One of the best known craft brewers in Vermont has been bought by a Massachusetts company. Mass. Bay Brewing Company, which produces Harpoon IPA, has acquired Long Trail Brewing Company. The two CEOs announced Friday that Mass. Bay will continue to operate the Long Trail Riverside Pub in Bridgewater Corners and Otter Creek Brewing Pub and Beer Garden in Middlebury. The Harpoon Brewery in Windsor will also start brewing Long Trail, Otter Creek and Shed beers. As part of the deal Whistlepig Whiskey, based in Shoreham, will take over the Otter Creek and Shed Brewery in Middlebury.