Basic Brewing Radio recently did an interview with one of the brewers at Allagash Brewing Company about spontaneously fermented beer. You can see the video below that started the whole conversation. I think it is pretty cool and an awesome experiment for a production brewery.
Allagash Brewing Company in Portland, Maine has built a cool ship for spontaneously fermenting beer. This is a traditional method for brewign in Belgium. This is the inaugural use of the cool ship. You can see that the beer is coming from inside the brewery. At this point it has just been filtered in our whirlpool. the beer passes through the sieve so that there are no pieces of spice or hops in the cool ship. The beer will sit in the cool ship overnight, allowing the beer to cool. When the temperature is right ambient yeast will begin to ferment the beer, in this way it is spontaneously fermented.