Welcome to the new frontier of cannabis extracts, where many people are abandoning the tradition of burning the raw flower for dabbing refined medicine. Just look at any major cannabis event like the High Times Cup or the Emerald Cup where the booths that offer dabs always have the largest crowds. Cannabis extracts offers its users a more compact medicine that is less pungent, more flavourful, and has potency that is orders of magnitude greater than dry flower. In raw cannabis, the beneficial chemicals are only trapped in the plant's oils and resins that are produced by trichomes, while the bulk of the flower and plant do not contribute to any effect. There are a variety of ways to isolate and refine the medicinal oils from the unwanted material and extracts are categorized based on the method used. Different techniques will cause variation in the yield, cannabinoid profile, terpenoid content, and material consistency. Although a survey of concentrates would be fun, it is outside the scope of this post and you can read more about the different techniques here Of these techniques, Rosin tek is arguably the most accessible because it doesn't require dangerous solvents and uses simple skills that anyone can master.
Rosin tek is the application of intense pressure and the right amount of heat upon the plant material until it exudes out all the beneficial oils and waxes. Raw plant material is placed within a folded sheet of parchment paper and then pressed between heated plates. The heat from the plates melts the trichomes and liquifies the oils. The heat also causes any water within the plant to vaporize and turn into steam. As the force between the plates increase and water turns into steam, the intense pressure causes the oil to flow out of the plant and reconstitute onto the paper. Once the oil stop flowing, the plates are released and the flattened plant "chip" is cleared away leaving just the extracted oil on the paper. The extract then is gathered and collected off this paper. No other post-processing steps like purging are required and you can immediately dab or consume this extract.
The name "rosin" comes from the timber industry as a term for solid blocks of resin that are produced from fallen pine trees. However, in the cannabis industry the term rosin is used to denote extracts isolated with only the application of heat and pressure. It is unclear who or when rosin tek was first developed, but during 2015 @Soilgrown on Instagram popularized the technique by posting videos using a hair straightener and parchment paper to make rosin. Soon others replicated @Soilgrown and it became evident that yields and quality were on par or superior to other methods. Therefore the hype behind rosin is well deserved. If you get into pressing your own nugs into rosin, you can reliably expect 10%-20% of the starting weight to come out as the yield.
To anyone thinking about making their own cannabis extracts without a background in chemistry, I urge you to consider rosin tek first. Rosin tek is the most forgiving especially when you consider that mistakes with other techniques can lead to destruction of property, fatalities, and contaminated end product. With rosin tek you are still at risk for burns, crushed fingers, and gross inefficiency when you make mistakes. But most of us would consider these risks to be more manageable and easier to recover from. In order to produce rosin there are 4 important factors that we need to bring together: obtaining good starting material, creating and applying intense force, heating to the right temperature, and spending the right length of time squishing.
1. The Starting Plant Material
The old adage of "garbage in, garbage out" very much applies to rosin tek: if you don't have enough trichomes or crystals in your starting material, then your yields will be dismal. The ideal starting material is highly saturated with trichomes, crystals, and resin throughout the bulk of the material. Rosin made from bubble hash and kief yields the strongest rosin with the greatest returns. Typically, the returns from bubble hash rosin are in the 50% to 60% of the starting weight and there is tighter consistency to what is being produced. For example, if you were process 7g of "Blue Dream" bubble hash and 7g of "Lamb's breath" bubble hash, you can expect the yields from both to be similar in weight and potency. Bubble hash is essentially pre-processed and since both starting materials had the same treatment, they end up having the same trichome saturation. On the other hand if you only have access to nugs, the variation between rosin is far more variable. I refrain from making yield predictions when I am doing nug runs because I am often surprised by the good or bad results. It is much harder to choose the right nugs for optimum rosin production as the strains vary widely in overall anatomy, saturation, and how they have been dried and cured. Generally, you want to choose bud that is saturated with trichomes and crystals, is sticky to the touch, and is trimmed perfectly. I tend to favor bud that has been dried and cured well because consistency of the end product is easier to handle. The more wet your nugs are, the more runny and watery your extract will be. This in turn makes it harder to collect the it from the parchment paper. Some people choose to use not fully dried or cured nugs to process into rosin because some desirable chemicals start to degrade as the pH changes during the cure. Sometimes these "wetter" rosins need to be post-processed to remove excess water. Additionally, it is possible to process trim and shake into rosin as long as it saturated with crystals. For starting materials composed of small particles like bubble hash or trim it is important to use a nylon micron bag or a hemp filter bag. This allows the oils to separate cleanly while keeping the inactive plant material together in one place.
