Final Beer Research Articles

Assessment of the water footprint of the brewery industry: The case of Heineken, Addis Ababa, Ethiopia

The brewery industry is among the most water-intensive sectors, typically consuming 4–6 L of water for every liter of beer produced, necessitating a strong focus on water sustainability. Therefore, this study aimed to quantify the water footprint (WF) of the Heineken Ethiopian beer industry in Addis Ababa (Kilinto) over five consecutive years to identify water-intensive processes and areas. A stepwise accumulative and bottom-up approach was used to measure this WF, including calculations for both the final beer product and the spent grain byproduct. In 2019 and 2020, a significant portion of water consumption was attributed to spent grain extraction. By 2023, although the blue water footprint of both products remained within sustainable limits, more water was used in producing the final beer than in extracting spent grain. This suggests rapid improvements in water efficiency within the brewery, likely driven by effective water management practices such as leak detection and the use of water-efficient equipment and processes. The WF assessments also evaluated four sections of the brewery: utility, brewing, packaging, and general services. While utility, brewing, and packaging sections demonstrated improved water efficiency over time, the general services section saw a decrease. Given that general services are the most water-intensive area, prioritizing water management strategies in this section is crucial for overall sustainability.

Mashing Isothermally at High Temperature Compared to Infusion Mashing for the Production of Full-Bodied, Alcohol-Reduced Beer

The objective of this study was to investigate the influence of the mashing temperatures on alcohol content and taste of bottom-fermented Pilsner style beers and to ascertain whether these beers exhibit comparable sensorial properties. For this purpose, three beers brewed with three different mashing procedures were compared. The worts produced were sampled during mashing and after boiling, and subsequently analysed for their original gravity, fermentable sugars, and free amino nitrogen. The beers were analysed for their alcohol content, aroma compounds, apparent degree of fermentation, pH value, foam, and bitterness units as well as being evaluated sensorially according to DLG (= “Deutsche Landwirtschafts-Gesellschaft - German Agricultural Society”) grading in the categories: odour, purity of taste, body, carbonation, quality of bitterness. Overall it was shown, that the isothermal mashing procedure yielded less fermentable but more unfermentable sugars than the two more traditional mashing procedures, leading to a comparable original wort of 11.6°P in the final beer and lower alcohol content of 2.8% v/v in comparison to the more traditional mashing procedures (“high-short” and “simplified high-short” mashing procedure) with original worts of 12.1°P and alcohol contents of 4.5% v/v and 5.0% v/v, respectively. The DLG-rating showed that the beers derived from the different mashing procedures were all classified similarly with scores above 4.5 on average (out of 5.0) in all categories with no significant differences.

Effect of different processing steps in the production of beer fish on volatile flavor profile and their precursors determined by HS-GC-IMS, HPLC, E-nose, and E-tongue

Beer fish is characterized by its distinctive spicy flavor and strong beer aroma. Currently, there is a lack of comprehensive research analyzing the changes in taste and volatile compounds that occur during the processing of beer fish. Thus, this study used HS-GC-IMS, electronic tongue, and electronic nose to investigate the changes in flavor components during various processing stages of beer fish. The obtained results were subsequently analyzed using multivariate statistical analysis. The results showed that the final beer fish product (SF) had the greatest amount of free amino acids (888.28 mg/100 g), with alanine, glutamic acid, and glycine contributing to the taste of SF. The inosine monophosphate (IMP) content of beer fish meat varied noticeably depending on processing stages, with deep-fried fish (FF) having the greatest IMP content (61.93 mg/100 g), followed by the final product (SF) and ultrasonic-cured fish (UF). A total of 67 volatiles were detected by GC-IMS, mainly consisting of aldehydes, ketones, and alcohols, of which aldehydes accounted for >37%, which had a great influence on the volatile flavor of beer fish. The flavor components' composition varied noticeably depending on the stage of processing. PLS-DA model screened 35 volatile flavor components (VIP > 1) as markers; the most significant differences were 1-propanethiol, isoamyl alcohol, ethanol, and eucalyptol. Ultrasonic processing, frying, and soaking sauce can significantly improve the formation of flavor compounds, resulting in a notable enhancement of the final beer fish's umami taste and overall flavor quality.

