Hash Church’s co-hosts are Dr. Mark Scialdone, Etienne Fontan, Collin Palmer, Fletcher Watson and Caleb Chen. They sit on the panel with the host, Marcus “BC Bubbleman” Richardson, most Sundays, alongside the week’s guests.
Marcus Richardson, the host
Marcus Richardson, known as BC Bubbleman, is the host of Hash Church and the one who started it, going live on September 28, 2014. He runs the panel, reads out questions from the chat and keeps a show that can run past four hours on track. His story is on the BC Bubbleman page.
Dr. Mark Scialdone, the chemist
Mark Scialdone, PhD, is the chemist on the Hash Church panel and one of its longest serving regulars: he was on Episode VI in November 2014 and on the first podcast episode in August 2019.
When the talk turns to chemistry, Dr. Mark is usually the one taking it deeper. He was on the panel for the episode on lab testing with Alec Dixon of SC Labs in 2019, the delta 8 episode in 2021, the dive into volatile organic profiles in 2024, and the sports medicine and mental health episodes in 2025. In March 2023 he joined Dr. Ethan Russo, Robert Connell Clarke and Skunkman Sam to remember the chemist Raphael Mechoulam.
Etienne Fontan, Berkeley Patients Group
Etienne Fontan of Berkeley Patients Group, the medical cannabis dispensary in Berkeley, California, has been on the Hash Church panel since its first year: he is named on Episode VI in November 2014.
Etienne brings the news from the legal side of cannabis. In October 2024 he shared what was happening with cannabis legalization, and the same month he was part of a conversation about kratom. He was there when Bubbleman brought the church back together in August 2020 after a long break, and he is still on the panel in Season 12, including the edibles episode in April 2026.
Collin Palmer, Vessel Life Sciences
Collin Palmer of Vessel Life Sciences is the Hash Church co-host for plant health, and has been on the panel since the first podcast episode in August 2019.
In August 2024 Collin took the panel head first into HLVd, hop latent viroid, a disease that stunts cannabis plants and cuts the resin they make. He was on the mental health episode in 2025 and the Grateful Dead episode celebrating Phil Lesh in 2024, and he is a regular voice in Season 12.
Fletcher Watson, Archive Seed Bank
Fletcher Watson, Fletch to the panel, of Archive Seed Bank is the Hash Church co-host who talks breeding.
Fletch joined the breeder Mojave Richmond in August 2024 to lay out the factors that matter in a breeding program, and that October talked through ideas for getting terpene rich rosin without the press. In May 2025 he sat in for four hours of questions with Robert Connell Clarke, and in February 2026 he was on the Season 12 episode asking what breeding really is.
Caleb Chen, the critic
Caleb Chen, the panel’s critic, is called the Highest Critic in the show notes, and he is the Hash Church co-host who curated a whole episode on music and cannabis.
That January 2025 episode brought on musicians, DJs and the people behind Reggae on the River, and included Skunkman Sam’s favorite weed song. Caleb was back for the breeding episode in February 2026 and the edibles episode in April 2026.
The wider Hash Church panel
The wider Hash Church panel changes every week. Skunkman Sam, Bubbleman’s mentor, was on it from the start; Wade Laughter, Bryon of Best Friend Farms, Josh and Kelly of Dragon Fly Earth Medicine, Mojave Richmond and Ryan Lee of Chimera Genetics come back often; and every season brings new guests. To suggest a guest or a topic, use the contact form linked at the bottom of every page.
Questions about the co-hosts
Questions about the co-hosts, answered short:
Who are the Hash Church co-hosts?
The Hash Church co-hosts are Dr. Mark Scialdone, Etienne Fontan, Collin Palmer, Fletcher Watson and Caleb Chen, with BC Bubbleman as host.
How long have the co-hosts been on Hash Church?
The co-hosts have been on Hash Church for years, some since 2014: Dr. Mark Scialdone and Etienne Fontan are both on Episode VI, in November 2014, and Collin Palmer is on the first podcast episode, in August 2019.
Are the co-hosts on every week?
The co-hosts are on most weeks, not every week: who sits on the panel changes from Sunday to Sunday, and guests rotate in.
Sources for this page
Sources for this page about the Hash Church co-hosts:
- Hash Church Episode VI, November 2014, Bubbleman’s World on YouTube
- Hash Church 2.0, Episode 20, August 2019: the first podcast episode, Buzzsprout
- Hash Church 3.0, Episode 9, August 2020: Collin Palmer from Vessel Life Sciences, Buzzsprout
- Hash Church 3.0, Episode 13, January 2021: Etienne Fontan from Berkeley Patients Group, Buzzsprout
- Hash Temple, March 2023: celebrating Raphael Mechoulam, Buzzsprout
- Hash Church 5.0, Episode 2, August 2024: Collin on HLVd, Buzzsprout
- Hash Church 5.0, Episode 3, August 2024: Fletch and Mojave Richmond on breeding, Buzzsprout
- Hash Church 5.0, Episode 8, October 2024: Etienne on legalization, Buzzsprout
- Hash Church Season 11, Episode 2, January 2025: music and cannabis, curated by Caleb Chen, Buzzsprout
- Hash Church Season 11, Episode 7, February 2025: the sports medicine episode, Buzzsprout
- Hash Church Season 11, Episode 20, May 2025: Q and A with Robert Connell Clarke, Buzzsprout
- Hash Church Season 12, Episode 5, February 2026: what is breeding, Buzzsprout
- Hash Church Season 12, Episode 15, April 2026: the edibles episode, Buzzsprout