NABLAB: Production of non- and low-alcohol beers with non-Saccharomyces yeasts and alternative cereals (NABLAB)

In response to the increasing consumer demand for more diversity in high-quality non- and low-alcohol beers, this project explores the potential of combining non-Saccharomyces yeasts with alternative raw materials. To achieve this, commercially available alternative yeasts are compared to one another. Moreover, it is investigated which raw materials are most suitable to combine with these yeasts, which brewing and fermentation parameters to use, which flavour profile is obtained and what the stability of these innovative beers is. The overall goal is to provide the brewer with knowledge with which a qualitative, characteristic non- or low-alcohol beer can be developed. 

During this project, it was revealed that a lack of know-how, excessively high investment costs for physical dealcoholisation methods, and sensory deficiencies in the final products were hindering brewers from entering the rising non- and low-alcohol beer (NABLAB) market segment. To enrich brewers' knowledge on NABLAB production through an alternative, and cheaper biological method that limits alcohol production during fermentation, 10 commercially available non-conventional yeasts were collected. Using these maltose/maltotriose-negative yeasts, test beers (100% barley malt; 6.5°P) were produced, after adjustment of the wort production in order to form less fermentable sugars (to reduce sweetness and alcohol content) and more dextrins. For maltose-negative yeasts, mashing was done at 72°C, and for maltotriose-negative yeasts at 82°C, to produce non-alcoholic beers (<0.5% ABV) and low-alcohol beers (<1.2% ABV), respectively. These test beers were chemical-analytically, microbiologically, and sensorially characterised. It was found that maltose-negative yeasts consume little Free Amino Nitrogen (FAN) and cause only a limited pH drop during fermentation. The alternative yeasts showed significant differences in overall flavour, but through sensory and chemical-analytical characterisation of the produced test beers, brewers can now estimate what to expect from these yeasts and make an informed choice depending on the desired flavour profile/beer style. Saccharomyces cerevisiae var. chevalieri, Torulaspora delbrueckii, and Pichia kluyveri were selected as the most promising yeasts. Furthermore, 14 alternative raw materials (40% addition) were incorporated into the wort production through modified mashing schemes. The four selected yeasts were combined with resp. 40% rye malt, oat flakes, buckwheat, einkorn, and khorasan, to explore how these alternative cereals/malts could contribute to the further improvement and diversification of NABLAB. It was revealed that, through the choice of the raw materials, some very innovative and high-quality NABLAB can be produced, showing enhanced fullness, improved foam stability, turbidity, colour, dissolved protein content, lower alcohol content, and even reduced wort flavour. The successful implementation of these alternative cereals/malts and yeasts on a pilot and industrial scale validated the laboratory-scale results.