Photography courtesy of Omega Yeast
With thiolized yeast there are so many different levers you can pull, so Burns and Capps have a few key pieces of advice.
Test, Test, and Test Again
The best advice Burns can give brewers interested in utilizing thiolized yeast is to experiment with smaller batches.
“One of the things I think is really helpful is if you’re running your typical IPA recipe on the brewhouse, just pull off some wort before you pitch your yeast, get a small pitch of one of these new strains, and try it out,” says Burns. “Just mimic your recipe with your house yeast and one of the new thiolized yeasts to see how it changes the beer.”
Overall, even as Omega Yeast’s research has developed, they’ve discovered that different raw materials bring different thiols into the equation. Some could be hop derived—creating sharper grapefruit or even dank aromas depending on the hop.
But others could be malt derived—adding more passion fruit aromas.
“When you’re looking at these new strains, just realize there is quite a bit of variability in recipe design that will impact how these beers come out,” says Burns. “Try pulling off some wort from your main beers and doing a little test trial ferment to see how you like it.”
Capps agrees that actually testing different recipes and working with different variables is key here.
He’s been trying to get a little less in the weeds on all the research data and technical advice and a little more back to playing around with different recipes. “I listen to my mouth because ultimately what matters is how the beer tastes,” says Capps. “I can talk a mean science game all day long, but if the beer tastes like tropical toilet water it doesn’t matter.”
Since there are so many facets to understand and play with here, Capps started four different series of beers at New Image dedicated to just one component of research around thiols and thiolized yeast.
Three of those series move the needle faster by incorporating bigger changes.
But one series called Phanny Pack culminates all of Capps’ trials into one now-flagship, year-round series utilizing Cosmic Punch.
With Phanny Pack, “this is a beer that we are brewing with the least batch-to-batch changes in order to really understand the impact of each change,” says Capps, who notes they brewed five different versions before actually settling on what they’re calling the Core. “We modify the Core based on what we’re learning from the other series…but we move more slowly and gradually with Phanny Pack to dial in those changes.”
Meaning what New Image produces is a beer that is, to the best of its ability, optimizing thiols and thiolized yeast based on what Capps has read, studied, and implemented in his own beers.
Because at the end of the day, it’s “ultimately, how does the beer taste?” says Capps. “We’re not producing thiols, we’re producing beer that tastes good… That’s the grain of salt that everyone should have in the back of their mind. You don’t want to make a faster plane if the plane is just crashing.”
In Capps’ opinion, Phanny Pack is currently the best beer New Image is making with the thiolized yeast strain Cosmic Punch. “We’re putting all the best practices into that beer at any given time and brewing it consistently,” says Capps “We’re growing in our own knowledge of using thiolized yeast and thiol precursor products to produce the best IPA we know how.”
Photography courtesy of @nibrewing | New Image Brewing
Consider Changing Out Your Grist to Include Wheat and Oats or Blending Yeasts
Knowing that different thiols come from different raw materials can be helpful when altering a recipe that uses thiolized yeast.
If you’re looking to dial back the intensity of the thiols, you can actually include more wheat and oats in your grist.
Research has shown that wheat and oats do not contain a high amount of these free or precursor thiols.
So for example, “if you want to add nuance with the Helio Gazer, you can balance it out by changing your grist because all of that thiol precursors are coming from the barley malt not wheat and oats,” says Burns.
You can also consider blending thiolized yeast with a house strain at a ratio that gives you the right amount of thiol output.
Again, it all goes back to trial and error, pulling certain levers to find what works best.
Try Mash Hopping
On the other hand, if you’re looking to maximize your thiol conversion and aroma output, consider mash hopping.
An idea of front loading your mash with hops, mash hopping essentially provides your wort with more of the hop thiol precursors for the thiolized yeast to convert during fermentation into thiol aroma.
Essentially with mash hopping, you’d want to add hops reported to be very high in thiol precursors—Cascade, Saaz, Calypso, and Motueka, for example—to the mash. “These are all hops that have three times the level of precursors as some other varieties,” says Burns. “We have really solid data to show that…we’re seeing a twenty to fifty percent increase in thiols in fermentation with mash hopping.”
Burns recommends that mash hopping really works best when using a thiolized yeast such as Cosmic Punch “that is pretty versatile when you’re trying to get the most thiols into fermentation,“ she says, cautioning that “it’s probably not as necessary with the newer strains because they’re already so potent that you don’t need to pull that lever.”
Consider the Law of Diminishing Returns here. Strains like Helio Gazer and Star Party can unlock thiols in the 5,000 parts per trillion. So when you’re talking about a twenty to fifty percent increase in thiols, you’re already so far above the sensory threshold there that mash hopping isn’t worth the squeeze (you don’t just want to waste hops in the mash if you don’t need to).
With Cosmic Punch, on the other hand, that registers thiol production around 500 parts per trillion, according to Burns, mash hopping gives a bigger bump that has a more significant impact.
