Three Maine breweries are doing what, a mere decade ago, conventional brewers’ wisdom said was impossible: making spontaneously fermented beer outside the climes of Belgium’s Senne River Valley. Hot, unfermented beer gets pumped into a shallow, open, vat called a coolship — basically a giant brownie pan. A pastiche of wild, airborn yeasts settles in and starts turning sugars into alcohol. After the brew ages a couple of years, you’ve got sour, barnyard-y, totally delicious beer. Allagash was first to execute the process outside Belgium; now, Oxbow and Rising Tide (and only a handful of other U.S. breweries) have followed suit. Maine’s coolship beers come in all different forms: aged with raspberries or cherries, rested in blueberry wine barrels — or straight-up, the purest way to experience the funk.