The two faces of microorganisms in traditional brewing and the implications for no- and low-alcohol beers.

The production of alcoholic beverages is intrinsically linked to microbial activity. This is because microbes such as yeast are associated with the production of ethanol and key sensorial compounds that produce desirable qualities in fermented products. However, the brewing industry and other related sectors face a step-change in practice, primarily due to the growth in sales of no- and low-alcohol (NoLo) alternatives to traditional alcoholic products. Here we review the involvement of microbes across the brewing process, including both their positive contributions and their negative (spoilage) effects. We also discuss the opportunities for exploiting microbes for NoLo beer production, as well as the spoilage risks associated with these products. For the latter, we highlight differences in composition and process conditions between traditional and NoLo beers and discuss how these may impact the microbial ecosystem of each product stream in relation to microbiological stability and final beer quality.

Screening of native Saccharomyces cerevisiae strains from Chile for beer production.

Beer is one of the most consumed alcoholic drinks in the world, and this industry is a growing market that demands different properties to satisfy new consumers. The yeasts are used in different fermented beverages to contribute to new flavors. However, yeast strains used in the beer industry are limited so far, thus the diversity of flavors is very restricted. Therefore, the use of native yeast strains has been taking more importance with the purpose of conferring differentiated organoleptic properties to the product. Based on this observation the potentiality of native Saccharomyces cerevisiae strains obtained from different localities in Chile was researched. In this work was selected those strains that produced the highest ethanol concentration (nearly 6% v/v), consumed the highest amounts of sugars, and produced the lowest amounts of organic acids in the resulting beers. Finally, we did a beer tasting to select those strains that added different flavors to the final beer compared with a commercial strain used. In this study, two native strains that produced fruity descriptors are described, which could be used in the future in brewing, craft or industrial production.

The impact of lager brewing yeasts on flavor stability of pilot-scale beer during storage

AbstractThe aim of the present study was to investigate the impact of two lager brewing yeasts (KVL001 and KVL018), known to produce different levels of sulfite and thioredoxin, on the flavor stability of beer during storage for 24 weeks at 25 °C and 35 °C. Fermentations with the two yeast strains were carried out in two identical pilot scale brews and provided fresh beers with very similar sensory profiles, only differing significantly in content of sulfite, iron, thioredoxin, and free amino acids. No difference in protein thiols was observed indicating that thioredoxin was not active in the final beer. The yeast strain KVL018 consumed less free amino acids than KVL001 resulting in fresh beers with a higher content of free amino acids. During storage, the beers developed very similarly, but the beers fermented with KVL018 developed more 'fruity aged/vinous' flavor, especially at 35 °C. This suggested that a higher degree of the Maillard reaction took place in these beers due to the higher content of free amino acids. Beers fermented with KVL018 also contained more sulfite and less iron, but scored lower in the general evaluation of the sensory analysis. In conclusion, our results indicate that the yeast strain (KVL001) taking up more free amino acids resulted in more flavor-stable beer due to a lower degree of the Maillard reaction, while no clear effects were observed on oxidation.

Development of gluten-free craft beer: Impact of brewing process on quality attributes and consumer expectations for sensory properties.

To date, few studies investigated the differences between the two main gluten-free (GF) brewing techniques, such as the use of enzymes and the use of unconventional GF grains in brewing, by consumer perspective. In this study a GF beer brewed with sorghum and quinoa, as brewing adjuncts, was compared to the enzymatic-treated counterpart, in order to evaluate the effect of deglutinization treatment on physicochemical, volatile, and sensory characteristics of final beer. Moreover, the influence of brewing process and raw materials information on consumers' sensory perceptions, willingness to buy (WTB) and willingness to pay (WTP) was also investigated (n=105 consumers), under blind (B), expected (E), and informed (I) conditions. The enzymatic-treated sample showed comparable physicochemical attributes with the untreated counterpart, except for a significant reduction in color and foam stability (p<0.05). Non-significant difference between samples was found in the overall liking, WTB, and WTP mean scores in all three sensory test conditions (p>0.05). The information about the deglutinization treatment had a negative impact on overall liking (p<0.01), although WTP for both samples was significantly higher in the informed test than in blind condition (p<0.05). Overall, Check-All-That-Apply test results confirmed that the deglutinization treatment does not affect the beer sensory profile, even if the information about brewing ingredients and technologies may slightly influence the consumers' sensory perception. Therefore, this result proves that it is possible to produce a marketable GF beer, simply by partially replacing 40% of barley malt with unconventional GF grains, without using enzymes for gluten reduction purpose.

