CO2 Winterization Equipment
Cannabis Winterization Equipment

CO2 Winterization/Cannabis Winterization Equipment

CO2 Winterization is the process of removing compounds such as fats, lipids, waxes, and chlorophyll from CO2 extract/crude oil prior to the distillation process.

Plants contain many compounds, so they are also included in the CO2 extract. For example, vegetable waxes, fats, lipids, and chlorophyll, need to be removed from the CO2 crude extract prior to the distillation step. Failure to remove these reduces the purity of the target you are trying to capture and reduces the clarity of the CO2 essential oil, thereby compromising the value of the product.

In a nutshell, the winterization of oil involves dissolving a non-polar substance CO2 crude extract in a polar solvent (ethanol) at sub-zero temperatures. This action creates a mixture as ineffective against CO2 essential oils, which must be kept at sub-zero temperatures so that the compounds you want to remove can condense and be filtered out. Read More: CO2 Extraction Machine: 3 Types, 4 Tips For CO2 Extraction, 5 Notes To Choose The Right CO2 Extractors

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

Three Steps of CBD Winterization

Step 1: Dissolve the extract in ethanol

Dissolve the extract in 30 to 60°C of ethanol using a 10 mL:1g (ethanol: extract) ratio. Stirring the solution using a lab spatula or using a magnetic heater/stirrer with a stir bar will do the trick. Now the extract is suspended in ethanol. The waxes, lipids, and fats have now been dissolved in the solution. Solvent at warmer temperatures completely dissolves the sample. Cooling the solvent, the solubility is decreased, and the waxes are precipitated out. These fats have a lower solubility in cold ethanol compared to warm ethanol, which is why the next step is to freeze the solution.

Step 2: Make the solution as cold as possible

Using a chiller/freezer, get the solution as cold as possible, and maintain sub-zero temperatures. While in theory, it sounds easy, maintaining these sub-zero temperatures can be a problem. Waiting at least 24 hours should be enough time for the waxes to precipitate out of the solution. You will notice a layer of fats has formed on top of the ethanol solution. Not maintaining the correct sub-zero temperatures will cause the waxes, lipids, and fats to not separate, and the winterization of oil cannot efficiently be completed.
Note: If this step is not performed correctly, the cannabinoid purity will be lower and the distillate will be less transparent, hurting the value of your product. This makes them easy to filter out with a fine filter and a layer of ciliate or diatomaceous earth (DE).

Step 3: Filter out as much precipitate as possible

The vacuum filtration system is the final step using a vacuum pump, Buchner funnel, and filter paper, it will help pull the miscella through the filter. The filtration must also occur quickly since it must stay cool to ensure the lipids and waxes don’t dissolve back into the solution.

5 Tips for Filtering

• The highest surface area filter paper will allow you to filter out as much precipitate as possible.
• Keeping the funnel and filter papers as cold as the solution will keep the fats from going back into the solution after coming into contact with the warmer surfaces.
• Using separate filters may help with the filtration, as higher micron-sized filters will take out most of the fats but using smaller micron filters will filter the smallest particles of fats.
• Once the filtration apparatus is set up, use cold pure ethanol to pre-wet the filter paper and apply a vacuum. Then slowly pour the solution onto the filter paper.
• A build-up of fats will block the ability of the filter paper to continue to pull the solution through.