Elaboración de cerveza artesanal con levadura silvestre y comparación de parámetros frente a levadura comercial

Abstract

In this study, microbiological techniques were proposed for isolating a pure culture of non-conventional yeasts present in sourdough, which is prepared with a mixture of flour and water and subsequently fermented under ambient conditions. Several culture media were prepared, initially employing peptone, sucrose, and dextrose. Among the evaluated media, sucrose proved to be the most efficient in terms of yeast growth. This yeast culture was used as the fermenting agent in the production of a batch of American pale ale craft beer. The resulting beer was analyzed through physicochemical tests including alcohol content, turbidity, specific gravity, density, and degrees Plato; and organoleptic characteristics such as flavor, color, bitterness, aroma, and foam—compared with a craft beer brewed using conventional brewer’s yeast (Saccharomyces cerevisiae). With the microbiological culture obtained, a batch of craft beer was successfully produced. Organoleptic analysis showed that the use of non-conventional yeasts resulted in acceptable sensory characteristics for aroma, color, and flavor. However, other sensory traits suggested that these yeasts did not enhance bitterness or foam formation. Moreover, physicochemical comparison revealed lower alcohol production, increased turbidity, and reduced utilization of fermentable sugars by the microorganisms, as evidenced by the small difference in °Plato between the start and end of fermentation.