Maiorca wheat malt: A comprehensive analysis of physicochemical properties, volatile compounds, and sensory evaluation in brewing process and final product quality

This study explores the potential of Maiorca wheat malt as an alternative ingredient in beer production, investigating its impact on the brewing process and beer quality at different recipe contents (50 %, 75 %, 100 %). The study encompasses a comprehensive analysis of key malt parameters, revealing Maiorca malt’s positive influence on maltose, glucose, filterability, extract, free amino nitrogen, and fermentability. Notably, the malt exhibited heightened levels of α-amylase and β-amylase enzymes compared to conventional commercial malt. Furthermore, the analysis of aroma compounds and subsequent sensory evaluations unveiled a significant correlation between the proportion of Maiorca malt in the formulation and intensified estery, fruity, malty, honey, complemented by a reduction in attributes such as aromatic compounds, phenolic, yeasty, sulfury, oxidized, and solvent-like odors. This research underscores the favorable contribution of Maiorca wheat malt to enhancing both the brewing process and final beer quality, highlighting its potential as an innovative ingredient in brewing practices.

Study of Sulphides Production Affecting the Fermentation Process of the Lager Beer

In the lager brewing production process, volatile sulphides such as sulphur dioxide, hydrogen sulphide, thiols and thioesters are produced by yeast metabolism during the fermentation of lager beer. Fluctuations in malt raw materials, yeast strain characteristics and fermentation process parameter adjustments can all have an impact on sulphides, and the concentration of sulphides in finished beer can have a negative impact on the sensory tasting of lager beer. This study investigated the fermentation of sulphides in lager beer under the conditions of dissolved wort oxygen, yeast recovery, fermentation temperature and pressure, and the results showed that the longer the yeast growth time, the later the fermentation of sulphur dioxide and the lower the sulphur dioxide content in the final beer by 10mg/L. The longer the yeast recovery days, the higher the fermentation of sulphur dioxide and hydrogen sulphide. The higher the content, the higher the fermentation temperature of the lager and the faster the fermentation rate, which favours a low sulphur dioxide content at the end of the main fermentation.

Wheat craft beer made from AFB1-contaminated wheat malt contains detectable mycotoxins, retains quality attributes, but differs in some fermentation metabolites

Levels of aflatoxin B1 (AFB1) were measured during the production of wheat craft beer made with wheat malt contaminated with AFB1 (1.23 µg/kg). A wheat craft beer made with non-contaminated wheat malt was produced for comparison purposes. AFB1 was measured after mashing (malt after the mashing process), and in spent grain (spent grains are filtered to collect the wort - remaining sugar-rich liquid), sweet wort, green beer, spent yeast, and in beer. Physicochemical parameters (pH, titratable acidity, color parameters, total soluble solids), sugars, organic acids, alcohols, and phenolics were evaluated after mashing, and in sweet wort, green beer, and beer samples. Density and yeast counts were determined over 120 h of sweet wort fermentation every 24 h. The AFB1 levels in the final beer were 0.22 µg/L, while the spent grains and spent yeasts contained 0.71 ± 0.17 and 0.11 ± 0.03 µg/kg of AFB1, respectively. AFB1 contamination did not influence the final product's physicochemical parameters, density during fermentation, fructose, or glycerol content. Higher yeast counts were observed during the first 48 h of non-contaminated wheat craft beer fermentation, with higher ethanol, citric acid, and propionic acid contents and lower glucose, malic acid, and lactic acid contents compared with beer contaminated with AFB1. Non-contaminated wheat craft beer also had higher concentrations of gallic acid, chlorogenic acid, catechin, procyanidin A2, and procyanidin B1. AFB1 contamination of wheat malt may not affect basic quality parameters in wheat craft beer but can influence the final product's organic acid and phenolic contents. Our findings show that if wheat craft beer is made with contaminated malt, AFB1 can remain in the final product and may pose a risk to consumers.

