At Family Farms, we have been focused on providing plant oil extraction products and methods that are safe in terms of production and consumption. The term “Clean Extractions” has been a rallying cry for us. We feel that oils that will be used for therapeutic purposes, or for use in food production, should be as safe as possible and contain no trace of the solvents used during the extraction process. We also feel that people who wish to produce plant oils should be able to do so without putting themselves or others at risk by using volatile and dangerous solvents. To put it bluntly, we feel that butane, and other dangerous solvents, should be removed from the conversation as an option for oil extraction.
In addition, we have also focused on creating processes that are optimized for maximum output.
This research has resulted in a two-stage process. The first stage removes the trichomes from the plant surface using dry ice sublimation. The trichomes hold the essential oils that we seek. By removing the trichomes, we reduce the amount of plant material that we have to process through secondary solvent processes such as supercritical CO2. This allows us to achieve quantities of scale by processing just the plant oil located in the trichomes, versus processing the entire plant material.
STAGE ONE – DRY ICE SUBLIMATION
What is Dry Ice?
Dry ice is frozen carbon dioxide (CO2), a natural occurring gas. CO2 is found in our atmosphere and is used by plants as part of the photosynthesis process. Mammals also expel CO2 when exhaling. Dry ice is produced by placing CO2 under high pressure and low temperatures of -109.3 Fahrenheit (-78.5 Celcius). Dry ice is commonly used for food storage and for flash freezing.
By it’s very nature, dry ice wants to convert back to it’s original gas state. This process is called sublimation: the process of a solid converting to a gas while skipping the intermediate liquid state.
Sublimation as an extraction solvent
The sublimation of dry ice can not be stopped, only slowed by proper storage. However, for our purposes, we want to expedite the process to produce a flash freeze environment. The Extraction Contraption maximizes the sublimation process in several ways. First, the tumbling action breaks the dry ice crystals apart, enhancing the sublimation rate. In addition, the stainless steel acts much like a martini shaker in that it helps create and hold cold air inside faster than other materials such as plastic. More importantly, stainless steels does not degrade from the frigid environment like many other materials. When using plastic or cheaper materials you run the risk of degraded particles from the container making their way into your plant extraction, which could have unhealthy consequences.
How trichomes are harvested
Simply put, the process described above flash freezes the trichomes from the plant in a very short amount of time. The trichomes from some plants, such as lavender, can be harvested in ten to fifteen minutes. Hardier and smaller mass plants such as pine needles can take up to 30 minutes.
As the plant matter and dry ice tumble, several things are occurring. First, as mentioned, the internal temperature drops dramatically, and freezes the trichomes, forcing them to snap cleanly off the plant. Second, the sublimation process creates a small amount of pressure, which helps push the lighter material, the newly freed trichomes, forward. This, combined with the centrifugal force of the tumbler, help push the trichomes through the specially designed nylon screen. In addition, a very arid environment is created, which removes much of the moisture around the trichomes. This results in a very dry product that needs very little curing, if any, depending on your ambient humidity.
STAGE TWO – SECONDARY SOLVENT
Depending on your application, you may use the trichomes harvested in the Extraction Contraption directly. For example, rosemary trichomes are excellent for cooking and baking. Lavender and pine trichomes are perfect for scent based applications such as potpourri. However, many applications require that the waxes and other elements of the trichomes be removed, leaving just the essential oil. This requires a secondary solvent. While there are many solvents on the market, we recommend the following three for creating a clean, solvent free oil extraction: steam distillation, ethanol and supercritical CO2.
Steam distillation of essential oils has been around for hundreds of years and is still common today. The type of plant trichomes you process using steam distillation will be governed by several factors including the sensitivity of the essential oil to the action of heat and water, the water solubility of the essential oil and the volatility of the essential oil. Friendly Farms provides several type of steam distillation units and you can custom order large industrial units as well.
Ethanol extraction is an efficient solvent for removing waxes from the trichomes. It is important to note that we DO NOT endorse the use of isopropyl alcohol as it a petroleum based product and is not meant for human consumption. We recommend using high proof (185-190 proof) grain alcohol. The Extraction Contraption has the ability to convert to a distillation unit for the reclamation and distillation of grain alcohol. We do not endorse violating state or federal distillation laws. Biofuel permits can be obtained to produce solvents legally and safely.
Supercritical CO2 extracts plant oils by placing the plant trichomes under extreme pressure with CO2 gas. Friendly Farms provides the SuperC machine as an inexpensive supercritical CO2 extraction option. Like dry ice, supercritical CO2 does not introduce any other chemicals into the extraction process, making it an excellent choice for therapeutic and food grade applications. In addition, supercritical CO2 allows you to target specific profiles in an essential oil by adjusting the temperature and pressure of the extraction process. *