🇺🇸 Retired veteran, father, rock-climbing expert & rosin connoisseur.
Solventless cannabis concentrates are made by isolating, accumulating, and condensing cannabis trichomes into a pure and potent form, all without the use of chemical solvents like butane, CO2, or ethanol which are commonly used in other processing methods. Solventless techniques allow extractors to capture the most therapeutic compounds made in cannabis, namely the THC and terpene-rich resin that’s located within a flowering plant’s trichomes.
While high quality extracts can also be created with the help of solvents, for example in a closed loop distillation system, a total lack of contact with any potentially harmful chemicals is an undeniable benefit of solventless products.
It might be a different story if solvent-based methods produced a far-superior product in terms of taste, potency, and effect. But that’s not the case. Solventless methods are capable of producing a quality of product that’s second to none. But it also requires a skilled extractor that can walk the line between science and art.
Solventless processing methods won’t hide subpar starting material. Even the best extractors are bound by the overall quality of the flowers. The quality of solventless products will not exceed the quality of resin that the cannabis flowers produce.
Perceived quality for solventless concentrates is unmatched in the market, because of the top-tier starting material that’s required to create them. It’s impossible to produce premium solventless concentrates without premium cannabis flowers to start with.
And it all come down to the trichomes.
A variety of techniques can be used to isolate and process these resinous globes of goodness. Different ways of working with these resin glands, also called heads, produces different forms of solventless concentrates. For example, one method of solventless processing involves ice and water, while another method involves heat and pressure.
The three main forms of solventless cannabis concentrates include bubble hash, rosin, and dry sift.
Let’s look at the various forms of cannabis concentrates and the methods used to make them.
Bubble hash is simply trichome heads in loose form. Bubble hash is made using a process called Ice Water Extraction, in which ice water and cannabis is mixed together and seived through a series of mesh filters called Bubble Wash Bags. You could think of this method as “washing” the resin off of the cannabis plant, using only ice cold water. Hence the term “washing hash” which you’ll often hear in reference to making bubble hash.
Bubble wash bags are made with filter material of varying pore sizes, measured in microns. The bags with mesh filers that most closely resemble the size of trichome heads will yield the best quality bubble hash.
Bubble hash in it’s unprocessed form resembles thousands of grains of sand. Every “grain” is actually a trichome head, which has remained in tact and packed with resin. These heads range in color from light blonde or sometimes even translucent, to a rich golden amber.
Cold temperatures are required throughout the entire washing process, which allows extractors to properly isolate, collect, and handle the resin. Significant attention goes into keeping equipment and environment near-freezing when possible. The task may sound daunting, but it’s actually a straightforward process that most people can do right at home.
Even drying out the wet bubble hash, one of the most critical aspects of the entire process, can be achieved with minimal equipment. The key is environment.
Once the the loose resin is collected and dried, it’s ready to use. Hash is good to mix with flowers for smoking in a joint, or sprinkled like a topping. You can use bubble hash to infuse butter or oil for edibles. There’s a more ancient approach as well, which is making a Temple Ball.
A temple ball is a preparation of bubble hash that prepares the loose resin for long-term aging. Aging resin is like aginig wine or cheese - there is a chemical transformation that takes place, which will actually enhance the quality of the product over time.
To make a temple ball, hash makers press loose resin together, folding and pressing and folding and pressing. A wine bottle filled with hot water is used to aid in pressing the heads together into one solid mass. Similar to the action for rolling bread dough with a rolling pin, the hot bottle is passed back and forth across the hash, gently pressing the trichomes together and causing their protective outer membrane to burst. This releases the resin inside, which allows the whole mass to congeal.
The pressed heads are then rolled into a ball using circular motions between the palms of the hands. The ball should be nice and smooth, with this outer layer acting as a shell to protect the oily resin inside. As the outside of the temple ball oxidizes, it forms the perfect environment in which the resin can age inside.
Learn more in What Is a Bubble Hash Temple Ball?
Finally, loose resin also makes a great starting material for pressing rosin. Rosin is another form of solventless cannabis concentrate, which we’ll look at next.
Read more about bubble hash and ice water extraction in these articles from our archive:
Rosin is another form of solventless concentrate, and it's probably the most popular.
Rosin is an oily substance that’s made through squishing cannabis trichomes between heated pressing plates, bursting the the heads and liquefying the resin inside. Starting material for rosin can be dried and cured cannabis flowers, loose resin (bubble hash), or dry sift. The material is packed into rosin bags, which as as filters to clean out unwanted contaminants. As pressure is exerted onto the rosin bag and starting material during extraction, the liquefied resin is forced through the filter bag where it drips onto a sheet of parchment paper for collection. From resin to rosin.
