The Difference Between Solvent vs. Solventless vs. Solvent-free Extractions
Cannabis enthusiast and student of the art of solventless extraction
Cannabis extracts are potent concentrations of the compounds that cannabis is most known for. These extracts take on a variety of forms like wax, shatter, bubble, rosin, crumble, and sugar among others. Extractors have several techniques to choose from, and the extraction method that they use determines the nature of the final product.
Solvent, solventless, and solvent-free are terms to describe broad categories of cannabis concentrates. Each of these types of extracts results from different extraction techniques. In this article, we’ll look at each one of these and point out their differences. We’ll also draw some conclusions and suggest which one is best.
But first, let’s quickly review the basics of cannabis concentrates and what specifically extractors are after.
The Basics of Cannabis Concentrates
Cannabinoids and terpenes are the main targets of cannabis extractors. They’re the compounds that deliver the most therapeutic value to consumers. Cannabis produces these compounds in high concentrations within the trichomes, which are tiny appendages made of a stalk and bulbous tops. These tops, or heads, are really what cannabis extractions are all about.
The goal of extraction artists is to capture the magic inside these heads, while leaving everything else behind. This “everything else” includes all the rest of the plant material. The best cannabis extracts contain only the oily resin that’s inside the trichome heads.
So how do extractors accomplish this? They can use solvents, or stick with methods that don’t use solvents. Solvents like butane or carbon dioxide break apart the trichome heads and chemically separate the desired compounds from everything else. These solvents are not good to consume, so a purging process afterwards is necessary.
Fortunately, there are methods that don’t rely on solvents.
Solvent, solventless, and solvent-free extracts are the main categories of cannabis concentrates. Let’s dig into each one and see what we find.
Solvent Extracts
Solvents allow for a very precise and targeted extraction process, and this is well-suited for larger commercial operations that process tons of cannabis material. These solvents essentially dissolve the trichomes, expose the oily resin inside, and then separate the desirable compounds at the molecular level.
Common solvents used in cannabis extraction include butane, propane, alcohol, carbon dioxide, among others. These solvents are dangerous to work with, and using them in homemade labs can lead to some catastrophic consequences. Building out a proper lab, including the equipment necessary to safely work with solvents, is prohibitively expensive for all but the most well-funded operations.
These solvents are also not safe for human consumption. Therefore, these concentrates require a purging process to remove the solvents from the final product. They're not completely removed, but they're brought down to manageable levels for these types of extracts.
Common concentrates made with solvent-based extraction techniques include various forms of BHO (butane hash oil) including wax and crumble, and alcohol-based tinctures.
Solventless Extracts
Solventless extractors produce concentrates without the use of chemical solvents. The techniques to separate, isolate, and collect trichome heads are mechanical rather than chemical. Techniques like pressing rosin and ice water extraction, which is a method of making bubble hash, are the most common types of solventless extraction.
Hash makers use water in ice water extraction, and while water is technically a solvent, it doesn’t present any risk to consumers. Furthermore, all the water is removed from the final product through the drying process.
Ice water extraction involves mixing cold water and cannabis together to allow the trichome heads to fall away from their stalks. Then extractors filter this cannabis and ice water mixture through a series of sieves called bubble wash bags. The bags catch trichomes while other plant particles can slip through, making it easy for extractors to scoop out the heads with a spoon. The loose resin gets dried and then it’s ready for aging or pressing into hash rosin.
Pressing rosin involves heat and pressure to break open the trichome heads and force out the oil that’s held inside. This oil runs through a filter, known as a rosin bag, and then comes out as rosin. You can learn all about pressing rosin in our article What Is Pressing RosinWhat Is Pressing Rosin?.
Dry sifting is another method of solventless extraction. Sifting uses a series of filter screens and follows the same basic principles as ice water extraction, but without the ice water. The resulting extract is called dry sift, which is often pressed into rosin.
Rosin, bubble hash (also called loose resin), and dry sift are the main forms of solventless extracts.
Solvent-free Extracts
Solvent-free extracts are like the close cousins of solvent extracts. Solvent-free extracts are created using solvents, but then they undergo another process to remove those solvents. The process that extractors use to remove the solvents post-production is called distillation.
Distillation brings the presence of solvents down to zero. Solvent-free extracts, when made properly, don’t contain any measurable traces of solvents. Terpenes are often added back into the extract after distillation.
Solvent-free extracts still have the downside of requiring solvents in their production. The equipment and safety measures needed for extraction means that they are suited for larger commercial operations, and not advisable to make at home.
The most common form of solvent-free extract is CO2 distillate, which is often used in vape cartridges.
Which Type of Extract Is Best?
In our opinion, it’s not even a competition. Solventless is the only way to go. While we definitely acknowledge the value that solvent and solvent-free extracts bring to the broader cannabis market, they aren’t the best options out there.
Solventless extracts are pure and potent, versatile in their ability to take on a variety of forms and consistencies, and safe and simplistic to produce.
Read more in our article Top 3 Reasons Why Solventless Is Better.
Conclusion
Solvent, solventless, and solvent-free are the broad categories of cannabis extracts. Solvent extracts use chemical solvents to isolate cannabis compounds at the molecular level, while solventless extracts rely only on mechanical processes only. Extractors make solvent-free extracts using solvents, but then use a process called distillation to remove the solvents afterwards.
We recommend sticking only with solventless extracts. They’re top-quality, safe, and easy to make at home.
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 solvent extracts?
Extractors use chemical solvents such as butane or alcohol to make solvent extracts like BHO.
What are solventless extracts?
Extractors rely on mechanical processes only, like rosin plates or ice water, to make solventless extracts. No chemicals are used in production. Solventless extracts include rosin and bubble hash.
What are solvent-free extracts?
Solvent-free extracts are cannabis concentrates made with solvents, then put through the process of distillation to remove all traces of the solvent after production.
What is the best type of cannabis extract?
We recommend solventless extracts over solvent or solvent-free extracts.
What are the main forms of solventless extracts?
Rosin, bubble hash, and dry sift are the main forms of solventless extracts.
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