The Impact of Dry Yeast Rehydrated in Different Plasma Treated Waters (PTWs) on Fermentation Process and Quality of Beer.

Yeast plays a key role in the production of alcoholic beverages. Effective fermentation requires appropriate conditions to ensure the production of high-quality beer. The paper discusses the effect of dry brewing yeast (Saccharomyces cerevisiae and Saccharomyces pastorianus) after rehydration with water exposed to low-temperature, low-pressure glow plasma (PTW) in the atmosphere of air (PTWAir) and nitrogen (PTWN) in the course of the fermentation process, the formation of volatile compounds and other quality parameters of the finished beer. The obtained results show that the lager yeast strain initiated the process of fermentation faster after rehydration in the presence of PTWAir compared to all of the other treatments. It was observed that PTWAir significantly changed the composition of volatile compounds in the finished beer, especially by increasing the number of terpenes, which are compounds that positively shape the aroma of beer. In the case of PTWN samples, lower alcohol content, real extract, apparent extract and amount of biomass were observed in all analyzed strains.

Rheological and Microbiological Characteristics of Hops and Hot Trub Particles Formed during Beer Production.

During the production of beer, and especially beer wort, the main wastes are spent grain and hot trub, i.e., the so-called "hot break." Combined with yeast after fermentation, they represent the most valuable wastes. Hot trub is also one of the most valuable by-products. Studies on the chemical composition of these sediments and their rheological properties as waste products will contribute to their effective disposal and even further use as valuable pharmaceutical and cosmetic raw materials. So far, hot trub has been studied for morphology and particle distribution depending on the raw material composition and beer wort extract. However, there are no preliminary studies on the rheological properties of hot trub and hops. In particular, no attention has yet been paid to the dependence of these properties on the hop variety or different protein sources used. The aim of this study was to examine the effect of different hopping methods on hot trub viscosity and beer wort physicochemical parameters. Additionally, the hop solutions were measured at different temperatures. A microbiological analysis of hop sediments was also performed to determine the post-process survival of selected microorganisms in these wastes. For manufacturers of pumps used in the brewing industry, the most convenient material is that of the lowest viscosity. Low viscosity hot trub can be removed at lower velocities, which reduces costs and simplifies washing and transport. The sediments also had similar equilibrium viscosity values at high shear rates.

Application of Water Treated with Low-Temperature Low-Pressure Glow Plasma for Quality Improvement of Barley and Malt.

The aim of this study is to determine the quality of water treated with low-temperature, low-pressure glow plasma, either in the air or under nitrogen, in order to obtain high-quality brewer's malt. To this end, plasma-treated spring water was used for barley grain soaking. In two-row spring barley grain, the procedure provided significantly higher water uptake capacity and grain sensitivity to water, as well as energy and germination capacity. The resulting malt showed improved moisture and 1000-grain mass. Furthermore, laboratory wort produced from the malt by the congress method did not differ statistically from a control sample in terms of filtration time, pH, turbidity, color, extract, free amino nitrogen compounds, and aromatic composition.

Low Lactic Acid-Producing Strain of Lachancea thermotolerans as a New Starter for Beer Production.

Growing consumer interest in new beer flavors is contributing to the application of innovative materials and non-Saccharomyces yeast in brewing. The goal of this study was to test the impact of the low lactic acid-producing Lachancea thermotolerans MN477031 strain on the process of fermenting beer wort, with two different concentrations of bitter compounds, and on the quality of the beer produced. Qualify factors were broadly analyzed, including ethanol content, apparent degree of fermentation, sugars, organic acids, free amino nitrogen, glycerol, volatile compounds, ions and so on. It was proven that the L. thermotolerans MN477031 strain demonstrated a high capacity for rapid initiation of wort fermentation, and a tolerance to hop-derived compounds. As a result, the alcohol content in beer from this method of production was approximately 20% lower, while the content of the real extract was significantly higher in comparison to commercial Safbrew T-58. This strain stands out from many strains of L. thermotolerans due to the low lactic acid production and only marginal influence on pH decrease compared to Saccharomyces cerevisiae. Therefore, the potential of MN477031 in the production of different types of beer (not only sour) is very high. The composition of volatile compounds in L. thermotolerans beer differs-not only in terms of the use of the strain, but also in hop variety.

The Impact of Phytases on the Release of Bioactive Inositols, the Profile of Inositol Phosphates, and the Release of Selected Minerals in the Technology of Buckwheat Beer Production.

A relatively high concentration of phytate in buckwheat malt, and the low activity of endogenous buckwheat phytases, both of which limit the effective use of substrates (starch, proteins, minerals) for fermentation and yeast metabolism, gives rise to the potential for application of phytases in beer production. This study aims at obtaining a 100% buckwheat wort with high bioactive cyclitols (myo-inositol and D-chiro-inositol) concentrations released by exogenous phytases and acid phosphatases. Two mashing programs were used in the study, i.e., (1) typical for basic raw materials, namely the well-established Congress method, and (2) optimized for phytase activity. The results indicated a nearly 50% increase in the level of bioactive myo-inositol and an 80% degradation of phytate in the wort as a result of simultaneous application of phytase and phosphatase enzymes in the mashing of buckwheat malt. In addition, high D-chiro-inositol concentrations were released from malt to the buckwheat wort. The concerted action of the two phytases significantly increased (19-44%) Zn2+ concentrations in wort. This may be of great importance during mash fermentation by Saccharomyces cerevisiae yeasts. There is a potential to develop technology for buckwheat beer production, which, in addition to being free from gluten, comprises high levels of bioactive myo- and D-chiro-inositols.