Some rosin looks creamy and buttery, but it can appear runny and sappy too. Some rosin even looks like diamonds. These different appearances manifest though various methods of curing. Once rosin is collected it’s ready to consume, fresh-off-the-press. However, curing rosin can bring about intriguing transformations.
There are many ways to describe different batches of rosin, including the specific cannabis cultivar it comes from, the method of curing, and the type of starting material used for extraction.
The two main types of rosin include hash rosin and flower rosin.
Hash rosin is made from pressing bubble hash into rosin. The cannabis used to make the bubble hash can either be dried and cured flowers, or fresh frozen flowers. Fresh frozen material is frozen immediately after harvest to preserve terpene content and minimize oxidation. This keeps the flavor in tact and the color nice and light, especially when coupled with a freeze dryer for drying the hash. Fresh frozen hash rosin is seen as one of the most premium products on the market.
Learn more about hash rosin in How To Press Bubble Hash Rosin Starter Guide.
Flower rosin is made from pressing dried and cured cannabis flowers. Flower rosin is the most straightforward rosin to make, and it’s a great way to get into the world of pressing rosin. You can even do it with just a hair straightener, some parchment paper, and a few rosin filter bags.
Make sure the flower you’re using is covered in trichomes and contains the right amount of moisture. Aim for 60-65% relative humidity in the flowers before you press them, which will maximize yield.
Learn more about flower rosin in How To Press Flower Rosin Starter Guide.
Curing rosin is a simple process for both flower and hash rosin, yet it can lead to complete transformation in the consistency of both flower rosin and hash rosin. All you need is a glass jar with an airtight lid, a heating mat (if you want to warm cure), and a dab tool. Curing gives the fresh rosin a better shelf life and often brings out an enhanced, more complex flavor profile.
Read more about rosin in our archive:
Dry sift is the third type of solventless cannabis concentrate.
Dry sift is similar to bubble hash in that it’s composed of trichome heads in loose form. Dry sift often looks a lot like bubble hash, with a blond or amber, sandy-like consistency. But unlike bubble hash, the process to make dry sift doesn’t involve ice water. The similarity in process lies within the basic sieving method. While ice water extraction relies on bubble wash bags for sieving, dry sifting utilizes a series of dry sifting screens.
These screens are made of nylon mesh just like bubble wash bags, but the nylon is stretched taut within a rectangular metal or wooden frame. Dry and cured canabis flowers and trichome-rich trim leaves are whisked back and forth across the dry sifting screens, which knocks the trichome heads loose. These heads fall through each screen, as the pore sizes get smaller and smaller.
Dry sift also makes a good starting material for pressing rosin.
Read more in our The Ultimate Guide To Dry Sift.
Solventless cannabis concentrates capture the essence of the cannabis plant from which they're made. Solventless extractors aren't making magic, they're just isolating and concentrating the resin that a cannabis plant produces. And any great solventless concentrate started with a skilled farmer who raised the plants with care.
Solventless extraction is a blend between art and science. It doesn't require any super specialized or ultra expensive equipment. Some of the best extractors work right from home, with equipment that's readily available in the US. With the various forms of solventless concentrates that exist today, there are a lot of different ways to take your extraction efforts.
Solventless concentrates are ideal for safely, quality, and economics of production. Whether for business or for hobby, crafting solventless products is one of the most exciting and rewarding ways to work with the cannabis plant.
Thoughts? Let us know by joining our secret Facebook group. Hang out with a community of like-minded solventless heads like yourself. Ask our head extractor questions, share your latest press and learn from hobbyists and experts in the industry.
FREQUENTLY ASKED QUESTIONS
What are solventless cannabis concentrates?
Solventless cannabis concentrates are made by isolating, accumulating, and condensing cannabis trichomes into a pure and potent form, all without the use of chemical solvents like butane, CO2, or ethanol which are commonly used in other processing methods.
What are the main forms of solventless cannabis concentrates?
The main forms of solventless cannabis concentrates are bubble hash, rosin, and dry sift.
What is the best form of solventless cannabis concentrates?
Hash rosin made from fresh frozen material is seen by many people as the pinnacle of solventless extraction. That said, all forms of solventless products are capable of being standouts in purity and potency.
What is the easiest type of solventless cannabis concentrate to make?
Flower rosin is probably the easiest to make. All you need is high quality dried cannabis flower, a hair straightener, some rosin filter bags, and a few sheets of parchment paper.
How do you press rosin?
Pressing rosin involves squishing a cannabis starting material (dried and cured flowers, bubble hash, or dry sift) in between heated rosin plates at high pressure. Heat and pressure causes the trichome heads to burst, and the oil inside to escape. This oil is collected as rosin.