Optimisation of quality features of new wheat beers fermented through sequential inoculation of non-Saccharomyces and Saccharomyces yeasts

The choice of the starchy ingredients as well as that of the yeasts strongly can represent a useful tool to differentiate the final beers. Our research investigated twelve white beers obtained applying a 2-factor mixed 3-level/4-level experimental design. The first factor was the cereal mixture, with 3 combinations of barley malt (65 %) and unmalted wheat (35 % of common, durum, or emmer). The second factor was the yeast used to carry out the fermentation trials, i.e.: a S. cerevisiae starter strain (WB06); an oenological S. cerevisiae strain (9502); two mixed starters made of an oenological Schizosaccharomyces pombe strain (6956) and, alternatively, one of the two S. cerevisiae strains. Most beer attributes were significantly (p 0.8) by the fitted models. [Display omitted] •3 wheat species (common, durum, emmer) were used as a starchy ingredient.•2 S. cerevisiae alone or in sequential fermentation after Schizosaccharomyces pombe.•Optimisation was performed by applying a 2 Factors mixed 3-level and 4-level design.•Most beer attributes were mainly influenced by the ‘wheat species’ factor.•Beers fermented by S. cerevisiae strains alone had the best overall sensory quality score.