Dr. Christopher Eskiw believes the yeast genome could be the key to your favourite brew.
Eskiw specializes in nutritional genomics — how nutrients and the environment can affect genes — with the goal of answering the eternal question of increasing the human lifespan.
He never would have imagined his research would lead him down a path to answer a slightly different question: can genomics determine why my beer tastes the way it does?
“What are the differences in yeast genomes and their genetics that creates such different and diverse beers with essentially the same starting materials?” said Eskiw.
Eskiw received $120,000 in funding from Saskatchewan’s Agriculture Development Fund for his project Connecting Craft Brewing Quality with Yeast Genomics. The research focuses on how the genome of the yeast used in brewing affects the outcomes of the beer being brewed.
“We started asking ourselves: how and why are these yeasts essentially different? And the thing that makes every organism different is their complement of genetic material, that collective entity known as the genome,” said Eskiw.
So Eskiw asked one of his grad students who worked for 21st Street Brewery to introduce him to head brewer Casey Murray, who walked Eskiw through their process of brewing beer.
But Eskiw — an associate professor of nutrigenomics with the University of Saskatchewan’s (USask) College of Agriculture and Bioresources — wanted to dig deeper. Of the basic ingredients of malt, hops, water and yeast, Eskiw was convinced that yeast was the key.
“A lot of these beers use different yeast strains. So you start with very similar starting materials, and the yeast converts them into very different final products,” he said. “Whether it be a fruity citrus flavour or a dry lager flavour, that is dependent on the yeast strain.”
Nutrients, the environment, and the human genome
Eskiw studied at the University of Alberta and USask before earning his PhD in Cell Biology from the University of Toronto. His specialty is nutritional genomics — or put more simply, the study of how genes respond to and are influenced by different nutrients.
“This is the study of gene-nutrient interactions, which is an equally cryptic term,” said Eskiw with a laugh. “Nutritional genomics is identifying the necessary compounds that help promote the healthy genes to turn on and the detrimental genes to turn off.”
As Eskiw puts it, most people don’t quite understand the details of how genes work when they refer to their own genetics.
“Most people don’t realize the environment plays a huge role in how your genes are regulated. Diet and nutrition are the number one environmental factors controlling when your genes turn on or turn off.”
Eskiw’s current project is based on the concept that the way different genes express themselves can be influenced by their environment. An example Eskiw used involved drinking coffee: one specific gene controls caffeine metabolism. If the gene is “activated,” you metabolize caffeine more quickly. Alternatively, if the gene is expressed differently, you metabolize caffeine more slowly and its effects are longer-lasting.
But Eskiw said it’s possible to “activate” that caffeine-metabolizing gene by ingesting caffeine with enough regularity — changing the “environment” of the gene.
“Saying ‘oh, it’s my genetics, I just have the gene for it’ — that’s a misconception. What you do and where you are helps define how those genes are expressed.”
It’s this theory that Eskiw is applying to his research into yeast genomics. Eskiw believes it’s the yeast in beer that has the greatest control over the final product — from colour, to smell, to taste.
So if genes can be influenced by the environment, and the taste of beer is influenced by yeast, Eskiw’s theory is that they can look for and influence the parts of the yeast genome that correlate to particular flavours and colours of beer.
“If you ask me any biological question, I’m going to come back to the genome … When you add different software, it does different things. With that yeast, we’re maybe adding different pieces of software, but we’re turning them off and on at the right time.”
Beer, genetics, and you
The process for brewing craft beer is, at least on paper, fairly straightforward. There are only four basic ingredients: malt (or malted grain, typically barley, to be specific), hops, water, and yeast.
The brewing process starts by adding malt to hot water to begin turning the starches in the grains into fermentable sugars. Hops are later added to the newly created sugar water – also called “wort.” Once the hot combination of wort and hops is rapidly cooled, yeast is added to ferment the brew — converting the sugar into alcohol and carbon dioxide.
First, Eskiw’s team will examine and record the genetic profile of yeast samples. Next, the team will match those profiles to flavours of beer they create.
And finally, they will attempt to activate or deactivate specific genes to determine how the final flavour profile is altered by the yeast genomics.
The goal is to create a roadmap for craft brewers — a “handbook” for breweries to know exactly what kind of beer they’re making. It would also provide a scientific method to determine what smaller-scale brewers can do to get different, and very specific, flavours of beer.
“(Brewing) is more of a traditional observation science. We started with this and we got that, so we’re going to keep doing this and hopefully we’ll keep getting that product. But if something goes wrong and you’re not sure about the mechanisms behind it, it’s hard to correct,” said Eskiw.
A growing Saskatchewan industry
The importance of yeast in brewing isn’t a brand-new concept. Many large-scale brewing companies keep a firm proprietary hold on the yeast and the methods they use to produce their types of beer.
“Not many people have actually looked at this,” said Eskiw. “Those that have looked at it, work for major breweries. And they’re not telling anybody anything … we want to kick the lid off the can here.”
Eskiw’s research could take the guesswork out of the process when it comes to yeast. A more targeted recipe using yeast with the exact right genetic markers activated would lead to less waste, lower costs and a greater diversity of product for home-grown brewers.
Eskiw lauded the craft brewing community in Saskatchewan for their passion for the craft, as well as their support of his research. Calling it a “very Saskatchewan industry,” Eskiw said he hoped he’d be able to give local brewers an advantage with his research.
“Knowledge is power. I think this would give the craft brewers more variety because they could take that same yeast, change the growth conditions a little bit, and generate a different beer. So everything’s the same starting material, but now you can make more products with it.”
Craft brewers throughout Saskatchewan have given Eskiw and his research their support. 21st Street Brewery has become an integral partner in the brewing part of the project, and Eskiw said Maker’s Malt in Rosthern has been providing the malt for their experiments. Meetings with Nokomis Craft Ales (another craft brewery) and JGL Shepherd Farms (a local producer of hops) were on the horizon at the time of the interview, and he’s hoping to add more collaborators going forward.
As Eskiw put it, his health sciences research doesn’t always pique local interest. This time, the community is very interested — and Eskiw is happy to share a pint with them.
“I’ve lived in Alberta, Ontario, I lived in the UK for 10 years. Saskatchewan has a different feel in its communities. It’s very much a tight-knit province, and the craft brewers exemplify that … I’m super excited to be involved with this.”
Thank you to College of Agriculture and Bioresources for submitting this article and photos
Photo: Casey Murray, Head Brewer of 21st Street Brewery; Dr. Christopher Eskiw; Fina Nelson, PhD student.