In 2008, Allagash Brewing Co. built one of the first commercial koelschip—or coolship, as it is known in America—in the country. In simple terms, a coolship is a large, shallow steel pan about a foot deep that is used to both cool down wort after it is brewed and to expose the resulting concoction to naturally occurring yeasts and bacteria that are in the air. This is a traditional method used in Belgium, and very few U.S. breweries have the expertise, time or money1 needed to work with one.2
The Allagash website gives a bit more background on its coolship use:
In the summer of 2008, we decided to build a coolship at our brewery. A coolship is a large shallow pan used to cool wort overnight using outside air temperature. During the cooling process, naturally occurring yeast from the air inoculates the wort. In the morning, the cooled wort is transferred into barrels where the fermentation process begins. The beer is then aged for an undetermined amount of time, until we deem it “ready”.
Over the years, Allagash has released six different beers that are produced using its coolship: Coolship Red (5.7 percent ABV), Coolship Resurgam (6 percent ABV), Coolship Cerise (8.1 percent ABV), Ghoulschip (6.9 percent ABV), Coolship Balaton (5.9 percent ABV) and Coolship Single Barrel One (8.1 percent ABV), the latter two of which were one-time only releases.
Originally released for the first time in 2011,3 Coolship Red is a 5.7 percent wild ale that is aged in oak wine barrels for over six months with 100 pounds of fresh raspberries from Maine in each barrel. The 2014 release was on April 23 at Allagash Brewing Co., where each 375ml bottle was sold for $15 with a two bottle limit per person.
Allagash Coolship Red pours a very cloudy ruby red, almost looking like there is mud inside the glass. There is carbonation evident in the glass and is quite spritzy when poured, but it disappears surprisingly fast, leaving no lacing at all to speak of. Aroma coming from the top of the glass is a combination of extremely sweet raspberries, lemon rinds, grass, oak and earth, with a bit of an herbal undertone.
From my first sip, I am amazed how little sweetness is present on the palate, especially considering the almost cloying sweetness that is present in the aroma. There is a puckering berry sourness up front, almost akin to eating a Warhead made out of real fruit, along with bitter tannins. Flavors of oak and grass are also noticeable at different points, and the beer features a very tart finish that also includes a vegetable vine flavor that lingers for quite a while. As mentioned above, there is very little carbonation evident, but it works quite well with this specific beer.