Wort Quality Research Articles

Metabolic profiling of wort fermented with water kefir grains and its effect on wort quality

Wort, derived from malt saccharification, contains a myriad of vital nutrients, such as polyphenols, flavonoids, and sugars. Beer, a time-honored libation originating from malt fermentation, graces the palate with its rich flavor and purported health benefits. Unfortunately, due to its high alcohol content, consuming beer is considered inappropriate for pregnant women and children. Hence, there is a need to develop a low-alcohol or alcohol-free fermented beverage derived from wort. This research utilized water kefir grains to produce a low-alcohol fermented beverage from wort and examined the effects of water kefir grains fermentation on various attributes of the wort, including physicochemical properties, organic acid composition, sensory characteristics, volatile compounds, and microbial diversity. Remarkably, after fermentation, a new type of low-alcohol or alcohol-free wort beverage is produced. Moreover, the fermentation process generated numerous volatile components that enhanced the sensory profile of the beverage. The findings presented in this study serve as a valuable guide for the development of innovative low-alcohol or non-alcohol fermented beverages from wort.

Barley varieties registered in the Slovak Republic after the harvest of 2023

After the harvest 2023, three varieties were registered in the Slovak Republic after three years of testing: the spring barley variety LG Rhapsody, the two-row winter barley variety Claudia, and the six-row winter barley variety MH Irén. The malting quality was determined for the varieties LG Rhapsody and Claudia. LG Rhapsody gave extract in malt dry matter of 83.2%. Proteolytic modification of this variety was high (Kolbach index 52.3%). The diastatic power (343 WK), the quality of the sweet wort (apparent final attenuation 82.1%), and the cytolytic modification (friability 94% and β-glucan content 60 mg/l) were at an optimal level. In all cases, the variety gave a clear sweet wort. The winter two-row barley variety Claudia gave a sweet wort with an extract of 81.5%. Kolbach index (46.2%) and diastatic power (508 WK) were at optimal levels. The quality of the sweet wort (apparent final attenuation 80.5%) and the cytolytic modification (friability 83% and β-glucan content of the wort 169 mg/l) were at an average level.

Effect of Mashing-in pH on the Biochemical Composition and Staling Properties of the Sweet Wort

Mashing is a decisive brewing step, affecting wort quality. Critical mashing parameters include time, temperature, pH, mash density and oxygen uptake. While the pH-dependent biochemical changes during mashing have been researched, the oxidative processes remain unclear. This work explores the impact of pH conditions during mashing on the biochemical composition and oxidative properties of wort. In laboratory trials, mashing was conducted at different mashing-in pH (4.5, 5.0, 5.2, 5.4, 6.0). The sweet worts were analyzed for extract, fermentable sugars, limit dextrins, amino acids, soluble proteins, polyphenols, color, aldehydes, transition metals, reducing potential, and rate of radical formation. Differences were found in enzymatic activities (particularly proteolysis), color, aldehydes, transition metal ions, the rate of radical formation and the rate of oxygen consumption. Notably, when adjusting the pH at mashing-in, the obtained wort tends to gravitate toward the pH of the unadjusted wort, underscoring its buffering capacity. This was reflected by similar properties of the produced worts, indicating pH playing a lesser role during mashing compared to time/temperature. However, under extreme acidified conditions (pH 4.5 at mashing-in), the produced wort markedly deviates. An intriguing negative correlation between the reducing potential and the content of transition metal ions with the rate of radical formation is discussed.

The effect of hydrodynamic cavitation on isomerization of hop alpha-acids, wort quality and energy consumption during wort boiling

Wort boiling is one of the most energy-intensive steps in beer production because the isomerization of hop alpha-acids (AA) into iso-alpha-acids (IAA) is a time and energy-consuming process. Acceleration of this process by hydrodynamic cavitation (HC), created by a Venturi tube cavitation nozzle, at temperatures below the boiling point, has been tested on a pilot scale. The results show that HC accelerated AA isomerization at all temperatures tested (70–90 °C). The highest HC powered isomerization yield was achieved at 90 °C. However, some quality parameters of the wort were not satisfactory (dimethyl sulphide content, hot break) and therefore the process was extended by a final short boil (10 min). This led to a wort comparable to that obtained after the traditional boiling process (100 °C, 90 min) with a simultaneous 33% energy savings.

