Beginning April 20, breweries in Portland will have to pay a $500 fee to operate a tasting room in Maine’s largest city – the epicenter of the state’s craft beer scene. The Portland City Council approved the new license requirement by a unanimous vote Monday as a way to level the regulatory playing field with traditional bars, which pay thousands of dollars in licensing fees to serve a variety of alcohol and food. Tasting rooms have burst onto the scene since a state law was changed in 2011 to allow brewers to sell samples of the beer they make.