Decay of Organic Compounds
There are several factors to consider when preforming any kind of organic chemistry; organic matter will decay and deteriorate naturally over time. Therefore we put produce into the refrigerator/freezer to extend its longevity. Refrigeration lowers the temperature and slows down the natural process of decomposition or the breakdown of organic compounds. Heating will produce the opposite result.
When we cook food – we break down matter in a menagerie of fats, salts, acids – cooking is not unlike distillation – it’s basically chemistry we preform every day in order to survive! Understanding how to speed up and slow this process is essential to distillation and extraction of cannabis concentrates in general.
Another factor to consider is what’s in the atmosphere. The very air we breathe contains a powerful compound which interacts with organic and non-organic matter producing subtle changes – it’s called oxygen and it causes a phenomenon called oxidation.
Oxidation is the process when oxygen combines with an element changing its appearance and chemical composition. When iron reacts with oxygen, it changes to rust – this is an example of oxidation. When fire burns up a wooden log, this is also an example of oxidation. This is also true for organic matter – such as cannabis resin etc. Heat can speed up this process considerably because the molecules become more excited and can move around freely. Therefore, it’s important to distill cannabinoids in an environment devoid of all oxygen, especially when we subject our resins to heat.
Most extraction is done under very cold conditions, but sometimes it’s necessary to apply heat. In the case of cannabinoids however – applying too much heat would vaporize them into a cloud i.e. smoking flower – so how do we capture and re-condense this vapor into a concentrated form?
Vacuum distillation is used when the boiling point of the desired compound is difficult to achieve or will cause the compound to decompose. THC for example has a boiling point of approx. 425C at atmosphere – but if we were to apply that kind of heat without vacuum, everything in the resin would be turned into dust! It is only at 300 micron or 0.3 mTorr that we can fraction off THC at a reasonable 184C. 157C boiling point can be achieved at 50 micron or 0.05 mTorr.
Why is this important? The journey of extraction and distillation will subject our wonderful cannabis plant to many of these conditions and it’s important to understand what is happening to the cannabinoids and terpenes during the process and how they are affected. Knowing all the variables of decay and decomposition allows us to create conditions which allow us to improve efficiency and boost yields of the specific compounds we are looking to isolate.