Water Based Extraction of Cannabis
Two Main Water Based Extraction Methods
Both use a solvent-free concentrate which customers are often looking for.
Cold Water Extraction
1. Water extraction utilizes a solvent-less method of extraction that submerges finely chopped cannabis plant material in freezing water.
2. The plant is stirred in the cold water causing the trichomes to separate from the plant.
3. Once the trichomes fall off of the plant, it will pass through a series of screens.
The end result is a product that has 50% to 70% THC levels.
Hot Water Extraction
Pressurized hot water offers the advantage of being a safer alternative to other extraction methods.
Protocols developed to select against THC.
The optimal conditions to extract more CBD, CBC, and CBG than THC and CBN were set at 150 °C, 160 °C, and 45 minutes as extraction temperature, the temperature at collector vessel, and the extraction time, respectively.
Description of Pressurized Hot Water Method
The desired sample is placed in the cell for extraction
The cell is then heated to a predetermined temperature
The system is then filled with water and pressurized
The sample is then kept at these exact conditions until sufficient breakdown of solutes is achieved
The used solvent is then let out of the cell, and an extraction solvent is forced through the system for a predetermined time known as dynamic extraction time.
The resulting sample is then rapidly cooled in ice water using glass flasks to prevent degradation of the extract.
Resulting End Product
Trichomes are what is removed.
This closed loop system will produce a thick goopy substance ranging from yellow to brown.
Different temperatures and pressures will result with different end product consistencies.
THC levels range from 70-90%
Advantages of Water Based Extraction
Elimination of additional sample clean up
Reduction in organic solvent consumption
Ease of automation
Cheap solvent (water)
Disadvantages of Water Based Extraction
Relatively expensive start-up cost
Long residence time of extracts has an increased risk of phytochemical degradation.
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