Use of unmalted cereals with enzyme preparations in brewing

The use of unmalted grain is one of the methods for improving quality, reducing production costs, and creating new types of beer. However, the enzymatic activity of such raw materials is zero, so the use of enzyme preparations is relevant. The purpose of the study was to compare the quality indicators of 100% malt beer and beer with the replacement of malt with unmalted barley using enzymes. Methods of technical and chemical analysis were used to determine the organoleptic and physico-chemical parameters of beer. Recommendations have been developed for intensifying the preparation of wort using various types of grain raw materials – unmalted barley and rice grits with the addition of enzyme preparations from Novozymes (Denmark) at different stages of brewing were developed. When testing new enzyme preparations (β-glucanase complex, xylanase), the filtration time, wort viscosity, and the content of β-glucans and arabinoxylans decreased by about 20% compared to the control samples. The use of a new enzyme preparation resulted in better breakdown of substances, which affected the quality and duration of filtration. This leads to an improvement of wort quality, reducing the duration of the process and reducing the cost of raw materials. To ensure the required ratio of substances in the wort, it is necessary to introduce complex enzyme preparations – peptidhydrolase, α-amylase, endo-β-glucanase (Ceremis Plus). Preparations containing endo-β-glucanase (Ultraflo Max) should be used at the beginning of mashing to improve the rheological properties of the wort and reduce its viscosity, which improves the filtration process. To obtain beer with the required degree of fermentation during mashing, it is better to use new enzyme preparations (glucoamylase). The practical significance of the study lies in the use of large amounts of unmalted grain together with exoenzymes such as Ultraflo Max and Ceremis Plus, which will allow brewers to produce wort and beer of the same composition and quality as premium wort and beer, using only malt

Effects of crushing and enzyme treatment on physicochemical, fermentation performance, and antioxidant properties of qingke (hull-less barley) wort

Crushing and enzyme treatment are pivotal factors that cannot be ignored in the mashing stage of qingke (hull-less barley) craft beer brewing. This study aimed to explore the impact of different mashing conditions on physicochemical, fermentation, and antioxidant properties of qingke wort as well as elucidate the mechanisms of mashing conditions affecting the quality of qingke wort. The results showed that wort with a high fermentable sugar content, including maltose and glucose, could be obtained using a crushed size smaller than 0.9 mm. Furthermore, enzyme treatment further led to an increase in fermentable sugar content, enhancing the fermentation capacity of qingke wort. Notably, crushing significantly affected the antioxidant properties of qingke wort, with smaller crushed particle sizes yielded superior antioxidant properties to the wort, mainly due to the increase in the content of phenolic compounds such as chlorogenic acid, caffeic acid, and epicatechin.

Quantitative analysis of key components in Qingke beer brewing process by multispectral analysis combined with chemometrics

In order to monitor the Qingke beer brewing process in real time, this paper presents an analytical method for predicting the content of key components in the wort during the mashing and boiling stages using multi-spectroscopy combined with chemometrics. The results showed that the Neural Networks (NN) model based on Raman spectroscopy (RPD = 3.9727) and the NN model based on NIR spectroscopy (RPD = 5.1952) had the best prediction performance for the reducing sugar content in the mashing and boiling stages; The partial least Squares (PLS) model based on Raman spectroscopy (RPD = 2.7301) and the NN model based on Raman spectroscopy (RPD = 4.3892) predicted the content of free amino nitrogen best; The PLS model based on UV–Vis spectroscopy (RPD = 4.0412) and the NN model based on Raman spectroscopy (RPD = 4.0540) are most suitable for the quantitative analysis of total phenols. The results can be used as a guide for real-time control of wort quality in industrial production.

Enhancement of dimethyl sulphide separation during wort boiling by a single spinning cone evaporator

Wort boiling is the most energy intensive stage in the brewing process. Novel wort boiling systems have been explored to reduce primary energy consumption and improve wort quality and beer flavor stability. Low thermal stress boiling is proposed for wort boiling, but the content of dimethyl sulphide (DMS) in the wort may exceed the required product threshold. A single spinning cone evaporator (SCE) is proposed to enhance the separation of DMS and minimise the energy consumption for wortboiling. The performance of a SCE was evaluated by measurement of fluid flow, ratio of DMS removal, wort self-evaporation ratio based on sensible heat, and thermal efficiency. The results show that use of a spinning cone evaporator, reduced DMS by up to 90% with 2.1% wort self evaporation ratio with less primary heat consumption. The SCE operation exceeds the evaporation of a gravity film cone. Under reduced pressure, the spinning cone evaporator was less effective in DMS removal.

