Extraction Considerations and Advice from a Leading Researcher

January 11, 2019
Abstract / Synopsis: 

There are many factors to consider when starting an extraction method in cannabis—from flower supply and which method to use to particle size and flower to solvent ratios, among others. With all of these factors to consider, it might be hard to find a starting point. We recently spoke to leading extraction researcher Dr. Markus Roggen, Founder of Complex Biotech Discovery Ventures, about his experiences in the industry and what extraction methods he has used. Dr. Roggen also offers his insight into what to consider first in an extraction as well as his next research projects and plans for the future.

How did you get involved with cannabis extraction?

Dr. Markus Roggen: Pure serendipity! In 2014, I finished up my postdoc in physical organic chemistry at The Scripps Research Institute in San Diego and was looking for what to do next when my triathlon coach introduced me to a group that needed a chemist to run their analytical laboratory for cannabis. Initially, I was hesitant to leave a classical chemical career for the still young cannabis industry. Although, I was intrigued by the research and discovery potential in the field, so I did move into a totally unknown industry and culture (for me). While I worked as a laboratory director, on the side, I was mentoring young startups at Canopy Boulder and San Diego. At one of their networking events, I was explaining the scientific fundamentals of CO2 extraction (you know as you do over a good drink). The CEO of OutCo, a fully vertically integrated medical marijuana producer in San Diego, happened to be listening. He offered me the chance to join his team to put theory into practice. So, I did. I started leading the extraction and production processes in late 2016.

Do you prefer one method of extraction over another?

Roggen: No, my focus is on the required output! If the local regulations only allow ethanol extraction, then this is the best solvent to use. If the concentrate product is focused on solventless connoisseurs, rosin press or ice water hash might be best. But if I consider control over the extract composition paramount, then I highly recommend supercritical CO2 extraction (supercritical fluid extraction [SFE]) equipment. Due to the solvent properties of CO2, one can modulate which compounds are selectively enriched and how the extract properties are set. That allows one to, for example, separate terpene fractions from cannabinoid oils, or even enrich one cannabinoid over the other.

What are the major things to consider before starting an extraction?

Roggen: How much time do you have? The most obvious things to consider are flower supply and extraction method, but there are many, many other factors that influence the extraction outcome. For example, my research has shown that the particle size distribution impacts extraction precision and efficiency in SFE. For ethanol extraction, it’s the ratio of flower to solvent that has an effect on efficiency—and it’s opposite what one might think: More solvent extracts less THC! I could go on and on, so I will just name a few others: cannabinoid concentration, terpene concentration, water content, particle size, temperature, pressure, time, production costs, production volume, and most important product needs.

What is the biggest obstacle to overcome in cannabis extraction?

Roggen: Overcoming fixed mindsets. The debate over which solvent is best feels like a religious war. Although, there are enough deities for everyone, and those represent the regulatory, economical, and customer powers of the market. There likely is space for every technology, but there is no space for stubborn dogmatists.

  1. M. Roggen, Cannabis Industry Journal, August 3, 2017, https://cannabisindustryjournal.com/column/clear-vs-pure-how-fallacies-and-ignorance-of-extraction-misrepresent-the-cannabis-flower/.
  2. M. Roggen, Marijuana Venture, October 30, 2018, https://www.marijuanaventure.com/rethink-extraction-cultivation-methods/.

How to Cite This Article

M. Roggen interview, Cannabis Science and Technology 2(1), 54-55 (2019).