Wild Fermentation: Everything You Need to Know About Chips
There is nothing cooler than coals – especially for retro-futurists who love great beer.
Kulship is a large but shallow container made of copper or stainless steel. Use it to cool beer wort and its spontaneous fermentation. Kulships have been used for several centuries, and the most famous example of this is the production of the Belgian lambic at such legendary breweries as Cantillon. As for the unusual word “kulship”, it comes from the Flemish koelschip.
With the introduction of new equipment for cooling and temperature control, such as heat exchangers and cone-shaped fermentation tanks, most brewers abandoned the use of coolers.
Nevertheless, over the past decade, thanks to American brewers, the cools got a new life: Allagash, New Glarus, Russian River, Jester King, Black Project, The Veil breweries and many others began to produce a variety of types of sour beer of spontaneous fermentation, similar to lambic.
Fermentation in Coolship: The Wild Party
The capsules differ in size and depth, but a typical capsule looks like this: a large rectangular shallow tank, which occupies almost the entire room and is open to environmental influences. This allows you to achieve several goals. A large surface area allows the liquid to cool quickly (most brewers leave it to cool overnight). At the same time, all the solid particles present in the wort settle to the bottom.
However, the most important thing for brewers who create sour beer in this way is that yeast and microflora get into the unopened container from the air, giving the beer a peculiar or sour taste as a result of fermentation. In other words, wild bacteria and yeast floating in the air jump into the pool and throw a party. What happens as a result depends on time, place and season – all this taken together makes up a unique beer terroir.
This process is called spontaneous fermentation, since not strictly defined yeast strains grown in the laboratory get into the drink, but completely random microorganisms.
All thanks to Cantillon
A few centuries ago, coils were the norm. In the Middle Ages, brewers used a tree trunk hollowed out in the form of a boat for the same purpose. Perhaps this is how the kulship got its name (from the English. Cool – cold, ship – ship – approx. Per.).
The most famous cooler is set at Brasserie Cantillon, the world-famous lambic brewery in Brussels. Cantillon has been producing beer in the lambic tradition since 1990.
To Brussels for Lambic: How the Cantillion Brewery Works
Inspired by the activities of Cantillon, American brewers are also beginning to master the creation of beer with the help of coals. To date, there are at least two dozen of these unusual containers in the United States.
Typically, capsules are placed indoors with windows or other openings through which air (and the microorganisms inside it) penetrate. But there are exceptions: for example, in 2016, the Arizona Wilderness Brewing brewery organized an event called #campcoolship, in which 15 brewers went to the mountains, taking with them a mobile cooler.
Kulships – a new trend in craft brewing
Impressed by a visit to Cantillon, in 2007, the owner of Allagash Brewing installed a cooler at his brewery. Beer from the very first batches still serves as the basis for the Coolship range, such as Coolship Resurgam, Coolship Red, Coolship Cerise and Coolship Balaton.
Dozens of breweries followed his example. In 2012, Russian River Brewing began using the coalspike to produce varieties such as Sonambic and Beatification. Jester King Brewery from Austin (Texas) and Side Project Brewing from St. Louis (Missouri) began using the cools in their breweries in 2013. New Glarus installed the cool in 2014.
The well-forgotten old: how craft brewers use cools
The Veil Brewing Brewing from Richmond (Virginia) opened in 2016 and got its name just thanks to the fermentation process in the cooler. Remember we talked about a yeast party? After a long party in a cooler, a film of organic substances forms on the surface of the wort. When co-founder and chief brewer Matt Terpy studied with the owner and brewer of Cantillon Jean Van Roy, he learned that winemakers called this film “veil” (in English – veil – approx. Per.).
As the popularity of this ancient method, as well as other similar technologies, such as solera, grows, new horizons open up for American wild ales.