Search Results (100)

Beer is an alcoholic beverage made primarily from malted cereals, water, hops, and yeast. Although barley is the most common cereal in brewing, corn malts are also used to produce beer in different countries. However, research on their production, physicochemical properties, and aging evolution is limited. In the present study, the evolution of various physicochemical features during the aging of six lager- and ale-fermented corn beers was investigated. Results after 18 months of aging showed decreases in most of the measured properties: total phenolics between 16 and 20%, antioxidant capacity between 17 and 23% by DPPH assay and 23–41% by ABTS assay, free anthocyanins between 38 and 55%, bitterness units between 32 and 42%, and SRM color and color intensity only dropped in lager beers, while in ale beers these properties increased. Finally, tonality increased in lager beers and one ale beer. This study enabled a more in-depth analysis of corn beer, focusing on the evolution of physicochemical properties during aging that are relevant to beer quality. Full article

This study addresses the ongoing challenge of accurately classifying beers by fermentation type and product category, an issue of growing importance for quality control, authenticity assessment, and product differentiation in the brewing sector. We applied a multiblock chemometric framework that integrates phenolic profiling obtained via GC–MS, antioxidant and antiradical activity derived from in vitro assays, and complementary colorimetric and physicochemical measurements. Principal Component Analysis (PCA) revealed clear compositional structuring within the dataset, with p-coumaric, gallic, syringic, and malic acids emerging as major contributors to variance. Supervised machine-learning classification demonstrated robust performance, achieving approximately 93% accuracy in discriminating top- from bottom-fermented beers, supported by a well-balanced confusion matrix (25 classified and 2 misclassified samples per group). When applied to ale–lager categorization, the model retained strong predictive ability, reaching 90% accuracy, largely driven by the C* chroma value and the concentrations of tyrosol, acetic acid, homovanillic acid, and syringic acid. The integration of multiple analytical blocks significantly enhanced class separation and minimized ambiguity between beer categories. Overall, these findings underscore the value of multi-block chemometrics as a powerful strategy for beer characterization, supporting brewers, researchers, and regulatory bodies in developing more reliable quality-assurance frameworks. Full article

Recent studies have shown that the use of non-Saccharomyces yeasts, either alone or in co-fermentation with Saccharomyces cerevisiae, can enhance the development of specialty beers with distinctive compositional characteristics. This study aimed to evaluate the main compositional and sensory differences between American Pale Ale (APA) beers produced using the commercial strain S. cerevisiae US-05 as a single starter (Test 1), and those produced through sequential inoculation with Metschnikowia pulcherrima 62 followed by S. cerevisiae US-05 (Test 2). Analyses focused on key chemical parameters and volatile compounds at the end of primary fermentation (F1) and after 20 days of refermentation at 20 °C (F2). After F1, Test 2 samples showed higher concentrations of glycerol and higher alcohols (isoamyl alcohol, benzeneethanol) and lower concentrations of esters (isoamyl acetate, ethyl hexanoate, ethyl octanoate) compared to Test 1. After F2, the differences in higher alcohol content became less significant, whereas ester concentrations, particularly ethyl acetate and ethyl octanoate, were significantly higher in Test 2. Sensory evaluation revealed that beers from Test 2 exhibited more pronounced floral and fruity notes and achieved higher overall scores in the panel assessment. These findings indicate that sequential inoculation with M. pulcherrima 62 followed by S. cerevisiae enhances both the chemical complexity and sensory appeal of APA beers, highlighting the strain’s potential as a valuable tool for developing specialty beers with unique aromatic profiles. Full article

