How is CBD extracted form hemp?

There are several ways to extract the valuable compounds from Hemp. The most common methods used by commercial producers are:  

Liquid Solvents: Usually Butane, isopropyl alcohol, hexane or ethanol, they are passed through the plant matter to remove cannabinoid and flavours. They are then transferred to the liquid which is in turn evaporated away to leave concentrated chemicals and flavours in oil form. There are however some concerns surrounding this extraction method as Liquid  

Solvents can leave trace impurities. 

CO2 Extraction: Utilizing a ‘Closed Loop Extractor’ this form of extraction is very gentle and is fast becoming the preferred extraction technique. CO2 can exist as a solid, liquid or gas this allows for variables in pressure and temperature to be manipulated to extract the compounds that you require and discard the ones you do not. Unlike extraction using Liquid Solvents there is minimal risk of contaminants. 

Water Extraction: New techniques are emerging that retain more of the plant’s beneficial compounds. Cannabinoids and Terpenes are extremely temperature and pressure sensitive, therefore cold-water extraction enables the retention of a much greater proportion of these compounds through the extraction process, and therefore a better end product.