Introducing Star Party

Star Party is designed to enhance thiol biotransformation while retaining the clean fermentation profile and clarity of its parental strain, West Coast Ale I (OYL-004). This latest Thiolized strain will add a big burst of thiols that’s perfect for redefining classic styles, juicing up a West Coast IPA, or creating a unique style that highlights the thiol potential of regional hops and malt.

Discover the unrecognized potential of your raw materials

Malt is rich in precursors that spring forward as passion fruit and guava, while hops can even bump up their dank character when they interact with Star Party. Many brewers have begun adapting Cosmic Punch as a house strain thanks to its versatility and utility when used in conjunction with mash hopping. Star Party takes these traits a step further, creating an intense concentration of thiols sure to stand out among aromatic hops. This strain was engineered to be more intense — try a simple mash hopping approach along with your favorite base malts and experience firsthand the extent of its biotransformation capabilities.

A new way to release thiols

After discovering the possibilities for thiol release while working on Cosmic Punch, our R&D team decided to look outside of yeast for other β‑lyases in nature with high specificity to cysteine-thiol precursors like those found in malt and hops. We hit the books and the literature pointed us to a bacterial β‑lyase called PatB. This enzyme is found in many bacterial species, but we found that PatB from S. hominis—a bacteria that occurs commonly all over our bodies as part of our skin’s microbiome — gave us the greatest levels of passion fruit and guava notes when used in brewing trials.

The bacterial PatB behaves very similarly to the yeast β‑lyase Irc7, meaning it cleaves cysteine-thiol precursors found in malt and hops, effectively making those flavor-active compounds available for us to enjoy. However, PatB is more active and more specific than Irc7, making it an exciting addition to a brewer’s arsenal of tools to create interesting flavor combinations.

Star Party was engineered using CRISPR/Cas9 gene editing technology to insert patB into a classic Chico (West Coast Ale I) strain. Before we conduct any brewing trials with these modified strains, we confirm that the gene editing was targeted successfully and that there were no off-target effects. We’re incredibly excited about the doors that PatB has the potential to open and we can’t wait to see (and taste!) what you all create.

Fun fact: Scientists use nomenclature rules to indicate when they are referring to genes or proteins. For example, Irc7 and PatB refer to the protein, and IRC7 and patB refer to the genes.

Our engineered strains undergo thorough characterization and evaluation to confirm that the process of gene editing and the resulting application of the engineered strain to beer fermentation is safe for the intended use. The β‑lyase PatB expressed in Star Party is derived from S. hominis, a bacteria that is abundant on your skin and is a natural protectant against harmful bacteria. The levels of thiol compounds released by PatB in beer are within the natural range found in Sauvignon blanc wine and tropical fruits like grapefruit, guava, and passion fruit. We engineered Star Party using CRISPR/Cas9 and have confirmed through molecular biology techniques that the patB was targeted to a very specific site in the genome and no off-target effects occurred. After the gene editing has occurred, the CRISPR/Cas9 machinery is removed. The benefit to expressing patB in brewing yeast is that brewers have an option to remove the yeast, and thus remove the enzyme. Naturally, the yeast will settle, autolyse, and degrade the PatB post-fermentation. If you have any questions or concerns, feel free to contact us at info@omegayeast.com.