Cold Pressed Extraction is the process of using mechanical force to extract essential oils from plant materials. As the name suggests, this is a “cold process” requiring little to no heat. Consequently, it’s a method that preserves heat-labile compounds such as low-molecular weight terpenes.
For this reason and for the fact that it doesn’t involve any solvent, this method is gaining popularity in the cannabis world.
How is cold press extraction performed?
Cold pressing involves using mechanical force for extraction. Traditionally, this was carried out by hand. That meant using specialized sponges to “squeeze out” essential oils from the plant material. Things have changed and now there are specialized devices for cold pressing.
To make an example, when it comes to citruses the whole fruit is placed in the extraction device and the process begins with abrasion and laceration to break down the citrus peel matter. Hence, cold press extraction has earned itself the moniker “scarification.” It is then followed by centrifuging to separate the compounds by weight.
Because there are no chemicals involved, cold-pressed extracts have better overall quality. While the output may be lower as compared to other methods, the purity of the extract is usually higher. You will find that cold-pressed oils have a “healthy” tag ascribed to them and thus have a higher price tag, this is because of the higher purity levels. Cold pressing needs to be performed rapidly to prevent exposing the extract to water or air inducing hydrolysis or oxidation respectively.
Because cold press extraction does not involve the use of heat, it is a terpenes-preserving method. You are likely to come across more monoterpenes in such an extract. One study showed that cold extraction preserves monoterpenes that are lost during supercritical carbon dioxide extraction. [1] This gives cold pressed extracts a better aroma and flavor improving the overall extract effectiveness while avoiding the presence of unwanted solvent residues. When deciding whether to go for cold press extraction, one has to make a compromise between overall yield and overall quality.
References:
[1] Sexton, M. et al. “Evaluation of Cannabinoid and Terpenoid Content: Cannabis Flower Compared to Supercritical CO2 Concentrate”, Planta Med, 2018, Volume 84(04): Pages 234-241. [Journal Impact Factor = 2.742 ] [Times Cited = 39]
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