2. Applying Intense Force
Rosin began humbly with a man using his body weight and strength to exert force upon a hair straightener. Although this works and how most rosin extractors get their start, upgrading to a mechanical press or clamp makes a world of difference. The immense force a press creates makes it easier to squeeze out all oils. Furthermore, unlike your arms a press does not tire out and can apply force can be constantly and evenly. Quick clamps, arbor presses, and hydraulic jack presses all fit the needs of rosin tek. In fact, most consumer rosin presses available for sale are a play on these designs. However, I would not recommend using a t-shirt press as they are not able to exert enough force. Should you choose to build your own press instead of buying one, how much space you can commit will determine the design. The smallest footprint would be with a Quick Grip setup which you can easily stow away in a drawer. Bench top presses like an arbor press outperform the clamp and stand alone presses that take up the most space perform the best. Most homebrew rosineers take apart a hair straightener to free the heated plates so that they can attach them to the ram and press bed. Using a 2-part epoxy like JB Weld or Blue Magic is a safe way to bond the plates to the press without worrying about heat wear. The route I followed was to purchase custom plates that had fittings and hardware that make it easy to attach to any ram. The advantage is that I can upgrade or downgrade my press based on size and performance needs.
3. The Right Temperature
The temperature of the plates needs to be hot enough to generate steam, but not hot enough to vaporize the beneficial chemicals. Rosin is pressed with temperatures from 170F to 300F, with most target temperatures around 200F. At temperatures above 315F you begin to degrade the psychoactive chemicals.6 Most consumer rosin presses have a temperature controller that allows you to adjust heat of the plates. The optimum temperature does vary between strain, but its best to start on the low end and increase the temperature until the oil flows readily. Hot temperatures tend to increase the yield but you must be careful as too much heat can cause chlorophyll to leach into the extract. Chlorophyll can turn the end product green and dark and ruin the flavour of the extract. If you intend on using plates from a hair straightener, then try to purchase one that has lower temperature settings. Hair straighteners that have temperatures above 300F can be used, but require much more finesse. For plates above 300F I would try using a second sheet of parchment paper over the first to act as insulation and try to gauge the heat with an IR temp gun. What metal the plates are made from effects how efficiently the heat will transfer and melt the trichomes. Some rosin presses and plate manufacturers use stainless steel as it can withstand intense pressure, but the heat conduction is not as good as 6061 aluminium or copper.7 Make sure your aluminium or cooper plates are thick enough or rated to withstand intense pressure or they will start bowing and failing.
4. Length of Time
When I first started pressing rosin, I would press the plant material and watch the extract seeping out of the plates onto the parchment. I would release the ram when I could not observe any more liquid flowing. Sometimes the starting material would stay under pressure for up to 3 minutes. The idea was to maximize the yield. However doing this caused my returns to be on the wet side and risked more THC converting to CBN instead of THCA. This THC-to-CBN conversion does impact the potency and the qualitative properties of the medicine. Thus time you press your material under comes down to personal preference. Now, I steadily ramp up the pressure to maximum force for a 1 minute or less until and then I release the ram. As a result my yields were practically the same, but the extract is not as runny and retains its potency. Also, the relationship between the time pressed and the temperature is inverse. This means the lower your temperature is, the longer you need to keep the material under the plates and vice versa.
The cannabis extracts community is moving at a blistering pace and Rosin tek is at the forefront of the scene. There are a few legitimate companies that are producing reliable presses and plates. Unfortunately there has been some high profile companies that have taken advantage of the rampant demand from this new market to scam people and produce shoddy machines. I am looking at you D-nail,rufiocraft and rosintechproducts.com. Do your due diligence and talk to other press owners if you plan to spend money on a consumer press or plates. Rosin tek's challenges still remain in how it can be scaled up efficiently, what all the parameters are for optimization, and how the process can be automated.
If you decide to become a rosineer, please share your experiences and field your questions with the community. We can only grow stronger by learning from each other.