New Belgium's wood program is pretty amazing. The importance of wood in the care and nurturing of wild yeasts is critical, and a feature that distinguishes certain beer styles. As beer ages in wood, oxygen enters the slightly porous container and feeds a chemical process where alcohols are converted to acids and esters (among other, sometimes less savory, compounds). You can't make lambic or the Flanders style characterized by Rodenbach without wood. Indeed, it's not easy to make some of these beers in anything less than very large wooden tuns (foeder in Dutch, foudre in French) because the flow of oxygen has to be just right. In large vessels, where the surface area is low (far lower than in wine barrels) and the oak staves thick, the oxygen just worms its way in molecule by molecule.
|New Belgium's foeders. Photo by Todd Gillman.|
Over the course of the past decade plus, New Belgium has quietly been picking up massive foeders ranging in size from 60 hectoliters to over 200--with a preponderance at 130. They've managed to score them the same way the Belgians did--by scooping up cast-offs from wineries. There's a pleasing quality of symbiosis in the arrangement, because after a certain number of years the wine will no longer pick up oak tannins--which is exactly what wild-beer breweries want. After the wood character is gone, they're perfect for lambic and tart Flanders ales. Amazingly, these old tuns will last decades; Rodenbach still has three that date back to the 1830s.
Apparently now there's a bit of a run on them in the American market as other breweries try to score their own--but New Belgium has already gathered quite a trove. After the a new set of foeders arrive, they'll have 3200 hectoliters of capacity--a massive quantity compared to other breweries, but just a drop compared to the brewery's total capacity.
New Belgium makes two beers to put in the foeders, Oscar, a dark ale with a grist very similar to 1554 lager (14-15 Plato) and Felix--get it?--a slightly stronger (17 Plato), light-colored ale. Listening to Lauren talk, I heard this familiar echo that came all the way from Roeselare. New Belgium's process isn't exactly like Rodenbach's, but the fidelity to wood-aging and acidification sounded so much like what Rudi Ghequire told me. This isn't too shocking; New Belgium's Peter Bouckaert came to Fort Collins from Rodenbach in 1996. The program that would result in La Folie--really the only example of a credible commercial Flanders red/brown I know outside Belgium--began a year after he arrived.
In Rodenbach's process, the foeders are filled and left to ripen for roughly two years. Batches of old beer are blended together to form a "mother blend" which is then blended back with young beer. New Belgium does something more along the lines of a solera project. Lauren, who is the principle blender, samples beer from each foeder and takes notes on what she finds. She then creates a master blend of different proportions of each foeder--30 hl from Foeder 1, 60 from #2, 70 from #3 and so on--leaving the foeders partly full. Eric replenishes them with fresh beer and they let them ripen further until its time to make a new batch. So each foeder may have a more aged or younger character, depending on when it was last replenished and by how much.
Incidentally, Peter used tons of different bugs in the original inoculation, including strains of pediococcus, lactobacillus, and brettanomcyes. This is similar to Rodenbach as well, but the proportion of brett is a lot higher at New Belgium. (Another funny parallel. Rodenbach used to supply all the area breweries with their yeast, a practice they finally curtailed when Palm bought them in 1998. New Belgium did, too, until other breweries started gathering accolades for the beer made with their yeast.) I can imagine style Nazis complaining that La Folie is too funky with brett to be considered authentic. Hogwash. This is the beer New Belgium wants to make, and the brewers and blenders relish the brett character. (American in general seem more tolerant of brett than Belgians.)
The last thing we did at the symposium was try a blend of our own beer. New Belgium had racked off four firkins from Foeders 2, 7, 8, and 14. We all got samples of each and did our best effort to mix up a master blend. La folie ("the madness") indeed. It's a whole different post, but I'll say this: blending is hard. I would say that the skill of a good blender is an order of magnitude rarer than the skill of a good brewer. (Let's not even speak of bloggers.) You have to have an exceptional palate and a talent for understanding how the flat, warmish beer you're swirling together will taste when its carbonated and chilled. I once watched Ron Gansberg begin the blending process for his sublime Apricot Ale, and what he came up with tasted kind of raw and harsh to me. Somehow Ron could understand the language that beer was speaking and knew what that blend would ultimately taste like. It was probably Flemish.
A great time, and one I'd encourage you to experience if you ever have the chance. Most beer events are high on the sensual aspects but low on educational ones. This was high-fiber larnin. We could use more of them.