The Colorado Brewers Guild hosts Collaboration Fest on Saturday, March 25, from 2 to 6 p.m. at The Westin Westminster to bring 175 participating breweries together with over 125 unique beers to sample. We look forward to this one-of-a-kind event each year that pairs CBG member breweries with other beer establishments from far and wide, to present some of the most original brewskis you’ve tasted in a hot minute.

In addition to celebrating the camaraderie of craft beer, Collab Fest is notorious for funky, experimental styles and capitalizing on up and coming beer trends. We’re seeing a big push this year towards thiolized beers, a beer “made with thiol boosters or thiolized yeast strains,” explains John Giarratano, at Inland Island Yeast Laboratories, who speaks to this fascinating direction in a blog post originally published by the CBG.

“For decades, brewers have been pushing the flavor envelope by designing the bitterest, juiciest or most interesting beers through the addition of more and more hops, and then through the addition of newly developed hops, purposefully bred for specific traits like tropical fruit aroma,” says Giarratano. “However, there are limitations to how many pounds of hops can be added to a given volume of beer, and new hop varietals take years to develop. Brewers were asking for another tool to use when trying to push recipe innovation. Lucky for brewers, scientists also like beer so something awesome was bound to happen.”

All together now: Science & art = beer

We dig on some weird science and believe that the evolution of beer hangs in the balance of honing in on classic styles while still exploring innovative ways to bring forth subtleties and nuanced flavors. Let’s dive into the cool nerdy stuff to better understand why thiol beers are expanding the landscape this festival season and in craft beer as a whole:

“It was understood that plants such as guava and passionfruit, but also including beer ingredients like barley and hops, produce a flavorless molecule called Glut-3MH,” explains Giarratano. “Through the activity of naturally occurring plant enzymes, Glut-3MH is converted into a flavor-active thiol called 3MH. Simply cutting into fruit like guava and passionfruit is proof that these plants are very efficient at converting Glut-3MH to 3MH. However, due to low enzymatic activity, traditional beer ingredients like hops and barley are not efficient at the conversion. This is where science steps in and yeast is developed through genetic modification or breeding that increase enzyme activity and help to convert flavorless compounds like Glut-3MH into potent flavor-active thiols like 3MH. This process is generally called thiol biotransformation and is capable of increasing 3MH production by >100X in some cases. This has also allowed brewers to use hops that were not seen as being high in tropical flavors, but actually have high levels of unlocked Glut-3MH, to make tropical fruit flavor driven beers.”

See? Learning is fun!

We’re jonesing for the end of March when we plan to make a beeline for craft breweries jumping on the Thiol-train, to include:

Want to join us at the coolest science fair you’ve ever attended? Lez go.

Tickets for CollabFest are on sale now and can be purchased here. General admission tickets are available for $65 with entry at 3 p.m. and early access tickets will run you $85 with the added bonus of getting an hour-long head start, starting at 2 p.m.

Established in 2014, Collaboration Fest is one of the CBG’s largest fundraisers, so come support the local scene, support progress and togetherness while experiencing some very tasty and exclusive beers. Then, stay safe. We highly recommend taking advantage of the onsite group rate at the Westin Westminster for just $109 per night, if you book by March 10.

“A new frontier beer recipe experimentation now exists where a balance between Glut-3MH availability and thiol biotransformation is key,” says Giarratano. “From obscure sources like the ground up skins of Southern Hemisphere Pino Grigio grapes, new ‘thiol boosters’ have been developed to flood a beer with flavorless thiol precursor and push as much thiol biotransformation as possible. Even beer styles like lagers, lending themselves to clean and crisp flavor profiles, are now getting the thiol booster and thiolized yeast treatment, creating a new spin on old styles.”

Images courtesy of Dustin Hall, The Brewtography Project