The craft beer market is continually expanding, driven by the consumers’ demand for product diversification, which leads to innovation in the brewing industry. While traditional brewing focuses on consistency and high-volume efficiency using standard yeasts, craft brewing prioritizes small-batch experimentation and flavor complexity. Traditionally, Saccharomyces cerevisiae (Ale beer) and Saccharomyces pastorianus (Lager beer) yeast are used in brewing. The craft brewing revolution introduced the use of non-conventional yeast. These yeasts possess distinct technological characteristics compared to commercial starters, such as a richer enzyme profile. This biological diversity produces beers with novel, complex aroma profiles, and opens exciting avenues for flavor creation. Recently, non-alcoholic beer and low-alcoholic beer (NABLAB), and functional beer have become the new horizons for the application of non-conventional yeasts. In recent years, the brewing potential of these alternative yeasts has been extensively explored. However, some aspects relating to the interactions between yeast and raw materials precursors involved in the aroma of the final beer, and the management of yeasts in fermentation, remain unexplored. This review systematically outlines the various innovative ways in which non-conventional yeasts are applied in brewing, including healthier beer. Here, we explore how these yeasts can foster innovation in the beer sector and provide the possibility for sustainable development in contemporary brewing. Full article

Fermentation is a complex biochemical process that transforms brewer’s wort into beer. Beer fermentation is driven by yeast and is influenced by process parameters such as the content of fermentable sugars in wort, temperature, and pH. Traditional methods of modelling this process rely heavily on empirically tuned kinetic models. However, these models tend to be recipe-specific and often require retuning when processes change. This paper proposes a data-driven approach using a Long Short-Term Memory (LSTM) network, a type of recurrent neural network, to model beer fermentation dynamics. By training the LSTM model on real-world fermentation data (1305 fermentations across ales, IPAs, lagers, and mixed-culture beers), including variables such as apparent extract (derived from specific gravity), temperature, and pH, we demonstrate that this technique can accurately predict key fermentation trajectories and support process monitoring and optimisation. When evaluated on representative medoid fermentations as one-step-ahead roll-outs over 0–300 h, the model produces accurate predictions with low errors and minimal residuals. These results show that the LSTM-based model provides accurate and robust predictions across beer styles and operating conditions, offering a practical alternative to traditional mechanistic kinetic models. This work highlights the potential of LSTM networks to enhance our understanding, monitoring, and control of fermentation processes, providing a scalable and efficient tool for both research and industrial applications. The findings suggest that LSTM models can be effectively adapted to model other fermentation processes in beverage production, opening new possibilities for advancing food science and engineering. Full article

Milk beer, a modern Chinese dairy beverage, is usually fermented by the co-culture of lactic acid bacteria (LAB) and Kluyveromyces marxianus (K. marxianus), with the latter known for its ability to produce aroma compounds. However, the accumulation of lactic acid produced by LAB can inhibit the growth of K. marxianus, which inevitably hinders the diversity and intensity of flavor compounds in milk beer. In this study, adaptive laboratory evolution (ALE) was applied to the parental strain Kluyveromyces marxianus CICC1953 (Km-P) under different concentrations of lactic acid to obtain an evolved strain Km-ALE-X20 with enhanced acid tolerance and increased titer of phenylethyl alcohol, which has a floral, rose-like aroma. Km-ALE-X20 demonstrated a 16-fold increase in OD₆₀₀ and a 28-fold increase in phenylethyl alcohol production compared with Km-P in chemically defined medium (CDM) containing 20 g/L lactic acid. Comparative genomics analysis suggested that mutated genes CTA1, TSL1, ERG2 were related to enhanced acid tolerance, while ARO8, ARO9, FKS2 were related to increased production of aroma compounds. Furthermore, Km-ALE-X20-fermented milk beer showed 33.87% and 32.43% higher production in alcohol and ester compounds than that of Km-P-fermented milk beer. Interestingly, sensory analysis showed that while Km-ALE-X20-fermented milk beer had higher sensory scores for rose and fruity aroma attributes, Km-P-fermented milk beer possessed a more balanced aroma profile. This paper highlights the first application of ALE to enhance the signature rose aroma of K. marxianus-fermented milk beer and provides an efficient framework for ALE-based breeding of aroma-producing food microorganisms. Full article

