Abstract
The combination of modified mashing method and arrested fermentation for the production of low-alcohol and non-alcohol beers was studied. Therefore, five regimes for fermentation of wort with reduced fermentable sugar content with top-fermenting yeast strain at low temperatures and pitching rates were investigated. According to the fermentation dynamic results the decrease in the fermentation temperature from 10 °C to 5 °C at pitching rate of 109 Colony Forming Units cm−3 ( CFU cm−3 ) led to significantly reduced concentrations of ethanol and secondary metabolites in beer. The temperature decrease from 10 °C to 7 °C at pitching rate of 107 CFU cm−3 resulted in a decrease in the alcohol concentration and increase in all the secondary metabolite concentrations except for the vicinal diketones concentration. Data show that yeast biomass does not grow at 5 °C and at inoculum concentration of 107 CFU cm−3, which makes fermentation impossible. Fermentation kinetics using Monod's model supplemented with product inhibition was also investigated. Up to 1.7 % of alcohol accumulates in the beer in some of the variants within 7 days. At low fermentation temperatures, yeast biomass utilizes part of the substrate to maintain its vital activity under stress fermentation conditions, which leads to a reduction in the amount of alcohol synthesized. The synthesis and reduction of the secondary metabolites was delayed compared to conventional beer fermentation. The sensory evaluation of the beers produced showed that the most appealing beer was the one produced at 10 °C and pitching rate of 109 CFU cm−3.
Highlights
There is a growing interest in the development of new assortments of beer with low-alcohol content
3.1 Fermentation at pitching rate of 109 CFU cm−3 3.1.1 Fermentation dynamics The first series of experiments were conducted at initial biomass concentration of 109 CFU cm−3, which was typical for traditional pale beer
An advantage of the low-alcohol fermentation is the low synthesis of carbonyl compounds, which leads to the reduction of the beer maturation time
Summary
There is a growing interest in the development of new assortments of beer with low-alcohol content. The main reasons for the start of low-alcohol beer production in the 20th century were: the lack of raw materials during the World Wars and the prohibition for manufacture, sale and consummation of alcohol in the United States. The expansion of the assortment of beers with low-alcohol content is motivated mainly by the following reasons: provision to beer consumers of alternative products during their activities or under conditions that are conflicting with alcohol consumption; or promoting beers in countries where alcohol consumption is forbidden due to religious reasons [1,2,3]. In the United States alcohol-free beer means that there is no alcohol present, while the upper limit of 0.5 % ABV corresponds to the so-called non-alcohol beer or "near-beer" [1]. There are two different main groups of methods for the production of beer with low-alcohol content: physical and biological.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
