Definition - What does Open-Loop Extraction mean?
In the cannabis extraction industry, open-loop extraction is the opposite of closed-loop extraction. It typically refers to an open-tube butane run.
For example, making butane hash oil (BHO) in an open-extraction system involves placing the plant material into an open-ended tube and running the butane through the tube and across the plant material to extract the concentrated oil of the plant fiber.
Using open-loop extraction exposes the final concentrate product to the butane that is being used as the solvent. This causes the cannabis concentrate to contain a solvent residue.
Hydrolife explains Open-Loop Extraction
Open-loop extraction of butane hash oil was once common. However, the exposure to the solvent often leaves a residue on the concentrate, which makes it unworthy for many medical marijuana and pharmaceutical applications.
Cannabis connoisseurs have also started to steer away from using cannabis concentrates that contain even small amounts of butane residue from open-loop extraction methods.
Nowadays, closed-loop extraction methods are considered far superior for creating concentrated products that contain little or no solvent residue. Another way to create non-solvent concentrates is to use a non-solvent extraction method, such as dry sieving.