WildBrew Philly Sour™ – Single-Step Yeast for Lactic Acid & Ethanol Production in Sour Beers (10 g | 0.35 oz) Create crisp, sessionable sour beers in one fermentation step. WildBrew Philly Sour™ is a unique Lachancea yeast that produces both ethanol and lactic acid, eliminating the need for bacteria or kettle souring. It’s the ideal yeast for brewers seeking a clean, fruity, and refreshing acidity. Naturally Tart. Stone-Fruity. Easy Sour Fermentation Without the Bacteria. Ferment innovative sour styles with red apple, peach, and stone fruit notes—no extra steps needed. Selected by the University of the Sciences in Philadelphia (patent pending), this high-flocculation yeast delivers reliable attenuation, strong head retention, and resistance to hops—making it perfect for Berliner Weisse, Gose, American Wild Ales, and Sour IPAs.