Using a blend of propane and butane, i.e. “blended solvents,” may give your process of light hydrocarbon extraction the ability to skillfully manipulate the consistency and quality of your output products.
Why Propane and Butane?
Numerous leading extraction producers choose a 30% propane/70% butane blend for budder and shatter based extractions. That enables the solvent to be able to extract fuller terpene profiles and contribute in general to a lower viscosity with a lighter color compared to a 100% butane extraction. Labs in some cases, choose to utilize 100% propane for certain specialty products such as sugar consistency products or high terpene extractions.
There are numerous things to consider when extracting using a mixed solvent blend or propane. Notably, you must consider the difference in coinciding temperatures and required pressure.
The boiling point of butane is -1 degrees C which makes it fairly easy to control the vapor pressure in a butane-only extraction since the temperature can be achieve with a small cooling power amount. However, the boiling point of propane is -43 degrees C, which requires cooing and vapor pressure that is much higher when run at temperatures that are higher than -43 degrees C.
Propane’s volatility enables the operator to distill a solvent with no or little energy needed. That translates into a recovery time that is much faster than butane. Blending solvent doesn’t accelerate the recovery time. Instead, recovery is subject to solvent that has the slowest recovery time – butane.
Many benefits are provided by using propane for both the end consumer and processor. Its low boiling point makes purging it in vacuum ovens easy and takes every little heat and time to remove it out of the end product.
Color Of The Extracts
Propane also has a tendency to extract the lighter compounds out of plant material like terpenes. The increase can be significant depending on the quality of the input material and mixes of hydrocarbon (i.e. higher terpene output is the result of higher propane mixes). That also effects the terpene’s viscosity consistency is quite low which makes the end products a lot more syrupy.
Like with most things, too much of something good can at times be bad. There is a tendency for pure terpenes to be very volatile and caustic. Therefore, a point comes where a very high percentage of terpenes may irritate the throat of the end user and be too harsh to make it enjoyable to consume. Therefore, critical to any extraction process is to have a keen eye for the end product, and to use an appropriate blended solvent balance.
Final Thoughts About Propane & Butane
Locating and maintaining this delicate blend of temperature control, pressures, and solvents, to achieve an enjoyable, consistent, and unique concentrate is more of an art than it is a science.
Therefore, trial and error and, ideally, education prior to extraction method is the key to producing the finest cannabis concentrates in the world.
Photo Credit: Subzero Scientific