Batch 44 / Dubbel is our eighth bottled beer, and we thought it was time to give you an inside look at how our beers go from brewhouse to bottle.
Bottling any beer is a tricky process. Believe it or not, beer is fairly delicate, and the packaging process exposes beer to air and light, both of which can affect flavors. As anyone who has visited the tasting room likely noticed, we are not a big brewery, so our bottling process has more in common with techniques that homebrewers will recognize.
We start by wheeling our trusty fermenters into the cold room to drop the temperature of the beer, halting fermentation and allowing the yeast and sediment to settle to the bottom to be filtered out. Then it’s pumped from fermenter to tank, where we add a mix of sugar and fresh yeast, and then pumped from tank to the bottling machine.
Instead of a huge, Laverne and Shirley-esque bottling line, we have a semi-automatic filler originally intended for wine. Our 750mL bottles get rinsed with sanitizer and flushed with carbon dioxide, then they’re ready to fill. We pop a bottle over each spigot and beer flows from the tank, thanks to the magic of gravity. Finally, we use a pneumatic machine to cap the bottle and--voila!--the beer is packaged.
Bottling isn’t the end of the process. If you were to immediately open one of these fresh bottles, you’d find a beer that is flat and unfinished. This is because all of our beers are bottle conditioned. Remember the yeast and sugar we added? Now it’s time for them to get to work.
The fresh brettanomyces will devour the added sugar, plus any residual sugar left over in the beer. Sugar is broken down into alcohol and carbon dioxide, and since the carbon dioxide can’t escape the capped bottle it dissolves in the beer, carbonating it. It takes a couple weeks for carbonation to reach the right levels, so we’ll store bottles for two to four weeks before deciding they’re ready for the world.
Thanks to the active yeast, bottle conditioned beers are ideal for aging. If stored at cellar temperature--around 50 degrees Fahrenheit--the yeast will continue fermenting, consuming any residual sugars to create a drier beer than the one that was initially bottled. Flavors will also change slightly. Hoppiness will fade, alcohol heat will mellow out, and the combination of re-fermentation and slight oxidation can add wine and sherry-like flavors. Because of the additional time needed for bottle conditioning and ideal aging conditions, we tend to choose barrel aged or funkier brews for bottling over hoppy and lighter brews, which are best when fresh and don’t mature as gracefully.
Still curious about our process? Come visit our tasting room and we're happy to talk shop!
Dan and Peter