Commonly known as a rotavap, this machine can purify cannabis concentrates. Using rotation and gentle heat, a rotary evaporator can remove contaminants or further concentrate desired cannabinoids. Rotavaps are frequently used to improve the winterization process.
“If you want to make a truly high-quality distillate, you need to invest in a good rotavap.”
What is a rotary evaporator?
A rotary evaporator, also called a rotavap, is a machine that separates residual solvents from cannabis concentrates. Through rotation—which acts as a type of filtration—and gentle warming, a rotavap can either remove unwanted contaminants, or isolate a desired cannabinoid.
There are seven main components to a rotavap:
- An evaporation flask or vial, which holds the sample material
- A motor that rotates the flask or vial
- A vacuum-sealed vapor pathway, which draws vapor off the sample
- A vacuum system, which significantly reduces pressure in the evaporator
- A heated fluid bath (usually water), which gently warms the sample
- A condenser or “cold finger,” which can be filled with dry ice or other coolants to make vapor recondense
- Another flask to collect condensed vapor after distillation
In the cannabis industry, rotavaps are commonly used during the winterization process, to purge waxes and lipids from a cannabis extract at a low temperature. Beyond winterization, rotavaps have other applications: A rotavap can turn raw cannabis flower into high-grade THCA isolate diamonds, and if calibrated differently, a rotavap can be used to make oils and tinctures.