Going back to ancient Greece, people have been using pressure to squeeze the oil and moisture contents out of olives to make olive oil. Musicians who play stringed instruments have also been using pine tree rosin to wax their violins and other similar instrument bows for hundreds of years.
Making Rosin from Cannabis
So what techniques are used to make rosin oil from cannabis? Typically, it involves the use of pressure from rosin heat plates attached to a pneumatic press to squeeze the plant oil contents of cannabis flower, dry sift, or water hash between a fold of food-grade parchment paper. By placing the input material in appropriate-sized nylon or stainless-steel filter bags made with specific micron hole sizes, we can successfully squeeze rosin extract oil out of many different forms of source material.
Many variables affect the quality and quantity of rosin that is extracted including pressure, temperature, squeeze time, moisture content, quality of source material, and which size filter bag is used. One of the most challenging and rewarding parts of rosin extraction is mastering how all of these variables change the final product, and for this reason, it is highly suggested to record as many of these variables and notes each time you squish rosin oil in order to maximize your knowledge and techniques for future extractions.
Although temperature and time vary, the general range is to practice rosin squishing at 170-210°F for 30-60 seconds, depending on the material and press being used.
The Benefits of Rosin
There are many attractive qualities of rosin, but a few stand out as consistent reasons people choose it. First and foremost, the complete lack of solvents used in the extraction process leads to a completely solventless extract.
Unlike butane, propane, and other extractions based on solvents made of volatile organic compounds (VOCs), which can only strive to be solvent-free, rosin extractions avoid the use of solvents. This is why the term solventless, instead of solvent-free, is associated with rosin-based extraction. This widely understood concept is one of the biggest reasons consumers find rosin easy to trust since it’s made by a physical process and not chemicals.
Another common attraction to rosin-based extraction is the simplicity and do-it-yourself nature of the process. It’s worth noting the first rosin extraction techniques that gained popularity were mostly homemade and DIY machines, ranging from hair straighteners and hardware clamps to heat plates, car jacks, and pneumatic press equipment.
The ability to make high-quality cannabis extract at home with simple equipment and processes is definitely one of the reasons many people have gravitated to rosin. Once the global cannabis market showed demand for rosin presses, there was a quick response from manufacturers and there was a selection of premade and manufactured rosin press machines on the market. Machines range from small 10-pound units that fit in a backpack to commercial units with 25 tons of pressure and 5x10-inch plates.
The recently expanding commercial market for CBD has even seen the development of gigantic rosin presses designed for hemp extraction of cannabinoid oils with 16x24-inch stainless steel plates that can press with 200 tons of pressure and squeeze a kilogram of dry flower at a time, enabling huge solventless workloads per day.
The last big reason people gravitate towards rosin is most likely the instant gratification that comes with the technique. Most other extraction techniques require a period of curing to remove moisture, or time in a degassing chamber or oven to remove solvents. Rosin extraction is ready to enjoy immediately, and for this reason, many people enjoy the tradition of fresh-squeezed rosin, and the ability to only make what you need for the immediate future.
Similar to freshly squeezed fruit juices or ground spices, rosin connoisseurs know that the fresher the squeeze, the more fragrant and intense the aromas and flavors that are present when enjoyed.
There are numerous accessories that can go hand in hand with rosin-based extraction. Dry-sift screens, trichome-drum rolling machines, dry-ice shakers, and cold-water bubble hash bags can all be used to create hash that is then squeezed for rosin-based oils.
Filter bags also come in many different shapes and hole sizes for a wide range of techniques and rosin presses. The most common material is nylon, but some are made of stainless steel and they really work well with trichomes.
Another fun machine to couple with rosin extraction is a freeze dryers. Previously only available on the commercial scale, there are now home-size countertop units that give access to plant material that is fresh, but still dry enough for rosin extraction. Freeze dryers are rapidly gaining popularity in modern hash techniques because they can safely remove moisture content without losing precious volatile monoterpenes present in fresh material.
Often overlooked, one of the byproducts of rosin squishing is the leftover plant material or hash in the rosin bags. Known as rosin chips, these leftovers still have valuable cannabinoids and often some leftover THC. It is prudent to save these chips in a clean jar and separate them from the nylon extraction bags when possible to create a resource for a second extraction. It’s possible to squeeze rosin chips again for a “second press” or save them to make edibles or tinctures.
Rosin extraction typically does not extract high levels of CBD, so the chips are usually a valuable source of leftover CBD.
Auto-Buddering and Rosin Shatter
High-quality rosin that is high in the raw form of THC, tetrahydrocannabinolic acid (THCA), and terpenes will often undergo a state change known as “auto-buddering.” This happens most often when rosin is exposed to temperature or humidity fluctuations. Rosin shatter will change from a crystal structure to small chunks of polycrystal budder. This is what is also responsible for the change from transparent to opaque coloration.
Although sometimes shunned, buddered rosin does not imply low quality, and can actually be used to make THCA crystal with an interesting technique involving repressing the buddered rosin in 15 or 25 micron-size bags at very low temperatures and light pressure to squeeze the terpenes and “sauce” out the THCA rosin.
Repeated light presses of slightly increasing time, pressure, and temperature at temperatures near 90-100°F while replacing fresh parchment paper between each incremental step will eventually squeeze out most of the high terpene sauce present in the budder. Once this is accomplished, the budder state will change, and raw THCA is then collected from inside the micron filter bag. Look for the white color and crispy chips to find the highest purity of THCA.
The solventless, high- purity THCA chips can be a popular ingredient for medicinal edibles, enjoyed as is, or recombined with the high terpene sauce to make solventless sauce and diamonds extract, but keep in mind that although it has been exposed to small amounts of heat, it’s not fully decarboxylized.
Read also: Solvent-free Extracts and Concentrates
Hash Rosin Gems
Another technique gaining popularity is combining heat and pressure to mage gems (and sometimes faceted gems or diamonds) by recreating the similar combinations of heat and pressure found in pressure cookers on a smaller and safer scale.
By starting with high-quality fresh frozen or freeze-dried flower, then collecting the trichome heads with the least amount of damage possible utilizing the cold-water bubble hash extraction, then freeze-drying the hash to safely remove moisture content without losing precious terpenes, the highest amount of terpene content with the least amount of plant matter and impurities is achieved.
The freshly freeze-dried bubble hash is then squished in a rosin press with 25-37-micron screens and then put into small food-grade preserving jars and placed in a controlled oven at temperatures ranging from 180-220°F for one to two hours.
These techniques require obvious experimentation, attention to detail, and note-taking, while making tiny adjustments in technique to see the different results. Many people like to look at the layer of bubbles on top as the rosin and terpenes separate to determine the cooking time in the oven. To preserve the pressure created inside the jar, a vacuum chamber heat mat is pre-heated to 90-110°F, and as soon as the jars come out of the oven, they are placed on the heat mat for one to four days (or longer depending on the material). The jars can be burped at various stages and with varying effects on the composition of the gems and facets.
Some other techniques to experiment with involve stirring, agitating, or even seeding the crystal structures with tiny amounts of very high purity isolate cannabinoid crystals from another source.