Winterization Process of CBD crude extract
Winterization is performed after the initial extraction process. Most primary extraction methods to obtain crude will require you to perform this step, as butane, propane, and CO2 are nonpolar and will dissolve excessive plant material. The crude extract is dissolved in a solvent, commonly ethanol, and the solution is placed in a freezer. The colder the temperature, the faster fats, waxes, lipids, and other inactive compounds will precipitate from the solution. The precipitate will flocculate together and form a large, fatty-looking mass suspended within the solution.
The solution must then be passed through a filter to remove the solidified fats and waxes. The freezing and filtration steps are often repeated multiple times to fully remove all inactive compounds. After the undesired components are fully removed, the crude extract must be separated from the solvent by evaporation.
Notes: Ethanol, which is polar, if kept at extremely cold temperatures, will pick up far fewer fats, lipids, and waxes in the primary extraction, thus making it not as necessary to do this process.
Read More: Winterization of oil Wikipedia