Gen and Jonny Mills of Mills Brewing like their beer wild. They set out to produce beer with “minimal modern intervention” using spontaneous fermentation and experimenting with wild yeasts, which they cultivate themselves.
They were unsure if the British beer drinking public would be just as passionate, but they have been leading the way and the craft drinkers are catching up with them. Based in Berkeley, near Bristol, in the county of Gloucestershire, their shared passion led them to live in a caravan outside their brewery, a re-converted barn.
“Our raison d’être is to produce beers using 100% wild cultures sourced from nature. No brewers yeast, no lab cultivated wild strains. A true expression of our locality,” they write in a blog post on their site.
All of their beers are fermented and matured in wooden barrels. The only stainless steel is their blending tank and open wort cooler, or coolship, used to naturally inoculate their spontaneously fermented beer in the “spirit of Belgian lambic blenders” they say.
They started what was to become their first commercial release in autumn 2015, a beer/cider hybrid collaboration. They fermented wort for eight months in old cider barrels with the residual lees from a previous cider fermentation. From this and it was from this they took their inspiration for the production method for Running Beer.
Running Beer is made with rye, oats, barley and wheat. The wort is boiled for three hours with aged hops and finished with a new English variety Olicana. The result is fermented with their house mixed culture in bourbon and wine barrels for around six months.
A typical brewing year includes their second keg release of Running Beer in October 2017. This was a blend of beers from several barrels which were fermented using locally sourced house culture, for six to eight months, according to a post in May 2018 on their site. They subsequently released two beers fermented with wild cider lees in individual barrels from a single wort.
“The first release was Saison Lees,” they reported. “This single barrel fermentation had produced farmhouse ale characteristics which were complemented by dry hopping with our one of our favourite European varieties. It was released after a month in bottle to showcase the fresh hops, but has evolved dramatically in bottle and now has some assertive Brettanomyces funk.”
“The second barrel was initially more challenging, showing aromas vaguely reminiscent of sour milk. Despite that, it maintained an odd allure and we decided to allow 6 months of conditioning in bottle before release. The beer was lighter and more subtle than its sister beer, so was christened Spectre Sister.”
They made a splash at BXL BeerFest in 2018 and were invited back for this year’s festival, where they showcased their fourth blend of Running beer, Mills Today (their first spontaneously fermented beer), Mills Dirt (a blend) and Mills Draw Together (a blend of three barrel fermented beers).
Beer Idiots at the BXL BeerFest 2019Jef Pirens of Brouwerij D’Oude Maalderij