Having a Beer with Richard Preiss

We had the opportunity to sit down with Richard Preiss, co-founder of Escarpment Laboratories and developer of LalBrew Pomona™, to get his thoughts on all things biotransformation and what new trends brewers should look out for.

The discussion around biotransformation started with terpenes, and then everyone became interested in thiols. What is the next frontier in biotransformation?

It may be wishful thinking, but I think the next frontiers are precision and balance rather than maximizing output of one aroma compound. At this point, science has figured out how to push thiols and terpenes to extremes in beer. Now, I think the game becomes finding the right balance in the brewery to achieve targeted flavor profiles such as peach, passionfruit, pineapple, and so on. Or create entirely new flavor profiles using yeast biotransformation. 

We may also see more discussion about lactones, a class of aroma compounds present in beer that has not yet received much attention.

What are lactones and why should brewers care?

Lactones are aroma compounds that are produced and modified as a byproduct of fermentation. They can originate from malt or hops. On their own, they can present as dairy or coconut notes. However, lactones are synergistic with other aroma compounds and, when they combine with esters and terpenes, they can present more complex aroma profiles such as stone fruit (peach, apricot). 

We are still in the early days of understanding how different yeast strains push lactones in beer, but early data suggests there are differences among strains that might push one yeast to make a “peachier” beer than another. 

What is the first thing you would recommend to a brewer looking to achieve better biotransformation?

Don’t ignore your whirlpool hops! I see a lot of modern IPA recipes with a tiny whirlpool addition and a huge dry hop. Even if you’re dry hopping mid-ferment, you’re leaving out on a lot of biotransformation potential by skipping a heavier whirlpool. Adding hops to the end of the boil/whirlpool will help solubilize a lot of the precursor compounds that yeast can biotransform such as bound thiols, esters, terpenes, and lactones. 

Any hop high in geraniol (e.g. Centennial) can potentially present as more citrusy when biotransformed. Hops perceived as coconut-like (e.g. Sabro) can gain added complexity that pushes the profile toward stone fruit and pineapple. Hops with high levels of “dankness” (e.g. Columbus) can become fruitier. 

LalBrew Pomona™ was produced through a combination of yeast breeding and lab evolution. How did each of these methods select for specific characteristics of the LalBrew Pomona™ strain?

With LalBrew Pomona™, we were deliberately trying to create new yeasts for IPA or hop-forward beers. So, the target was to develop a yeast strain with efficient fermentation, compatibility with modern hazy IPAs, and a unique flavor profile to help brewers create new beers. 

We first did yeast breeding to combine two strains we liked. There was an efficient parent and a flavorful parent, basically. We did yeast breeding to generate hybrids of the two strains and found some hybrids we liked during screening, but they missed the mark in terms of haze stability and fermentation efficiency. 

That led us to follow breeding with adaptive laboratory evolution, which can be thought of as strength training for microbes. The hybrids were forced to grow in and ferment hazy IPA wort for more than 45 generations. This process selects for random mutations that give the yeasts a fitness advantage.

At the end of the process, we screened the yeast candidates that made it to the end, and our favorite became LalBrew Pomona™. 

If a brewer is using LalBrew Pomona™ for the first time, what are the key parameters they should consider when using this strain? Specific hops? Addition times?

I like to think of LalBrew Pomona™ as Swiss army knife for hoppy beers. There are a lot of different things it can do in terms of flavor production. That being said, we’ve seen some winning combos based on beers we and our clients have brewed: 

You can also experiment with other ingredients and styles that have biotransformation potential. For example, coriander seed can produce surprisingly potent lemon-lime aromas when biotransformed by a yeast like LalBrew Pomona™. 

Crystal ball gazing, what trends do you think brewers should look out for in the coming years?

I personally want to see more low-ABV beers as an option for mindful consumers. Non-alc beers are really hard to nail and involve a lot of compromises in taste. I think many consumers (myself included) would support more commercial beers in the 2-4% ABV range if brewers put effort into making them taste good. Most ultra-session beers need improvement in flavor and body.  

What is your secret superpower?

I bake a lot of bread as a hobby. Several hundred loaves in, I think I’m close to perfecting a focaccia recipe. Yes, even my hobby involves yeast. 

About Richard Preiss

Richard Preiss, co-founder of Escaprment Laboratories, is an active brewing scientist and long-time homebrewer. At Escarpment, Richard’s focus is on translating new research into exciting products and knowledge for brewers. Richard loves to help their team and the brewers we work with to solve problems, overcome challenges, and unlock efficiencies.