This is typically the last stage where a well-designed HVAC system for cannabis grow operations is heavily involved. When the plants are harvested, roughly 75% of the plant’s weight is water; that is typically reduced to about 10% to 12% for dried flower product applications. It is also critical to preserve the cannabinoids throughout the drying process, as well as the ''terpenes'', the fragrant oils that give the end product its unique aromatic profile. Drying the flower also helps to mitigate anything biological such as mold spores from landing and propagating on the product.
The primary goal of the drying process is to remove water from the finished product. At the time of harvest, the cannabis plant has a moisture content of roughly 75% to 80%, meaning that out of 100 grams of harvested material, 20 to 25 grams is plant material and 75 to 80 grams of that is water. Dried flower is generally dried to a moisture content of 10% to 12%, meaning that the same 100 grams of undried material is finished drying at a weight of 22 to 28 grams, a total weight reduction of nearly 75%.