New England India Pale Ales (NEIPAs) are characterized by their hazy appearance and intense hop-derived aroma. These characteristics are central to their consumer appeal and market identity, yet the chemical drivers of these qualities remain poorly defined. This study aimed to investigate how hop profile influences NEIPA chemistry, emphasizing the role of Citra in defining volatile composition. Four profiles were evaluated: Single Hop, Citra; Multiple Hops, with Citra; Single Hop, Other; and Multiple Hops, without Citra. Volatile compounds were analyzed using a combination of sequential two-dimensional gas chromatography-mass spectrometry (GC–GC/MS) and one-dimensional gas chromatography-mass spectrometry (GC-MS). Multivariate statistical analysis was used to identify which compounds differentiated the four hop profiles. Esters, monoterpenes, and sesquiterpenes all contributed to differences across hop profiles. Inclusion of Citra hops yielded distinct volatile chemistry marked by isoamyl acetate, methyl geranate, ethyl cinnamate, and (E,E)-farnesol. By contrast, blended hop profiles showed greater chemical diversity. These findings demonstrate that hop blending alters beer chemistry beyond the sum of individual hops and identify key compounds that may serve as markers of blended versus single-hop NEIPAs. This work provides new insights into the chemical drivers of hop aroma complexity and establishes a framework for connecting hop usage, beer chemistry, and sensory outcomes. Full article

Beer is one of the most widely consumed alcoholic beverages worldwide, whereas surplus bread constitutes a significant environmental burden; repurposing this bread as a brewing adjunct offers a sustainable mitigation strategy. In this study, we replaced 50% of the malt grist in American Lager, India Pale Ale and Bavarian Weiss with stale whole wheat bread, brewed each beer and its malt control in duplicate, and stored them for 12 months at 15 °C. Bread addition raised turbidity and soluble protein at bottling; however, after 12 months, the bread lagers clarified to 101 NTU while the controls stayed above 600 NTU. Alcohol content, pH and titratable acidity were unaffected. All bread beers retained more total polyphenols and showed stronger DPPH radical-scavenging activity than controls, especially in lager and IPA. Lactobacillus (<100 CFU mL⁻¹) and Enterobacteriaceae (<10 CFU mL⁻¹) remained below detection limits in bread samples, whereas the malt-only Weiss displayed Lactobacillus spoilage. Sensory panels noted fuller body, livelier carbonation and enhanced toasted-malt aroma in bread beers, with no sensory off-flavour defects detected. Repurposing surplus bread therefore improves clarity, preserves bioactive compounds and yields distinctive, shelf-stable beers while advancing circular-economy goals. Full article

Sour beer production is strongly influenced by the choice of lactic acid bacteria (LAB), yet few studies have systematically compared strain-specific contributions under controlled kettle souring conditions. This study evaluated the fermentation performance and flavor-modulating potential of three LAB species—Lacticaseibacillus paracasei, Pediococcus pentosaceus, and Leuconostoc mesenteroides—in sour India Pale Ale (IPA) brewing. Growing assessments showed that P. pentosaceus exhibited the most rapid and stable proliferation, while L. mesenteroides required a longer adaptation period. Acidification trials demonstrated that L. paracasei achieved the lowest pH (3.26–3.43), contributing to intense sourness, whereas P. pentosaceus and L. mesenteroides yielded milder acidity (pH 3.41–3.65). Gas chromatography-mass spectrometry showed that P. pentosaceus and L. mesenteroides produced significantly higher levels of fruity and floral esters, including 2-pentanol propanoate, which was approximately 4-fold higher than in the control. Principal component analysis further distinguished the beers according to their volatile profiles. These findings highlight the strain-specific potential of LAB in sour beer brewing and provide practical guidance for flavor differentiation in craft beer production. Full article

