Every few weeks, Sophie writes about Beer, Brewing and Bites. Her stories are witty, educational and worth a read!
November 24, 2017 - Wild Yeast, A Taste of Place
This past October, Nova Scotia Business Inc. (the province’s business development agency) awarded a $15,000 research grant to the Saltbox Brewing Company in partnership with researchers at Acadia University’s Department of Biology. The objective: to investigate specialized yeast strains endemic to Nova Scotia that could be used to create unique, regionally-flavoured craft beers.
Now you probably haven’t heard much about this because really, let’s face it. Yeast? How interesting is that? It’s not something your grandmother might bring up at the dinner table. But let me put it this way: when it comes to brewing beer, yeast is like one of the Beatles (try to read on, Rolling Stones fans). The Fab Four of brewing are barley, water, hops and yeast. Sure, other members can be added to alter the style or taste of what is being produced (I’m talking to you, Yoko Ono), but the foundation of any beer recipe is made up of the Fab Four, and each one plays a unique role in creating the character of the beer you drink.
Yeast may not be the most glamourous of the Fab Four, but it is certainly one of the most crucial – this is the “booze” part of the beer equation. Yeast is a living, single-celled organism and it eats sugar. When added to the sweet liquid made with mashed barley and water, it metabolizes the sugars, producing alcohol, CO2 and small amounts of a few other chemicals as by-products that contribute to a beer’s flavour. There are hundreds of different strains of yeast stored in yeast banks around the world. These have been cultivated and domesticated for broad and reliable use by brewers. Each strain has a different talent, and the brewer selects each one depending upon the desired flavour profile they want to create.
For centuries, brewers didn’t really know what yeast was. Because yeast is everywhere (in the air, on plants, in the soil, on your skin), beer fermented spontaneously. “Wild” yeast, floating through the air, landed on the surface of an ancient monk’s fermentation vessel and soon the liquid would start to bubble. The monk would observe this “miracle”, get down on his knees and sing the words, “God is good”. Often, the yeast was transferred from batch to batch by placing a stick in the fermenting beer, then removing it and drying it out. The stick, now covered in dried yeast, would be tossed into the next batch of beer where the yeast would awaken and start the fermentation process all over again. For centuries, that stick was simply magical. It wasn’t until the mid-1800’s that Louis Pasteur (the French biologist renowned for “pasteurization”) actually conducted experiments that defined how yeast worked.
Fast forward to the Fall of 2017, and the budding biology students at Acadia University are in the midst of a yeast scavenger hunt. They’re isolating and collecting wild fermentative yeast samples from a variety of Nova Scotia surfaces. These include pumpkins, apple trees, the bark and leaves of maple and birch trees, blueberries, bay berries, and seaweed, to name just a few. The goal is simple - to harvest and cultivate “wild” yeast strains that can contribute exceptional regional flavour to Nova Scotia craft beers.
Some early trail-blazing in the use of locally harvested wild yeast has been done by Cape Breton’s local brewery, Big Spruce. However, as they discovered, not every strain of yeast harvested is rewarding. Often wild yeasts can produce strong flavours that can be off-putting, like the smell of wet goats or overly ripe fruit. But the best results offer a layered subtlety of complex flavours, from hints of hayloft and musty apples to ripe berries or black-pepper spice that offer a unique flavour-boost to the beer.
The term “terroir” is used to describe the sum total effect of a region’s climate, soil, moisture and geology on a wine or other locally grown product. The research efforts being done by Acadia and Saltbox are trying to harness the community of yeasts unique to Nova Scotia that lead to the proverbial unicorn in the woods – a newly identified microflora that contributes to the development of a phenomenal sipping sensation. In the spirit of collaboration, the resulting yeast(s) would be made available to all Nova Scotia craft brewers. Similar to the Nova Scotia wine industry’s unique “Tidal Bay” appellation, imagine an “only-in-Nova Scotia” crafted beer that truly reflects the products of the region – locally harvested grains, locally grown hops, locally sourced water and locally cultivated yeast. The Fab Four’s anticipated new release, “A Taste of Place - Truly Nova Scotia”.
Coming soon to a brewery near you!