Cantillon Classic Gueuze
In addition to the impressive number of draft beers, Brouwer's Café in Seattle has an even more impressive list of bottled beers. The exact number escapes me but they must have many hundreds of different beers and vintages of beers on their menu.
Here I've selected a Classic Gueuze, a 100% lambic beer, from Belgian brewery Cantillon - perhaps the purest and best known lambic brewery in the world.
Lambic is a unique Belgian beer style. Unlike regular beers, that are brewed with carefully cultivated strains of yeast, a Lambic is produced by spontaneous fermentation: It is exposed to the wild yeasts and bacteria that reside naturally in the brewery. Such beers are usually dry and vinous with a slightly sour aftertaste.