Variability in the levels of fungicide residues in final beer as they are influenced by various sequences of agrochemicals used for treatment on hops

The fate of during brewing of pesticides (organic compounds and copper) from hops was determined to reveal linkages between various pesticide sequences applied in hop yards and the level of pesticides in beer. For this purpose, laboratory-scale brewing trials were carried out with conventional hops from four localities in which pest control spray programs varied. Pesticide residue analysis in samples of hopped wort, young beer, and beer was carried out by liquid chromatography in tandem with mass spectrometry (LC-MS/MS). Cu concentrations were determined using inductively coupled plasma mass spectrometry (ICP-MS). The transfer rates (%) of individual pesticides were calculated to demonstrate their ability to be transferred from hops to the brewed solutions. The pesticides exhibited different transfer rates correlating well with their log p values; however, the obtained transfer data were not related to their concentration in hops. The average transfer rates calculated for ametoctradin (15% ± 5%), mandipropamid (38% ± 4%), boscalid (48% ± 5%), and azoxystrobin (47% ± 2%) increased in good correlation with their descending log P values. On the contrary, the transfer rates of copper residues were related to residual concentrations of copper in hops and exhibited logarithmic dependency. The carryover of the sum of all pesticides in the four samples ranged from 36% to 49%, averaging 42% ± 6%. The data showed no substantial influence of various pesticide spray sequences on the percentages of overall pesticide residues carried over into beer.

Evolution of Alternaria toxins during the brewing process and the usability of optical sorting methods to reduce mycotoxin concentrations in beer

To assess the impact of black-colored grain on Alternaria mycotoxin concentrations in different stages of the brewing process, brewing experiments were conducted in a microscale brewhouse. Different mixtures of visually unaffected and black-colored batches of two malt samples were used, which were obtained by an optical sorting device. The 13 Alternaria mycotoxins alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), tentoxin (TEN), alterperylenol (ALTP), altertoxins I and II (ATX I and II), altenuene (ALT) as well as the modified forms AOH-3-glucoside (AOH-3-G), AOH-9-glucoside (AOH-9-G), AME-3-gluoside (AME-3-G), AOH-3-sulfate (AOH-3-S) and AME-3-sulfate (AME-3-S) were analyzed in each processing step by liquid chromatography–tandem mass spectrometry (LC–MS/MS), and the toxin concentrations were balanced over the whole brewing process. Fungal DNA content in the starting material (mixtures) was determined by quantitative real-time polymerase chain reaction (qPCR). In this study, TeA was the only toxin to migrate into the final beer, while the AOH, AME, TEN, ALTP and ATX I toxins were mainly found in the spent grains. The observance of AOH-3-S and AME-3-S in some processing steps also showed the possibility of modification reactions during brewing. Furthermore, no distinct correlations between the fungal DNA and the analyzed mycotoxins could be observed in the starting material, while the amount of black colored grains only impacted toxin concentrations in one of the two used malt samples. Nevertheless, it was shown that optical sorting of malt batches might be a useful tool for the malting and brewing industry to prevent elevated mycotoxin concentrations.

Italian Grape Ale Beers Obtained with Malvasia di Candia Aromatica Grape Variety: Evolution of Phenolic Compounds during Fermentation.

Italian grape ale (IGA) beers have been categorized by the Beer Judge Certification Program as a sub-category of fruit beers in which grape, or grape must, is added during the brewing process to provide additional characteristics to the final beer. In the present work, IGA beers have been produced with must and pomace of the Malvasia di Candia Aromatica (MaCA) grape variety, which were added before fermentation at two different percentages (10% and 20%). The (poly)phenolic profile of IGA beers have been characterized with HPLC-MS/MS and compared to a golden ale control beer (produced in the same conditions without the addition of grape-derived ingredients). A series of sub-samples have been collected to monitor the (poly)phenol profile at time 0 and during the different phases of the fermentation process (1, 3, 5, 7 30, 65 days). Results demonstrated how the addition of pomace allowed to significantly enrich (p < 0.05) final beers in total (poly)phenols detected by MS, while must addition did not influence that amount if compared to the control sample. However, a PCA cluster analysis identified strong similarities among IGA beers and differentiated them to control beer samples. This study underlined how the addition of must and pomace from the MaCA grape variety improved the (poly)phenolic profile of beer from both a qualitative and quantitative point of view.

