Production of non- and low alcohol beers with maltose-negative yeasts and alternative cereals

Sales of non- and low alcohol beers (NABLAB) are increasing year after year. However, there are still some important sensory deficiencies in these beers, which are brewed with commercially available NABLAB yeasts.
The NABLAB project investigates how these shortcomings can be avoided or improved. To this end, alternative grains are incorporated into the brewing process. Specifically, the cereals spelt, rye and oats (raw and malted form), and einkorn wheat and khorasan (only raw form) are incorporated. In addition, we investigate how the traditional brewing process can be adapted to suit this style of beer.
The overall objective is to provide knowledge to the brewers and to offer a detailed practical guide on how to develop a qualitative, distinctive NABLAB that can be seen as a true alternative to normal beer. This offers brewers the opportunity to take their place in this strongly growing market segment without large investments and risks.

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.