Barley varieties registered in the Slovak Republic after the harvest 2022

The study presents the results of technological quality and agronomic characteristics of the spring barley LG Flamenco and winter barley Sonja. These varieties have passed three-year trials within the state varietal trials of the Slovak Republic. At the optimum nitrogen content in unmalted grain, the LG Flamenco variety showed an extract content of 83.2% and the Sonja variety 81.4%. The diastatic power was at the optimum level for both varieties (316 and 411 WK un.). The Kolbach index was at the optimum level (48.3%) for LG Flamenco and 39.6% for Sonja. In the LG Flamenco variety, cell wall degradation was given by a friability value of 88% and a β-glucan content of 192 mg/l. The friability value for the variety Sonja was 82% and the β-glucan content was 193 mg/l. The quality (apparent final attenuation) of the sweet wort was satisfactory for both varieties (81.0%).

Effects of the mashing process and macromolecule contents on the filterability of barley malt.

The filterability of barley malt is a critical quality parameter in beer brewing. The effects of two mashing processes (processes A and B) on the filterability of the three barley malts and their macromolecule contents were investigated. Filtration volume increased by 4%, 9%, and 13% for the Baudin, Ganpi, and Gangpi malts, respectively, and the final filtration volume of Gangpi was still poorer than that of Baudin. A downward mashing process (process C) was applied to measure the β-glucan, arabinoxylans (AX), the polymeric arabinoxylan (PAX), and high molecular weight nitrogen (HMWN) content. The β-glucan degradation rate of well-modified malt during malting was higher than that of poorly modified malt, whereas the PAX and HMWN solubilization rates during malting were lower in well-modified malt than in poorly modified malt. The filterability of poorly modified malt did not effectively improve with an initial mashing phase at 37℃. β-Glucan degradation and PAX and HMWN solubilization during malting were critical for ensuring malt quality. Thus, the goal of predicting the filterability of malt was achieved by applying a downward mashing process. PRACTICAL APPLICATION: Quality of wort and beer as well as production efficiency is affected by the malt quality. The filterability of barley malt can affect the production efficiency and quality of wort. The change in the macromolecule contents during malting is important to ensure the production of high-quality malt. The results of this study can provide a good method for the detection of malt filtration performance, and it also may contribute to the purpose of prediction the changes in barley malt and the resulting barley malt filterability.

Effect of malting regimen on diastatic power, cold and hot water extracts of malts from sorghum

SummaryIn this study, sorghum grains were malted using different malting regimens and the malt qualities were analysed for cold water extract (CWE), hot water extract (HWE) and diastatic power (DP). Results showed that malting regimen produced sorghum malts with peak CWE, HWE and DP within the pre‐determined limits of malting regimen. From this, predictive models of sorghum malt quality were developed and tested. Whilst steeping duration interacts significantly with the germination period to cause variations in CWE and HWE, only the germination period significantly influenced the DP of sorghum malts. However, the kilning temperature showed no significant impact on the parameters studied. Besides CWE, HWE and DP correlating positively with each other, the developed predictive models were significant (P < 0.05) and satisfy the quality of fit (R2 > 0.70) of the proposed models. The result demonstrated that wort for different purposes can be obtained by varying the malting operational conditions in the predictive model, thus saving time, resources, preliminary studies and research designs. Besides the promotion of a cheaper local alternative material for industrial wort production and brewing purpose, this research provides valuable insight on the brilliant prospect of variable malting regimen in predicting and adjusting the quality characteristics of sorghum malt and wort. Future studies are required to develop models for wort produced from peak CWE, HWE and DP, for predicting wort quality characteristics.

Research of the quality of dense wort for production of special purpose beer

Currently, the brewing industry in Kazakhstan is one of the leading in the production of beverages. Expanding the range, improving the functional properties of the drink is one of the conditions for competitiveness in the market of Kazakhstan and beyond. In this regard, production facilities strive to improve technology, use non-traditional raw materials, natural ingredients. One of the directions that will make it possible to obtain special-purpose beer is the use of high-density brewing with the use of syrups from nontraditional raw materials and the selection of production modes. This article explores the possibility of using Jerusalem artichoke syrup to obtain a dense wort and increase its functional properties. The results of the study showed the optimal use of syrup in a ratio of 70:30 to the wort in the process of boiling the wort with hops. That will allow you to get the wort with the specified characteristics: extractability - 15.9%, density - 1.0630 and the highest organoleptic characteristics. The content of vitamins in the developed wort can satisfy the daily requirement of the human body by 40-50% and determine the functional properties of the dense wort.