A Comprehensive Comparison of Gluten-Free Brewing Techniques: Differences in Gluten Reduction Ability, Analytical Attributes, and Hedonic Perception

This study provides a comprehensive comparison among the most common gluten-free (GF) brewing practices, with a focus on the impact of each treatment on physicochemical parameters and consumer acceptability of the final beer. In addition, the influence of a longer cold maturation on the natural reduction of the gluten content was investigated. Prolyl endopeptidase addition was found to be the most effective treatment in reducing gluten levels (−75.93%), followed by silica gel (−53.09%), longer cold maturation (−4.32%), and tannins (−1.85%). Nonetheless, none of the treated beer samples was gluten-free (gluten content &gt; 20 ppm) due to the high nitrogen content of the original wort. The silica gel application treatment affected the physicochemical and sensory characteristics of the final beer the least. According to the difference from control test results, no significant difference in terms of overall liking, appearance, odor/aroma, or taste was observed between the silica gel-treated sample and control beer (p &gt; 0.05). On the other hand, the application of enzymes and tannins significantly affected the appearance and the beer odor/aroma. Nevertheless, all beer samples received positive sensory acceptance scores.

Use of Unmalted and Malted Buckwheat in Brewing

With the goal of introducing specialty beers with full flavor and effective processing, craft and functional beer have revived old assortments and established new assortments in countries throughout the world. These unique selections are produced utilizing various ingredient combinations or changes to the brewing process. Given the rise in celiac disease sufferers in recent years, research investigations on the use of buckwheat in brewing, particularly gluten-free beer, have intensified. In this study, malted and unmalted buckwheat were proposed for use in brewing, and the results were contrasted with those of beer made entirely of malted barley. Commercial enzymes were added to the technical mashing process in order to optimize it and increase output yield. It was simple to incorporate buckwheat in the technological process to produce a final product that, in many respects, resembled conventional beer, making buckwheat suitable for regular beer drinkers. In terms of original extract, apparent extract, alcohol content, and energy value, the beer obtained from 100% barley malt differs from the final beer, but only minor variations were found in color, pH, and bitterness value. Ethyl alcohol, a particularly significant distinguishing characteristic, was impacted by the use of buckwheat malt and unmalted buckwheat. The beer made from buckwheat was acceptable from a sensory perspective in terms of flavor, aroma, texture, bitterness, etc. The results demonstrate that the researched raw materials can be successfully used in the production of beer, both in malted and unmalted forms. For the latter option, it is recommended to use enzyme preparations to speed up the mashing and filtration of the wort.

The effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer.

The present work explored the effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer. Results illustrated that the addition of wheat malt can significantly improve the soluble protein of wort and the final beer, and it can provide more>2.2kDa protein in final beer, which is mainly derived from the raw wheat malt, but also including some protein produced in the fermentation process, such as some protein between 29 and 66.4kDa. Though the content of>15kDa protein was relatively lower than the protein whose molecular weight was<15kDa, but it had important effects on total nitrogen, total water-soluble protein, free amino nitrogen, chromaticity, and viscosity of final beer. The addition of wheat malt significantly improved the concentration of 2.2-15 and>15kDa protein, but higher percentage of addition ratio can decrease the foam stability of the beer. PRACTICAL APPLICATION: This findings can reasonably control the protein content and types of wheat beer, improve the quality of wheat beer, solve the key technological problems, and expand and popularize the application of wheat in beer industry.

