Thornbridge and Brooklyn collaborate on Serpent
Thornbridge and Brooklyn, together with their friends at Oliver’s Cider and Perry, are releasing a rather special new style of beer. Serpent is a 10% Belgian-style beer that was brewed at Thornbridge and then re-fermented in Bourbon barrels, with lees from cider and perry fermentations, over a period of over 18 months.
As Garrett Oliver, Brooklyn Brewery’s brewmaster, explains: “The idea came to me over two years ago while producing the ‘Ghost Bottle’ series. We had used wild lees from natural wines to produce some of these beers, and I wanted to build on this by using lees from cider making. Thornbridge, as one of my best friends in brewing and one that is technically adept, were my obvious choice as a partner.”
Rob Lovatt, head brewer at Thornbridge, was delighted to get involved: “Working with Garrett is always an adventure, and it came at a time when, while we had some amazing results with beers such as whisky barrel aged stouts and Flemish Brown-style beer, we wanted to break new ground with our barrel ageing. Not only in terms of scale, but also in terms of the challenges maturing and fermenting beer in barrels presents.”
One of the challenges that Brooklyn and Thornbridge had to overcome was the choice of lees – the muddy sediment produced during fermentation of cider which contains a myriad of wild yeasts and bacteria. Garrett Oliver takes up the story: “In November of 2013, Rob and I, along with other brewers from both Brooklyn and Thornbridge, went to visit Tom Oliver, one of the world’s most respected and revered cider and perry makers, down in Herefordshire. After watching the maceration process and a tour of the fermentation rooms, where nature is allowed to do its thing and no sulphur is added to the tanks or barrels, we had an extended tasting and explained to Tom about the project. Tom was soon on board and agreed to send us all of his lees from the 2013 season.”
Gradually, Thornbridge started to receive polypins of wild lees from Herefordshire, each one labelled with the specific fermentation from which it had come. During this time, Thornbridge also received a huge delivery of 120 fresh Bourbon casks, sourced by Brooklyn brewery directly from the Four Roses Bourbon distillery in Kentucky. The project was now in full swing.
With the components for the maturation and re-fermentation stages now in place, Rob and his team began to brew the base beer, a Belgian-style Golden Ale. Rob explains: “We were confident with the brewing and primary fermentation, but we were all aware that the maturation phase could go seriously wrong and with 120 barrels in total, that would be a big loss, so we needed to give real attention to detail to the entire process. The lees contained an unbelievable diversity of microflora that continued to metabolise the sugars still present in the base beer. Getting the temperature right and constant checks of every barrel was a top priority, to ensure the beer was in the right condition to let all the wild yeasts and bacteria work their magic. It’s taken nearly 18 months of lab analyses, tastings and most importantly patience before we got to the bottling stage.”
Garrett Oliver flew over to help decide upon the final blend and assist with the bottling process, where a full bottling conditioning with Champagne yeast was decided upon. Thornbridge, busy in the run up to Christmas, were forced to draft in an additional seven staff, recruited from an advert placed in local craft beer stores. The last bottles, corked and caged, finally rolled off the makeshift production line after 3 weeks of solid blending and bottling, thus completing a project that had begun almost exactly two years previously.
Both teams at Brooklyn and Thornbridge are absolutely delighted with the final beer. Garrett says it has demonstrated that: “Through natural lees, it is possible to take the fermentative “terroir” of a piece of countryside and concentrate it into a relatively small amount of liquid, and then have that terroir proliferate through a beer. It’s connecting beer back to the land. If someone didn’t tell you that Serpent was a beer, you might at first think that it was a cider, or perhaps an Arbois wine. The apple-like aromatics are apparent, along with a hint of oak, expansive fruit and a long bone-dry finish. It is a truly culinary drink and one that will pair very nicely with pork dishes, game meats and cheeses.”
“We’re really captivated with it“, says Rob, “and it was well worth the sleepless nights we had worrying about the process. The final beer is completely unique, and seems to exist somewhere between cider, beer and wild ales such as American-style sours or lambic. We like to think the alliance between Brooklyn and Thornbridge has created something genuinely ground breaking, but most importantly, produced a great beer to drink.”
Perhaps Garrett sums up the experience best: “The Serpent Project captured the very essence of collaboration brewing – this is about a beer that neither we nor Thornbridge could have made without each other.”