Cannabis & Hemp Winterization

Winterization is an important step in the purification of oils. Cannabis and hemp winterization that allows for the removal of inactive compounds like fats, waxes, and lipids.

The Importance of Winterization

Winterization is a vital step in the purification of oils, including cannabis extracts. Winterization allows for the removal of inactive compounds like fats, waxes, and lipids. This process can be performed in a few different ways but what each has in common is the use of cold temperatures to facilitate precipitation of the undesired compounds. The resulting solids are then removed via filtration.

Winterization is most commonly performed as a post-processing step, but there are other techniques that can also be used to keep cannabis extracts free from undesired compounds. Below, we will expand upon winterization in cannabis processing and its effects on end product creation.

Why Winterization?

Winterization is a key step in the chain of cannabis processing. It creates clean crude extracts that are free of fats, waxes, lipids, and other inactive compounds. Those compounds contribute a poor flavor and aroma to end products and can also cause potential health risks from ingesting them. Winterized extracts are more sought after by the market, and while they take a few extra steps and pieces of equipment, they will provide you with higher-quality products to bring to market.

Winterization In Post Processing

Winterization is performed after the initial extraction process. 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. For small-scale processing, filtration is easily accomplished with a vacuum-assisted Buchner Funnel. At larger pilot-and-industrial scales, Filter Presses, Lenticular Filters, Bag Filters, or other methods may be used.

Filter Press

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. This may be performed in rotary evaporators, falling film evaporators, recovery membranes, and more. This process creates a clean and appealing crude extract that can be turned into many marketable end products such as high-quality distillate, isolate, edibles, and topicals.

Inline Winterization & Alternatives

While not technically winterization, there are other methods for keeping extracts clean from waxes, fats, and lipids. These may be performed through control of variables, inline with extraction, through specialized membranes, or by introducing additives to induce precipitation.

In closed-loop hydrocarbon extraction systems, solvent is often injected into the system at an ultra-low temperature. As the solvent washes over the cannabis plant material, it does not extract the unwanted inactive compounds due to the effect of cold temperatures on solubility. This reduces post-processing steps and allows the extraction process to create a desirable end product without additional equipment for winterization.

Some closed-loop extraction systems also have a secondary column that performs inline winterization. The secondary column holds only the crude extract solution, which is then chilled to an ultra-low temperature. This is followed by a stack of filters that remove any precipitated fats and waxes. While this is inline winterization, it is often referred to as “dewaxing”.

The same temperature dependence on the solubility of a solvent also applies to ethanol extraction. When the ethanol solvent is properly chilled prior to the extraction, it will not dissolve fats, waxes, and lipids from the plant material due to the extremely cold temperature. Similar to the secondary column in the closed-loop example above, winterization may also be performed inline immediately following ethanol extraction by channeling the crude extract solution into a secondary vessel that chills to an ultra-low temperature.

After chilling, the solution is forced through an inline filtration system to remove the precipitated compounds. This reduces possible contamination by never exposing the solution to the atmosphere.

Membrane Filtration

Membrane filtration is another method of dewaxing and an alternative to winterization. This method removes fats, waxes, and lipids from the solution but does not require ultra-low temperatures. In fact, this method can be done at room temperature in most cases. Membrane filtration is achieved by permeation of the solution through the membrane and is often much faster than standard filtration styles due to the shape of the membrane and backpressure of the solution.

Why Choose?

Let us create a tailored solution to fit your processing needs. When it comes to winterization, we have the expertise and equipment selection you need to consistently produce cannabis oil at any scale, with any budget, and for any operational capacity.