I recently purchased a pack of Philly Sour yeast from Lallemand brewing and wanted to give it a test run in a batch of homebrew. If you aren't familiar with Philly Sour, the Lallemand website gives the following description: Philly Sour produces moderate amounts of lactic acid in addition to ethanol in one simple fermentation step. . With high attenuation, high flocculation and good head retention, WildBrew™ Philly Sour is an ideal yeast for traditional styles such as Berliner Weiss, Gose,