This study investigates the impact of epigenetic modification on Saccharomyces cerevisiae using sodium butyrate (SB), a histone deacetylase inhibitor (HDACi), to enhance sensory characteristics in beer fermentation. Epigenetics offers a non-GMO approach to modifying gene expression, with potential for cost-effective strain development in brewing. A commercial ale yeast was cultured under different SB exposure regimes and used to ferment wort. Sensory evaluation was conducted with untrained participants, alongside GC-MS and enzymatic assays for ethanol, glycerol, and residual sugars. While no significant differences were found in ethanol production or smoothness and creaminess—likely due to uniform wort composition—flavor and taste scores varied between treatments. Notably, yeast pre-treated with SB but fermented without additional SB (1G W/O) received the highest flavor acceptability. Treatments involving SB during fermentation showed reduced sensory scores, likely due to butyric off-notes. Higher alcohol levels remained within acceptable thresholds and were more likely influenced by wort amino acid content than epigenetic modification. Though SB had a limited impact on metabolic pathways, this study highlights the feasibility of using dietary epigenetic modifiers to develop novel yeast strains with improved sensory profiles in beer or other fermented beverages and warrants further investigation with alternative compounds. Full article

Although beer fermentation has traditionally been carried out with Saccharomyces, the boom in craft brewing has led to the use of non-conventional yeast species for beer production. This group also includes non-Saccharomyces starters, which are commonly used in winemaking and which have different technological characteristics compared to standard representatives of the Saccharomyces genus. One of the important characteristics of the non-Saccharomyces group is the richer enzyme profile, which leads to the production of beverages with different taste and aroma profiles. The aim of this study was to investigate sweet and hopped wort fermentation with seven strains of active dry non-conventional yeasts of Lachancea spp., Metschnikowia spp., Torulaspora spp. and a mixed culture of Saccharomyces cerevisiae and Torulaspora delbrueckii. One ale and one lager active dry yeast strain were used as control strains. The extract consumption, ethanol production, degree of fermentation, pH drop, as well as the yeast secondary metabolites formed by the yeast (higher alcohols, esters and aldehydes) in sweet and hopped wort were investigated. The results indicated that all of the studied types of non-conventional yeasts have serious potential for use in beer production in order to obtain new beer styles. For the purposes of this study, statistical methods, principle component analysis (PCA) and correlation analysis were used, thus establishing the difference in the fermentation kinetics of the growth in the studied species in sweet and hopped wort. It was found that hopping had a significant influence on the fermentation kinetics of some of the species, which was probably due to the inhibitory effect of the iso-alpha-acids of hops. Directions for future research with the studied yeast species in beer production are presented. Full article

Wild ales represent a diverse category of spontaneously fermented beers, influenced by complex microbial populations and variable ingredients. This study employed an integrated metabolomic profiling approach combining proton nuclear magnetic resonance (¹H NMR) spectroscopy, liquid chromatography–mass spectrometry (LC-MS), and spectrophotometric assays (DPPH and FRAP) to characterize the molecular composition and antioxidant potential of 22 wild ales from six countries. A total of 53 compounds were identified and quantified using NMR, while 62 compounds were identified by using LC-MS. The compounds in question included organic acids, amino acids, sugars, alcohols, bitter acids, phenolic compounds, and others. Ingredient-based clustering revealed that the addition of dark fruits resulted in a significant increase in the polyphenolic content and antioxidant activity. Concurrently, herb-infused and light-fruit beers exhibited divergent phytochemical profiles. Prolonged aging (>18 months) has been demonstrated to be associated with increased levels of certain amino acids, fermentation-derived aldehydes, and phenolic degradation products. However, the influence of maturation duration on the antioxidant capacity was found to be less significant than that of the type of fruit. Country-specific metabolite trends were revealed, indicating the influence of regional brewing practices on beer composition. Correlation analysis was employed to identify the major contributors to antioxidant activity, with salicylic, dihydroxybenzoic, and 4-hydroxybenzoic acids being identified as the most significant. These findings underscore the biochemical intricacy of wild ales and exemplify metabolomics’ capacity to correlate compositional variation with functionality and authenticity in spontaneously fermented beverages. Full article