Sweet sorghum: broth clarification with enzymatic treatment increases the quality of the fermentation wort for ethanol production

Sweet sorghum is currently being evaluated throughout the world as a raw material for biofuel production because its stem juices are rich in sugars that can be directly fermented to ethanol. In this work, the fermentative efficiency of three sweet sorghum genotypes was evaluated, aiming at ethanol production, harvested in two seasons, clean and whole stems, and the treatment of the juice and broth with amylolytic enzymes in order to use the present starch to increase the production of ethanol. The experiment was carried out in the 2013/2014 harvest, in the municipality of Jaboticabal, São Paulo, Brasil, located at 21°14’05’’S and 48°17’09’’W. The experimental design was completely randomized, with sub-subdivided plots and four replications. The primary treatments were the sweet sorghum genotypes (CV147, CV198, and BRS508), the secondary treatments, the type of harvest (whole stems and clean stems); the tertiary the two sampling times (102 and 116 days after sowing - d.a.s) and the quaternary the application of enzymes. In the fermentation process, the yeast PE-2 was used, at the end, the wine was recovered and characterized. Fermentation efficiency and liters of ethanol per ton of sorghum were calculated. The clarification of the juice with enzymatic treatment increases the quality of the fermentation broth and makes it possible to obtain wines with lower levels of RRTs and Brix. Fermentation efficiency is not affected by the genotype; however, it is influenced by the time of harvest and the technological quality of the juice. The use of amylolytic enzymes makes it possible to obtain wines with lower levels of RRTS and Brix. The best period of industrialization was at 102 d.a.s., and the processing of whole stalks resulted in less ethanol production.

Barley varieties registered in the Czech Republic after the harvest of 2020

The study presents malting quality and agronomic characteristics obtained during testing of barley varieties in the Czech Republic. After the harvest of 2020, the following spring barley malting varieties were registered: Amidala, Focus, Greenway, KWS Jessie, LG Belcanto, and LG Stamgast. LG Stamgast was recommended for production of the beer with the protected geographical indication České pivo. In addition, the non-malting spring barley variety RGT Gagarin was registered. Amidala, Focus, Greenway, KWS Jessie, LG Belcanto provided malt with the extract content over 83%. These varieties also easily degraded nitrogenous substances. The value of the Kolbach index ranged from 48.6 to 52.1%. Diastatic power was at the optimal level. Degradation of cell walls was also optimal. Friability moved from 89 to 97% and β-glucan content in wort achieved satisfactory values of 65 – 170 mg/l in the given varieties . Wort quality, which is characterized by final attenuation, was at the above average to optimal level of 80.9 – 83.2% in these varieties of spring barley. LG Stamgast showed lower values of proteolytic and cytolytic modification and lower values of final attenuation, which is required for the varieties recommended for the production of the beer with the protected geographical indication České pivo.

Effect of Kilning Temperature on Some Physico-Chemical Properties of Malt

The character and the quality of the malt is affected during kilning. Mashing and wort quality is also affected during kilning of malt. Accordingly an experiment was conducted on the malt quality parameters for malts kilned in different temperature. In Ethiopia, there is high demand of quality malt for new emerging bear industries. Thus, this research aims to evaluate the effect of kilning temperature of selected barley variety Holker from Kulumusa research center Ethiopia. The kilning of germinated barley was performed at four different temperatures (50˚C, 70˚C, 90˚C and 110˚C) in order to produce four different malts. The experiment contained in combination of the four kilning temperatures laid out in complete randomized design with three replications. As a result, all investigated malt quality assessing parameters which includes the hot water extract, color, pH, malting weight loss and the wort viscosity were significantly different among the different treatment temperatures. Malts treated with 50˚C and 70˚C gave good malt quality containing higher hot water extract (79.7 and 75.17%), a normal color (2.32 and 2.63), standard pH (6.53 and 5.99), acceptable malting weight loss (0.60 and 1.55) and appropriate wort viscosity (1.66 and 1.62cp), respectively. Keywords : Malt, Kilning, Temperature, Physico-Chemical, Barley DOI: 10.7176/FSQM/106-01 Publication date: March 31 st 2021

Barley varieties registered in the Czech Republic after the harvest of 2019

The study presents results of malting quality and agronomic characters determined within varieties of Avus, Fandaga, and LG Tosca after a three-year period of testing and Adam and LG Ester after four years of testing with the purpose of obtaining the registration of these spring barley varieties in the Czech Republic. Adam and LG Ester were recommended for the production of beer with the Protected Geographical Indication “České pivo”. Extract from the varieties was at the levels of 82.6 and 81.9%. They exhibited the required lower level of proteolytic modification and apparent final attenuation. Cytolytic modification was also low. Avus, Fandaga, and LG Tosca had a high extract in malt dry matter, which ranged from 83.4 to 84.1%. The varieties had optimal to strong proteolytic modification (the Kolbach index of 46.8–55.6%). Fandaga exhibited the highest content of free amino nitrogen (246 mg/l). Amylolytic and cytolytic modifications were at the optimal level. Wort quality was optimal (apparent final attenuation was between 82.1 and 83.2%). LG Tosca always provided clear wort while other varieties provided weakling opalizing wort.

