Cannabis concentrates are products derived from the cannabis plant, created to isolate and amass desirable compounds like cannabinoids and terpenes into a highly potent form. Extraction methods fall primarily into two categories: those that employ a chemical solvent and those that rely on purely physical or mechanical separation. This difference influences the final product’s flavor, purity, and manufacturing process. Understanding the distinction between solvent-based and solventless methods is necessary to properly classify products and address the common query regarding live resin.
How Live Resin is Extracted
Live resin is a type of cannabis concentrate known for its robust flavor and aroma. This quality is achieved by using fresh or “fresh frozen” plant material immediately after harvest. The material is frozen to sub-zero temperatures, sometimes as low as -40°F, to preserve volatile monoterpenes typically lost during traditional drying and curing. This preservation of the natural terpene profile gives live resin its distinctive quality.
The production of live resin is accomplished through a closed-loop hydrocarbon extraction system, explicitly requiring the use of chemical solvents. The frozen plant material is washed with light hydrocarbon solvents, such as butane, propane, or a blend of both. These solvents are chilled to extremely low temperatures to selectively dissolve the trichomes, which contain the desired cannabinoids and terpenes, while leaving behind undesirable compounds like waxes and lipids.
The resulting liquid solution is then collected for post-processing. Because this method relies on chemical solvents to separate the plant compounds, live resin is classified as a solvent-based concentrate. The use of hydrocarbons allows for the efficient and selective extraction of compounds from the fresh-frozen biomass.
What Defines a Solventless Concentrate
A solventless concentrate is defined by the complete absence of chemical solvents, such as butane, propane, ethanol, or carbon dioxide, during the extraction process. These concentrates rely solely on physical or mechanical separation techniques to isolate the resinous trichomes from the cannabis plant material. This method ensures the product is free from residual chemical compounds.
One common solventless method is the creation of ice water hash, also known as bubble hash, which uses ice and water to separate the trichome heads from the plant matter. The cold water makes the trichomes brittle, allowing them to break off easily. The mixture is then filtered through fine-mesh screens, or bubble bags, to collect the resin glands, physically isolating the desired compounds.
Another popular solventless product is rosin, made by applying precise amounts of heat and pressure to the starting material, which can be cannabis flower, kief, or bubble hash. The heat and pressure cause the resin contained within the trichomes to melt and squeeze out onto collection paper. This mechanical process directly extracts the oil.
Ensuring Safety and Purity in Solvent Based Products
Since live resin is produced using volatile chemical solvents, the manufacturing process must include a rigorous post-extraction step to ensure consumer safety. This step, known as “purging,” removes trace amounts of residual solvents from the final concentrate. Purging is typically performed by placing the crude extract into a vacuum oven and applying low heat.
The reduced pressure and gentle heat cause the residual solvents, such as butane and propane, to evaporate out of the concentrate. Even with careful purging, trace amounts of solvents can sometimes remain, which is why regulatory bodies mandate third-party testing. This required process, called Residual Solvent Testing (RST), uses advanced analytical techniques like Headspace Gas Chromatography to measure the parts-per-million of any remaining volatile organic compounds. The final product must meet strict, state-mandated safety thresholds to ensure it is safe for consumer use.