Theories of Thiol

[Edit May 16, 2025] Sadly, Omega no longer offers thiolized yeast to the homebrewing market.

Q: What’s the deal with this “Thiolized” yeast I keep hearing about?

A: It seems impossible to avoid mention of new strains of yeast that have been “Thiolized” through some fancy-pants science stuff. But what does it all mean?

First, we have to understand what thiols are. In the simplest terms, thiols are aroma compounds that produce flavors of grapefruit, passionfruit and guava. Thiols exist in low levels in some hop varieties, and the precursors that create thiols are abundant in malted barley and wort. But those precursors need to react with yeasts that have a certain kind of beta-lyase reaction to produce levels of tropical fruit flavors that are noticeable in a beer. Not all yeasts produce that reaction, meaning not all yeasts are capable of producing those thiol-driven flavors.

Enter the mad scientists of Omega Yeast. Through DNA sequencing technology, their researchers have identified the genetic markers that produce thiols. Then, using CRISPR technology that allows scientists to genetically modify a living organism’s DNA, they began adjusting the genes of common yeast strains to boost their thiol-producing capability. Hence, “Thiolized.” (The actual term “Thiolized” is a registered trademark of Omega.)

Omega currently offers four Tholized strains:

• Cosmic Punch is a Thiolized version of their British ale strain.
• Star Party is a Thiolized version of their West Cost ale strain.
• Lunar Crush is a Thiolized version of their Mexican lager strain.
• Helio Gazer is a supercharged version of Cosmic Punch, based off the British ale strain.

Learn more about the science behind Omega’s thiol-driven DNA tech here. And remember you can pick up these and other new yeast strains at Brewhound Supplies!