A solvent is a substance, usually a liquid, that can dissolve other substances (called the solute), which forms a solution. In the cannabis industry, “solvent” concentrates refer to products made using chemicals such as butane, propane, ethanol, etc., which are added to a closed-loop system to extract cannabinoids and terpenes from cannabis plant material. Water is technically a solvent as well, and can be used to create bubble hash, even though this is usually referred to as a “solventless” concentrate.
“I prefer solvent concentrates like BHO because they’re more potent.”
What is a solvent?
A solvent is any substance that can be added to another substance—called the solute—to dissolve it, creating a solution. The exact quantity of a solvent needed to dissolve a solute changes depending on the temperature of the solvent. Solvents are often liquid, such as ethanol (alcohol), but can also be a gas (butane, propane, or hexane), or a supercritical fluid (CO2).
Solvents are separated into two categories, polar and non-polar solvents: polar solvents can be mixed with water, but non-polar solvents, such as hydrocarbons, do not mix well with water.
Water is considered the “universal solvent” because it dissolves more substances than any other liquid. Ethanol and glycerin are also commonly used as liquid solvents to make cannabis tinctures, and ethanol can also be used for winterization. Cannabis oil can also be produced using CO2 as a supercritical fluid as well.
Every solvent interacts with cannabis plant material differently—hydrocarbons tend to do a better job extracting terpenes and cannabinoids, and ethanol tends to extract pigments and lipids, which hashmakers usually purge out.
Solvent vs. solventless concentrates
In the cannabis industry, numerous hydrocarbons, such as butane, propane, hexane, etc., are used to extract cannabinoids and terpenes from plant material to create a concentrate—these are usually called “solvent” concentrates.
Water is also a solvent and can be used to create bubble hash—confusingly, this is usually referred to as a “solventless” concentrate. In the cannabis industry, “solvent” concentrates usually refer to anything made with a hydrocarbon chemical.
It is important to always buy concentrates from a legal, licensed dispensary, as they require products to have an acceptable amount of residual solvents.