OnTap Magazine

STYLE GUIDE EARTH It’s been in use in Norwegian farmhouse breweries for centuries, but somehow the craft scene only recently found out about kveik. Rob Cass gives the lowdown on this fast-fermenting, sturdy yeast. T he story of beer is one of evolution; of brewers adapting to local conditions in terms of ingredients, temperatures and yeasts, taking in uence from other brewing cultures and integrating this into their own brewing procedures. It is a story of changing the conditions of their environment and adopting styles successful in other regions, all in the pursuit of more consistency and predictable quality, and seeking to appeal to the tastes of the drinker. is is an incremental approach, and therefore it is rare to encounter a massive disruptive force which challenges so much of what has become conventional wisdom. A rediscovered group of yeast cultures from Western Norway, collectively known as kveik, have done just that, and are turning the brewing world on its head. You might have heard the stories: extraordinarily high temperatures, astonishingly rapid fermentation times and despite all this, clean fermentation pro les. WHAT EXACTLY IS KVEIK? Kveik (more or less pronounced “kvike”) means yeast in a certain Norwegian dialect, although it is not commonly used outside of the traditional farmhouse breweries. at said it is only one of many words used for yeast in Norway, especially among these farmhouse brewers. It describes the mixed cultures of yeasts used by these breweries over many centuries. Over time these yeasts have been domesticated and selected to perform in a very particular manner. e farmhouse ales brewed in the region would typically have been brewed for celebrations and events and would need to ferment quickly and be ready to drink very soon after brewing. ey would be brewed in a very warm environment and would be drunk fresh. Beer was only brewed occasionally so the yeasts were stored for long periods of time between brewing. Yeasts were unwittingly selected over many generations to provide these performance characteristics. Kveik typically ferments very warm, ideally around 33–38°C, which is extremely high compared to most domesticated ale yeasts. Because of this high fermentation temperature, these yeasts are able to complete standard strength fermentations in one to three days. Amazingly, they do not produce the harsh higher alcohols at these temperatures, and ester and phenol production is relatively subdued. Most incredibly, the traditional method for harvesting and preserving yeasts between batches is to crop (remove) yeast during fermentation and air dry. is is traditionally done with a device called a kveik ring – a series of wooden blocks arranged in a ring to maximise surface area. is ring would be dragged through the krausen of fermenting beer and hung up to dry. To start a new fermentation, the ring would KVEIK! 62 | Summer 2019 | ontapmag.co.za