are, at worse, out an inexpensive hair straightener or flat iron and a bit of herb or kief.
The cannabis community has always embraced a libertarian, pioneering spirit of independence and self-reliance. Those who enjoy concentrates and find rosin attractive should purchase a half ounce of heady herb or wait for their next harvest and experiment with yet another avenue for the consumption of cannabinoids.
All content Copyright (c) 2003-2018 Gooey Rabinski. All Rights Reserved.
Gooey Rabinski is a technical writer and instructional designer who has contributed feature articles to magazines such as High Times, MERRY JANE, Herb.co, CannaBiz Journal, Twelve High Chicks, Grow, Emerald Magazine, Cannabis Culture, SKUNK, Whaxy, Heads, Weed World, Cannabis Health Journal, Green Thumb, and Treating Yourself. He is the author of Understanding Medical Marijuana, available on Amazon Kindle, and a contributing writer at .