Sour beers have long been a part of the brewing tradition. Indeed before the advent of refrigeration and advances in the science of fermentation in the mid-nineteenth century, almost all beer was, to varying degrees, sour. The sour comes from lactic acid bacteria during the fermentation process, with further complexity from strains of 'wild' yeast.
Brewing today is often romanticised by highly paid marketeers, they tell you that beer is a natural artisan product, but more often than not it is a very industrial process with highly automated machines and button pushers doing the work. The romance and the art of brewing come through in a very different way when using the extraordinary uncontrollable wild yeasts and bacteria.
Instead of, as in traditional ale making, fermenting solely with sacchromyces yeast we could also add our strains of bacteria and put the beer into oak casks to mature and sour. Bacteria gobble up sugars in the beer and convert them into acids, like the ones in Granny Smith apples and lemons. The microcritters also churn out a smorgasbord of flavours and aromas. The result is a brew that has all the complexity of a fine wine and a delicious sour zing. We are embracing the time-honoured Belgian art of deliberately infecting beer with the same “wild” bugs that generations of our predecessors so painstakingly eradicated. The result: pleasingly sour, food-friendly beer, mysteriously complex and engaging.
There's wild yeast and bacteria everywhere, especially here in Somerset with so many orchards nearby, when you make a happy home for them in your brewery they just show up and spontaneously ferment — and sour — a beer. We have painstakingly experimented with locally occurring natural yeasts from the air and on local wild fruit to be able to develop our own strain of "wild" yeast to use in a number of our sour beers in the future. Another of our experiments has been around the use of the Hobbs House Bakery sourdough culture, the beer 'Sourdough' is a homage to the historical relationship between beer and bread.