Barley varieties registered in the Slovak Republic after the harvest of 2019

This study presents the results of malting quality and agronomic characters obtained within state varietal testsof malting barley in the Slovak Republic. After the harvest of 2019, new spring malting barley varieties of Avus,Bernet, and LG Nabuco were registered. The spring barley varieties provided malt with extract content above 83%. All varieties degraded nitrogenous substances easily. The values of Kolbach index ranged from 47.5 to 49.5%. Diastatic power was at the optimal level and moved above the level of 300 WK un. in all the studied varieties. Also, cell wall degradation was optimal and friability was higher than 90%. Content of β-glucans in wort reached favourable values (72–141 mg/l). Quality of wort characterized by apparent final attenuation was at the above average value to the optimal level (81–81.8%) in the studied spring barley varieties.

Effect of hydrogen peroxide and ozone treatment on improving the malting quality

The effect of hydrogen peroxide (HP) and ozone (O3) treatment during barley steeping on the quality of malt produced from two barley varieties (GrangeR and AC Metcalfe) by micro-malting was investigated. The two steeping oxidation treatments that was observed to promote barley acrospire growth. Ozone treatment improved the malt enzyme activity of endo-protease, α-amylase, free beta-amylase and total limit dextrinase to differing extents, with GrangeR improving to a greater degree. HP treatment contributed to the increase of α-amylase, β-glucanase and endo-protease. Surprisingly, HP or ozone oxidation during malting resulted in different and novel outcomes for total beta-amylase in GrangeR and AC Metcalfe. In GrangeR, total beta-amylase activity reduced with respect to the control in both treatments. In comparison with AC Metcalfe there was a substantial increase of 78% with HP and 90% O3 in total beta-amylase activity. Malt quality including wort free amino nitrogen, β-glucan, turbidity and diastatic power was differentially increased by the oxidation induction treatment during steeping in malting. Gene expression analysis indicated that the effects of the steep oxidation treatments on enzyme and malt quality were putatively linked with the up-regulation of certain genes involved in GA synthesis (GA20ox1) and ABA catabolism (ABA8′OH). Barley grain germination assay results also showed that moderate HP induction could improve barley germination tolerance to the ABA effect. Malting including steep oxidation induction was shown to be beneficial to malt quality by improving the resultant wort quality and the efficiency of the beer brewing process. These observations point the way towards improving malt quality and the efficiency of the malting process.

Barley varieties registered in the Slovak Republic after harvest 2018

After completing the state varietal tests, the spring barley malting varieties Chimbon, Laureate and LG Aurus, and were registered in the Slovak Republic. Extract content in dry matter in the studied varieties was high and moved in the scope of 83.1 – 83.5 %. The varieties had strong proteolytic modification (Kolbach index 49.5 – 50.7 %). Amylolytic and cytolytic modification was at the optimal level. Wort quality was optimal (apparent final attenuation 81.5 – 82.2 %). The studied varieties gave clear wort, with the exception of the variety Accordine with the weakly opalizing wort.

Використання несолодженого ячменю в пивоварінні

Мета: Основною сировиною для виробництва пива є солод. Існує тенденція щодо використання інших зернових культур у пивовиробництві. Використання несолоджених матеріалів дає можливість пивоварам та технологам знижувати собівартість продукції. Але часткова заміна солоду однозначно впливає на якість сусла та готового пива. Основною метою дослідження було порівняти якісні показники пива, звареного лише із використанням солоду, та пива, звареного із частковою заміною солоду несолодженим ячменем. Методи дослідження: Для розв’язання даної проблеми було використано метод високоефективної рідинної хроматографії, аналізу та емпіричний методи досліджень. Результати: Використання великої кількості несолоджених матеріалів разом із допомогою ферментних препаратів дає пивоварам можливість отримувати продукт такого ж складу та якості, як при використанні тільки солоду. Висновки: Для пивоваріння із заміною великої кількості солоду, ячмінь є одним із найкращих варіантів, так як має багато характеристик солоду. Заміна частини солоду несолодженими матеріалами є можливою, економічно вигідною та технічно обґрунтованою при використанні ферментних препаратів.