Over the course of 3 months, Perpetum naturally becomes tart and full of character. A unique solera method, created using a proprietary yeast blend, ensures consistency and perpetual motion. Inspired by traditional Berliner Weisse style ales from northern Germany, refermentation with strawberries and rhubarb brings spirited balance to our bright and lively house sour wheat ale. No kettles were soured in the making of this beer.