Solventless is a term used to describe cannabis extractions and concentrates that are made without the use of chemical solvents.
Solvent-based vs. solventless: how cannabis concentrates are made
If you're a fan of cannabis concentrates, you probably already know how many different product options there are. And if you're new to concentrates, it might seem daunting to weed your way through products with names like wax, shatter, budder, bubble hash, and rosin.
Regardless of what concentrate we are talking about, they can all be organized into two broad categories based on how their active ingredients (like cannabinoids and terpenes) were extracted from the cannabis or hemp plants: with the use of solvents or without.
For solvent-based extractions, a chemical solvent like butane, carbon dioxide (CO2), or ethanol is used to separate cannabinoids, terpenes, flavonoids, and other compounds from the plant material. You can find solvent-based extractions in products like wax, shatter, and budder. Solventless extractions, on the other hand, rely on mechanical processes to remove the resin-filled trichomes from the plant.
In recent years, solventless concentrates have gained popularity with medical patients and other folks who want to avoid the possibility of residual solvents. However, when properly and thoroughly purged, most solvent-based extractions contain only trace amounts of residuals, and most states have strict regulations around residual solvent content.
Solventless versus non-solvent versus solvent-free
Where things can get a little more confusing is when we look at different terms you might see on concentrate products, including labels like solventless, non-solvent, and solvent-free. It's understandable to assume that these terms mean the same thing, but there is one important distinction.
Generally speaking, solventless and non-solvent labels are used for products containing an extract made without solvents, whereas solvent-free is typically used for extracts made using solvents that were thoroughly purged or purified to remove any trace of residual solvent.
To summarize, solventless and non-solvent products were made without the use of solvents, whereas solvent-free products were made using solvents that were purged from the final product.
Rosin, ice hash, and other common solventless extracts
Hashish, or hash, is the original solventless concentrate. The making of hash is an ancient tradition, developed and popularized by countries like Morocco, Lebanon, Pakistan, and Afghanistan centuries ago.
While these ancient techniques have been improved upon and modernized over time, traditional methods are still widely used to produce high-quality concentrates enjoyed by cannabis connoisseurs all over the world.
More recently, rosin is a solventless option that has gained popularity with dispensaries and at-home concentrate makers alike.
Solventless concentrates you can make at home
Here are a few solventless concentrates you are likely to come across or might want to try making yourself at home:
Dry sift hash
Dry sift hash is made by agitating dried and cured cannabis flower over a series of fine screens that filter out the more crude plant material while allowing the tiny resin-filled trichomes to pass through. The resulting fine powdery residue, which is also referred to as kief, gets collected and pressed into blocks of hash. This is also a fairly easy way of making hash at home, requiring little equipment or investment to get set up. Many cannabis grinders have a kief collector at the bottom so it's easy to gather kief for hash-making efforts.
Also known as ice water hash, bubble hash, and wet sift, ice hash is another solventless concentrate made by agitating plant material to shake off the trichomes and filter them from plant material. Instead of using mechanical separation, ice water is used to freeze the trichomes, which sink in the ice water and are then filtered out. Because this concentrate bubbles when smoked, it's often called bubble hash, and DIY hash makers can use “bubble bags” to make it at home.
Rosin is a solventless concentrate made by exposing cannabis flower, kief, hash, or frozen fresh buds to heat and pressure, which encourages the cannabinoid and terpene-rich resin inside trichomes to be released. Rosin extracts are often categorized by their texture and appearance, like many solvent-based concentrates: shatter, pull-and-snap, budder, sap, and sauce. Rosin made from frozen fresh (not dried and cured) cannabis is called live rosin.
While the process for making rosin has been around for nearly two decades, it rose in popularity in and around 2015 when cannabis connoisseur Phil “Soilgrown” Salazar started sharing techniques on social media. Today, folks can make rosin at home using little more than some basic precautions along with a hair straightener, starting material, and parchment paper.
Solventless or non-solvent are two terms used to identify cannabis concentrates that were made without the use of chemical solvents. Solvent-free products have been purged of solvents used in manufacturing. While solvent-based extraction techniques have greatly increased the number and variety of concentrates available to cannabis consumers, solventless concentrates are often sought out by those who want to avoid chemical solvents altogether or want to attempt making relatively easy and safe concentrates for themselves at home.