Solventless vs. Solvent-Free: The Difference Between Rosin & Resin
Updated: Dec 8, 2021
Dabs, or cannabis concentrates, are the product of extracting more of the stuff we want (ie. cannabinoids and terpenes) and less of the stuff we don’t (ie. plant matter, fats, lipids). The only exception to this rule would be Rick Simpson Oil prepared in the traditional sense.
At Big Island Grown we use several methods of extracting concentrates including closed-loop hydrocarbon extraction, solventless ice-water extraction, distillation, and ethanol extraction to provide our resins, rosins, distillate, and other cannabis concentrates.
In this article, we will look a little closer at these extraction methods and the products they produce.
Solventless vs Solvent-Free
While they can be called different things, there are essentially two main categories of cannabis concentrates; we call them Solventess & Solvent-Free. This is the difference between Rosin & Resin. But technically, the term “Solventless” is a bit misleading. While water is not a volatile substance, it actually is a solvent just not for cannabis. A solvent can be defined as any substance that is able to dissolve other substances. Water is a common solvent in many applications. However, with cannabis, we use ice water to extract cannabinoids and terpenes because they are, in fact, insoluble. In this process, the ice-water freezes the trichomes and with agitation, they are broken off of the plant material to be later pushed through a series of screen filters to isolate the cannabinoids and terps. Despite the technicality that water (AKA the Universal Solvent) is used for this method, the industry has adopted the term “Solventless” to identify any concentrates extracted using this technique. Extracts that are considered Solventless include bubble hash, rosin, and dry-sift hash.
Solventless methods can produce beautiful, full-spectrum concentrates without the need for expensive equipment. While these extracts do not use any solvents it is more likely to leave behind plant material, lipids and fats and tend to be less potent than hydrocarbon extraction.
To be fair, the term “Solvent-Free” is also slightly misleading. While the final concentrate can technically be solvent-free, it doesn’t mean it was extracted without the support of a solvent. When we say solvent-free, we are referring to clean hydrocarbon extraction and distillation that has been purged of any residuals.
Utilizing hydrocarbon extraction equipment allows us to create some of the purest and most potent artisanal concentrates possible. This system, however, requires specialized equipment, skilled operators, and high-quality starting material.
Currently, B.I.G. is the only legally licensed hydrocarbon extraction operation in the state of Hawaii that is licensed to extract with all hydrocarbons including propane and butane. It is worth noting this because there is a big difference between lab-extracted hydrocarbon concentrates and backyard hydrocarbon extractions. The environment of the lab, the quality of the hydrocarbon, the purging process and the testing standards that we go through are all key factors to ensure a final product that we are proud to put our name on and that you can trust.
What are Hydrocarbons?
Hydrocarbons are organic chemical compounds consisting of hydrogen and carbon. Butane is a hydrocarbon frequently used for cannabis extraction—its low boiling point of 30.2°F (-1°C) allows us to avoid exposing temperature-sensitive terpenes to heat.
Fun fact: A lot of terpenes are actually hydrocarbons.
Are Hydrocarbons Safe?
In short, yes. Many natural food flavorings, soybean oil, vegetable oil, and other food products consumed on a daily basis are products of hydrocarbon extractions. The truth is, you’re going to breathe more hydrocarbon sitting in traffic than you ever would consuming hydrocarbon extracts. It is said that someone who smells a whiff of butane from a Bic lighter has already inhaled way more than they will get in an entire day of dabbing dispensary quality concentrates!
The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for n-butane is 800 ppm (1,900 mg/m) as an 8-hr time-weighted average. Put differently, OSHA has said that direct exposure to butane is safe at 800ppm for 8 hours/day. A study cited by the US Departm