The South Slope's vibrant craft brewery scene will soon have a new reason to celebrate: the first-ever "Sour Fest" on Saturday, July 20, from 1 p.m. to 6 p.m. Organized by the South Slope Brewery Association, the event aims to showcase the unique and often challenging brewing process behind sour beers, and to highlight the collaborative spirit of the neighborhood's breweries. The festival will feature exclusive sour beer offerings from participating breweries, including Burial Beer Co., Wicked W