Rosin is a sticky cannabis concentrate made by applying heat and pressure to plant material. As a solvent-free form of concentrate, it differs from its cousin resin, which is made by passing a chemical solvent through harvested cannabis. Cannabis can be pressed into rosin by a professional with an industrial press, or by a DIYer at home with a hair straightener. The technique can also be used to turn a lower-grade hash into a concentrate that can be dabbed.
More about rosin
Rosin production uses heat and pressure to force the cannabinoids and terpenes out of the trichome glands. Think of it like squeezing the juice from grapes or oil from olives, with the end result being similar to butane hash oil (BHO), but without the harmful chemicals.
Rosin production can be thought of as a simple alternative to closed-loop resin extraction, which is also used in making essential oils. Closed-loop extraction is time-consuming, requires technical training, a lot of expensive equipment — pumps, a tank, and a specially designed room to perform the extraction — and you won't have a usable concentrate until you purge all the residual solvents using a vacuum oven. Even then, there may still be minor amounts leftover in solvent-based extracts. (Warning: Do not try any processes involving chemicals at home. These should be left to professionals.
In contrast, the process of making rosin is considered safer than many other concentrates. The temperature and pressure used during extraction dictate the colors and consistency of the finished product, making rosin available as shatter, wax, badder/batter/budder, and taffy.
History of rosin
Although it may have accidentally been made long ago and there is much debate on its origin, rosin was first introduced to the cannabis community through ICMag in 2006 by forum member Compashon. It only gained notoriety in 2015 when Phil “Soilgrown” Salazar started making and snapping pictures of it while attempting to make use of some lower-quality hash.
While pressing the hash to flatten it out, Salazar noticed that resin started spewing out the side, leaving the original hash dry and unusable. Thinking he may have stumbled upon a new technique, he took a piece of hash, put it between parchment paper, and pressed it against a hot dab nail. Out came the oil, now known as rosin. He began using a hair straightener after experimenting with his wife's hair curler. She suggested he use the flat-iron tool, and after running out of hash, he began using buds. The oil came out the same way.
In the years since, rosin production has evolved to using screens and industrial presses to mass-produce more consistent products.
Consumer preference for rosin
Many people prefer the cleaner, more natural preparation of rosin because it doesn't involve the use of solvents, which have traditionally been butane, propane, or other petrochemicals. Finished rosin is solvent-free and can be consumed immediately without the need for careful purging.
Rosin production is also a simple mechanical process, making it more accessible to most people. Even a high-powered, expensive rosin press is less complex than a closed-loop extraction system used to keep solvent-based production safe. Since the chemicals used for that type of extraction are extremely volatile, the process is unsafe for non-professionals and illegal in most places. Rosin production is legal wherever cannabis is legal. It can be made safely at home with minimal investment, allowing home growers to make the most of their trim, typically a byproduct that's thrown away.
Rosin input material
A variety of input materials can be used to create rosin. The input material can affect how many plant contaminants are left in the rosin, which impacts the quality of rosin. Rosin produced using flower will be different from rosin produced using kief or ice hash, for example.
Rosin from buds typically has some contaminants in the form of plant material that make it through to the final product. They tend to be small pieces, but they can make a big difference in the flavor when dabbing rosin. The plant material will add a layer of burnt flavor to the overall experience. To avoid having too much plant material in your rosin, try using a rosin screen or mesh bag.
Dry sift kief or hash
Kief is the collected trichome glands from cannabis. Making rosin from kief adds an extra step to the preparation process but the rosin tends to be cleaner, since the trichomes are removed from the buds prior to exposing them to heat and pressure. This extra step ensures that no plant impurities make their way into the final product. Hash is kief pressed into a solid mass so the same applies to making rosin from hash or ice hash (hash made by agitating plants in an ice bath).
Live resin vs rosin
Although the terms are distinguished by a single letter, there's a major difference between live resin and live rosin. Both products start with fresh plant material or some that's been flash-frozen before being cured or dried. This preserves as many of the terpenes and cannabinoids as possible. The resin is then made with the usual chemical solvent extraction process, resulting in butane hash oil or something similar.
For live rosin, the plant material is first turned into bubble hash using an ice water bath and a system of mesh bags to separate the trichomes from the plant. The resulting hash can then be pressed into live rosin, a potent, solvent-free concentrate that retains more terpenes and cannabinoids than other concentrates while remaining free from residual solvents.
Making rosin at home
Making your own rosin at home is incredibly easy and fairly safe, unless you're prone to burning your fingers while holding a hot iron (it happens). You can use parchment paper and a hair straightener to produce rosin from flower, kief, or hash. It's as simple as placing your starting material between two pieces of parchment and clamping down with the straightener. If you prefer detailed, step-by-step instructions for making your own rosin, find them here.
Although you can keep rosin production at home simple with a hair straightener, some cannabis enthusiasts may want to go the extra mile by purchasing a rosin press. For commercial rosin production, manufacturers use heavy duty equipment designed to repeatedly press larger amounts of input material.
A lot of rosin equipment and techniques exist out there, including press kits, hydraulic presses, handheld presses, heater controllers, and more. Some come with extra-large plates, multiple plates, and up to 20 tons of pressure. High-end equipment isn't cheap but Walmart has a handheld model for $119.99 and a bigger tabletop model for $249.00.
Since it is a highly potent, concentrated form of cannabis, a little bit of rosin goes a long way. Once you've purchased or made it at home, there are a number of ways to consume rosin. You can smoke it in a glass bowl or joint with or without flower, vape it in a pen made for concentrates, or dab it using a dab rig, which is the most popular method.
Remember, this is a highly concentrated product full of cannabinoids and terpenes. Start with a small dose and work your way up. For medical patients, rosin is a fast-acting consumption method for quick relief.