You may have heard it said before – hops, malts, water and yeast are the four ingredients that are the foundation of nearly every beer. Within these ingredients there are endless variations which mean that the possibilities in brewing are infinite. It is this constant ability to experiment and refine that is central to how and why we brew.
Our head brewer Will Hartley is a fan of the adage "Brewers make wort but yeast makes beer." Recently we have been exploring the yeast varieties we use to make our beer. Until now, all our beers have been fermented using Saccharomyces yeast. There is huge variation between the individual strains of this species: think of our clean, crisp lager in contrast to the banana and clove esters from our White Wheat Beer – both are flavours determined by the yeast strain. Brewers have cultivated yeast strains over decades so that they are predictable in their fermentation and flavour profile. The beer writer Michael Jackson used the analogy of a dog to describe Saccharomyces – it’s trainable, reliable and mostly predictable.
Brettanomyces (Brett) is a yeast genus often found on fruit skins in the wild, and certain varieties are suited to fermenting beers. It behaves very differently to Saccharomyces. Two identical worts inoculated with Brettanomyces at different times and in different ways can create two completely different beers. The writer Jackson furthers his analogy: ‘if Saccharomyces is a dog, Brett is like a cat’. It is less predictable and it does its own thing. However, if you respect it and suggest rather than dictate what it does in your fermentation it can be rewarding.
Brett was first studied as a spoilage yeast by winemakers and brewers; without appropriate hygienic practices it’s easy for Brett to get into tanks and bottling lines, as it is common in the atmosphere. Its unpredictable nature and unusual flavour profile was, and still is, considered undesirable in some conventional processes. In his speech at the Carnival Brettanomyces in Amsterdam last year, Richard Preiss of Escarpment labs told us of the days where wine brands would have stickers saying ‘No Brett Here’ on their bottles.
Much like its well behaved counterpart, Brett has many strains and the flavours created by each vary widely. Brettanomyces has a less palatable sounding array of flavours associated with its fermentations and some strains are associated with ‘horse blanket’ or farmyard flavours, plasters, sweaty mangoes, smokiness or spiciness. As a result, this yeast can challenge many drinkers’ idea of what beer should taste like.
But when it works it really works. Brett in the right balance can provide depth of flavour, texture and aroma and really bring a beer to life. It can create tropical fruits, florality, minerals, sour cherries or a satisfying earthiness. It can provide such complexity that not only do bottles in the cellar evolve over time, but the beer changes from sip to sip, drawing you in as a drinker and constantly making you rethink. It’s an addictive pursuit and those flavours that at first seem alien become captivating.
Many Belgian beers gain their true colours from Brettanomyces. But Brett has a pivotal role in British brewing history and has been a defining characteristic of a lot of our classic styles: Porters, Old Ales, Stock Ales, Imperial Stouts and perhaps even India Pale Ales. The yeast has been driven out of British beer, but is something that we are keen to explore, highlight and bring back.
For many of these beers the character came from secondary, longer term fermentations with Brett, where more ‘funky’ flavours arise – something we are exploring with our barrel aging programme. Ready for release now is a beer that uses Brett in the primary fermentation in place of Saccharomyces. When used in primary fermentation, Brettanomyces can produce bold, vivid fruit flavours and aromas. The strain chosen has been cultivated by our yeast laboratory and identified as bringing strong tropical fruit flavours, minerality and only the tiniest hint of horse!
These characteristics make the yeast a perfect pairing for the hop flavours we wanted to showcase for our first Brett beer, ‘Taking Stock’. It’s a 6.7% India Pale Ale with orange and peach notes that come from a combination of the Brett strain that brings tropical fruit complexity, and lots of Simcoe that was used in dry-hopping. This both brightens and adds depth to the flavour profile. The pairing of Simcoe and Brett also provides hints of spice, which accents and enhances the fruity character, while providing balance to the higher-ABV mouthfeel and dry finish.
Taking Stock Brett IPA is available in keg, and will be pouring at our brewery tap room this Saturday 17th March.
