Craft brewers got a good pour last week when the state Department of Revenue implemented new regulations allowing tours to be sold at varying prices. It’s a big deal for the owners of Left Nut Brewing Co., Gainesville’s first and only brewery, which has started production and is set to begin hosting tours this summer at its facility in the Chicopee industrial area. The company has stripped the 19,000-square-foot building and invested about $2 million in renovations and equipment.