A rising demand for low-gluten beer fuels research into enzymatic solutions. This study optimized Aspergillus niger prolyl endopeptidase (AN-PEP) application timing during brewing to reduce gluten while preserving physicochemical quality. Ale-type beers were produced with AN-PEP (2% v/v) added at mashing, boiling, post-boiling, or post-fermentation, plus a control. Three mashing profiles (Mash A, B, C) were also tested. Gluten was quantified by R5 ELISA (LOQ > 270 mg/L). Color, bitterness, ABV, and foam stability were assessed. Statistical analysis involved ANOVA and Tukey’s HSD (p < 0.05). Enzyme activity and thermal inactivation were also evaluated. Initial gluten levels consistently exceeded LOQ. Significant gluten reduction occurred only post-fermentation. Mashing, boiling, and post-boiling additions effectively lowered gluten to below 20 mg/L. Post-fermentation addition resulted in significantly higher residual gluten (136.5 mg/L). Different mashing profiles (A, B, C) with early enzyme addition achieved similar low-gluten levels. AN-PEP showed optimal activity at 60–65 °C, inactivating rapidly at 100 °C. Physicochemical attributes (color, extract, bitterness, ABV) were largely unaffected. However, foam stability was significantly compromised by mashing and post-fermentation additions, while preserved with boiling and post-boiling additions. AN-PEP effectively produces low-gluten beers. Enzyme addition timing is critical: while mashing, boiling, or post-boiling additions reduce gluten to regulatory levels, only the beginning of boiling or post-boiling additions maintain desirable foam stability. These findings offer practical strategies for optimizing low-gluten beer production. Full article

Yeast genetic improvement is entering a transformative phase, driven by the integration of artificial intelligence (AI), big data analytics, and synthetic microbial communities with conventional methods such as sexual breeding and random mutagenesis. These advancements have substantially expanded the potential for innovative re-engineering of yeast, ranging from single-strain cultures to complex polymicrobial consortia. This review compares traditional genetic manipulation techniques with cutting-edge approaches, highlighting recent breakthroughs in their application to beer and wine fermentation. Among the innovative strategies, adaptive laboratory evolution (ALE) stands out as a non-GMO method capable of rewiring complex fitness-related phenotypes through iterative selection. In contrast, GMO-based synthetic biology approaches, including the most recent developments in CRISPR/Cas9 technologies, enable efficient and scalable genome editing, including multiplexed modifications. These innovations are expected to accelerate product development, reduce costs, and enhance the environmental sustainability of brewing and winemaking. However, despite their technological potential, GMO-based strategies continue to face significant regulatory and market challenges, which limit their widespread adoption in the fermentation industry. Full article

Beer is one of the most widely consumed alcoholic beverages and is rich in nutrients. Meanwhile, bread waste is a major contributor to global food waste. This study investigated substituting up to 50% of malt with whole wheat bread in American lager, Indian pale ale, and Bavarian weiss ale to reduce bread waste and enhance beer’s nutritional profile. The study assessed physicochemical properties, bioactive compounds, and volatile profiles of bread-based beers versus traditional malt-based brews. Results showed that bread beers maintained key properties while increasing bioactive compounds, especially in Bavarian weiss, which had higher total polyphenol content (1.04 mg GAE mL⁻¹ compared to 0.507 mg GAE mL⁻¹). Antioxidant activity in weiss beer also increased (2.007–2.057 μMol DPPH mL⁻¹ relative to 0.68–1.75 μMol DPPH mL ⁻¹ in 100% malt weiss). PCA analysis highlighted a distinct bioactive profile in bread beers, with elevated phenylethyl alcohol and ethyl octanoate. Substituting malt with bread was feasible, producing beers of comparable quality and potential health benefits. These findings support bread as a sustainable, cost-effective malt alternative, reducing waste and enhancing beer within a circular economy framework. Full article