Gluten reduction in beer: Effect of sorghum:quinoa ratio and protein rest time on brewing parameters and consumer acceptability

The combined effects of the grist composition (sorghum:quinoa ratio) and mashing conditions (protein rest time) were investigated with the aim to reduce gluten content in beer and to evaluate their impact on the physicochemical parameters and consumers' acceptability of final beer. Principal Component Analysis results, which explained 72.65% of data variability, showed a good separation of beer samples according their grist composition. Using high sorghum concentrations (34 and 40%) led to a significant reduction (p < 0.05) in extract, Free Amino Nitrogen (FAN), alcohol, total nitrogen content and the colour of the final beer. Protein rest time showed a significant impact on the sensory attributes of beer samples; therefore, it should not exceed 30 min. Beer with the best brewing performance in terms of physicochemical attributes and consumers’ preference (considered as “like moderately” by 90 consumers) was formulated with 6 and 34% of unmalted sorghum and quinoa, respectively, and by performing 20 min of protein rest. Results from this study suggested that the use in brewing of unmalted sorghum and quinoa, in an optimized combination, allows to develop beer brewed with unconventional grains without adversely affect consumer acceptance and purchase intention.

Influence of kilned specialty malt odorant markers on the aroma composition and sensory profile of beer

Specialty malt beers are brewed with the intention of providing distinct flavour and colour. To this end, special malts have different chemical compositions. More specifically, the availability of enzymes, small peptides, organic acids, Maillard products, low-molecular weight sugars and amino acids depend on the malting procedure applied and thus vary between the malt styles. To investigate the influence of kilned specialty malts (KSM) on the properties of wort and beer, brewing trials were carried out adding 10 and 20% of pale ale, Vienna, Munich or melanoidin malt. Alongside sensory analysis, the aroma composition of each beer was investigated throughout their brewing processes, revealing significant losses of the KSM odorant markers after the boiling process. Statistical analysis indicated a major influence of KSM-derived Maillard aldehydes on the sensory profile of the beers. Finally, the transfer rates of the odorants were calculated from the malt to the beer, suggesting a high influence of the brewing process on the formation of KSM odorants and thus on the aroma composition of the final beer.

Application of non-Saccharomyces yeasts with high β-glucosidase activity to enhance terpene-related floral flavor in craft beer

The rising interest in craft beer urging for novel yeasts that provide diverse attributes. This research aimed to explore the potential of four non-Saccharomyces yeasts with high β-glucosidase activity in beer fermentation. Fermentation ability, adverse environment resistance and carbohydrate affinity were measured via growth and physiochemical parameters and, based on these results, a Candida glabrata (D18) yeast was selected for subsequent sequential fermentations. Aroma analysis of the fermented beer was then performed using gas chromatography-mass spectrometry, demonstrated that some glucoside-binding terpenes had been significantly increased. In two D18 involved groups, geraniol content increased 51.5/11-fold in the single and mixed fermentations, respectively, while linalool increased 1.36-fold in the mixed fermentation, providing the final beer product with unique floral and fruity characteristics. Principal component analysis and sensory evaluation were also applied to further demonstrate these distinctions. Overall, D18 was found to be a potential yeast for beer fermentation with unique properties.

Changes in bioavailability of zinc during malting process and wort production

Trace metals, particularly zinc, influence the growth and metabolism of yeast. In the literature the recommended concentration of zinc in pitching wort is > 0.15 mg/L; lower concentrations cause fermentation problems and reduce in consequence final beer quality. The aim of this study was the exploration of changes in bioavailability (available zinc), which was never considered before, and in the mass balance of total zinc during malting process and wort production. Therefore, the work comprised two parts: (1) investigating the effect of malt modification on zinc content and bioavailability of, respectively, produced malt depending on malt modification by varying the steeping degree (38–48%) in the malting process and (2) examining the effect of zinc losses and changes in bioavailability in the by-products (spent grain and hot break) by performing brewing trials up to pitching wort. Zinc was measured by atomic absorption spectroscopy. We applied a specific extraction scheme to evaluate first the bioavailability of zinc in brewing-related samples. In the malting process, total zinc losses increased with greater modification level of the malt samples, although bioavailability increased simultaneously. Spent grain was the primary zinc loss by-product (98%) in the brewing process. The distribution of the binding forms of zinc in hot break and spent grain was significantly altered with an increase in the less water-soluble binding forms of zinc.