Cannabis plants have been grown by humans for thousands of years, and the growing process hasn’t changed much. What has changed is what humans do with the mature plants. Here we’ll go over a general idea of how cannabis extracts are made.
Cultivation of Cannabis
Cannabis, like nearly all cultivated plants, begins with a seed. The grower must choose the variety of cannabis to be grown, and then purchase or harvest seeds from cannabis plants that have been allowed to go to seed. Before planting, there are a few options that must be considered: cannabis is commonly grown outside and in greenhouses and soil and with hydroponic or aeroponic methods. Hydro- and aeroponic methods often show consistently higher yields but are considerably more expensive. Soil and coco fiber growing are less expensive routes, but are less productive, messier, and require more space. Indoor growth offers more control over the environment, but outdoor growing generally produces larger plants.
These all have their benefits and drawbacks that the potential grower has to consider.
When deciding on a growing method, it’s important to consider plant selection as well. What variety of cannabis a producer intends to cultivate may make a difference in their choice of growing medium. The intended result can also make a difference in plant selection: is the producer growing for distillate production or sale as flower?
Indoor and Outdoor Cannabis Growth
Once a growing method and variety of cannabis have been chosen, it’s time to plant. Indoor growers can decide to grow whenever they like, but outdoor operations will need to take into account the seasons. Seeds are generally planted in spring when grown outdoors and germinate within around one week. As the sprouts grow into full plants, growers prune and shape the cannabis plants to encourage bushier growth instead of hard-to-manage vertical growth. As the days begin to have shorter sunlight periods or an indoor grower begins to reduce light hours, the plants enter the flowering stage.
The flowering stage is the part of the plant’s life cycle that shows the first signs of the end product. Female plants will produce flower buds that eventually become the cannabinoid-rich buds. These buds are allowed to grow for around three months until fully matured and ready to harvest, indicated by the crystalline dusting of trichomes. Buds are collected either by removing the main stem of the entire plant or removing smaller stems to choose individual buds over others that may be less mature.
After being removed from the plant, buds must be allowed to dry and cure to ensure they last as long as possible. Moisture left in the product increases the likelihood of mold growth, and curing is reported to help preserve terpenes. These elements create different scent and flavors associated with strains of cannabis.
Once the cannabis has been cured, it’s ready for sale if it’s intended to be sold as “flower”. If cannabis has been grown for distillate, oil, or other processed products, there are more steps to be taken. The producer needs to decide on a few production methods: concentration into kief, hash or rosin, or solvent extraction via hydrocarbons, CO2, or alcohol and other chemical solvents.
Cannabis Extraction Methods
Concentration is the most basic way of processing cannabis, and these methods have been used for centuries. Kief is often seen as a byproduct of cannabis grinding. When cannabis is ground, the dust of trichomes called kief collects on the grinding mechanism. Hashish, or hash, is another way of separating trichomes. Freezing cannabis buds and breaking it up over a screen allows the trichomes to separate. These are then pressed into a hash block. Rosin is made by applying heat and pressure to cannabis and results in a syrupy concentrate similar to solvent-based results.
Chemical solvent extraction is one of the most common methods used for larger-scale production, not only because it’s easily scaled up, but also due to the high investment needed for equipment and materials. Solvent extractions involve soaking the cannabis in reagents to separate the desired elements from the plant material. The solvent extraction process combines reagents with the plant material in a vacuum and then evaporates the reagent, leaving behind only the extract. The result can be an oil, gel-like texture, or a hard glassy extract. Once these have been made, they can be used in vapes or sold as material for dabbing. Learn more about Halo’s extraction methods here.