As used in this subchapter, “small farm winery” means a wine-making establishment that sells no more than two hundred fifty thousand gallons (250,000 gals.) of wine, the alcoholic content of which does not exceed twenty-one percent (21%) annually as reported on the federal tax report form TTB F 5120-17, as it existed on January 1, 2007. For the purposes of this subchapter, a winery or a group of wineries consisting of at least fifty percent (50%) common ownership is to be considered one (1) small farm winery.