Rice has served as a vital brewing adjunct for centuries, offering an alternative starch source to barley malt. Limited knowledge still exists regarding the factors influencing extract yield from adjunct rice, including rice cultivar and processing parameters. Therefore, the extract yield of 74 rice cultivars were evaluated. Extract yield of rice was determined using standard methods on a lab-scale mashing system. Extract ranged from 86.8 to 104.1% w/w% dry basis and was closely linked to rice cultivar and processing decisions. Kernel size did not have an impact on extract yield. High yielding extract cultivars had a higher propensity to fracture into smaller particle sizes and lower amylose percentage. Identifying cultivars with higher extract yield can enhance brewhouse efficiency and reduce raw material requirements. Overall, this could result in substantial cost savings for brewers and value-added opportunities for rice farmers and rice millers.

The fermentation of Sauce-Aroma Baijiu is a solid-state fermentation process with sorghum as the main raw material. The differences in physicochemical properties and microbial dynamics between waxy and non-waxy sorghums during the fermentation, as well as their effects on flavor compounds in Sauce-Aroma Baijiu, remain unknown. To investigate the impact of waxy characteristics of sorghum on the fermentation and flavor of Sauce-Aroma Baijiu, this study analyzed the starch structure and properties of pure waxy and non-waxy sorghums, and conducted liquor production experiments. High-throughput sequencing, flavor component analysis and sensory evaluation were comprehensively employed to study the differences in starch characteristics between pure waxy sorghums W1, W2 and pure non-waxy sorghums N1, N2, as well as their differences in physicochemical properties, microbial community evolution during fermentation. Compared with non-waxy sorghums, waxy sorghums showed higher amylopectin, water absorption, crystallinity and gelatinization enthalpy, which enabled slower starch release for multi-round fermentation. In terms of fermentation performance, the microbial community of waxy sorghums differ significantly from that of non-waxy sorghums, and the flavor profile was more closely resembles conventional base liquor, with flavor similarity exceeded 80%, while the base liquor yield was approximately 20% higher than non-waxy sorghums. This study provides a theoretical basis for selecting sorghum varieties for Sauce-Aroma Baijiu production, contributing to improve the quality of Chinese liquor.

The Hop Storage Index (HSI) is a widely used indicator of hop degradation, particularly in relation to the oxidation of bitter compounds. Since its introduction in the 1980s, the HSI has played a crucial role in hop selection, storage management, and brewing decisions. This review provides a comprehensive examination of the HSI, beginning with its historical development and the chemical basis underlying its measurement. The oxidation of bitter compounds and their transformation into derived products are discussed in relation to HSI values, along with an overview of the typical HSI ranges and their interpretation. The impact of storage practices on hop quality is also considered, emphasizing how different conditions influence HSI and, ultimately, brewing outcomes. Beyond bitterness, hop oxidation affects sensory properties, altering the overall balance of beer flavor. The role of HSI in guiding brewers’ decisions to achieve bitterness targets is examined, with particular attention to the sensory impact of oxidized hop acids. Additionally, while HSI is primarily associated with α-acid degradation, its relevance to aroma hops remains a subject of investigation. The relationship between HSI and volatile aroma compounds is evaluated, assessing its potential as a broader indicator of hop freshness and aroma stability.

Kveik is a term used to describe a group of traditional Saccharomyces cerevisiae strains originally employed by regional Norwegian brewers for the production of malt-based beverages and bread. A key feature of kveik strains is that they perform well at elevated temperatures and under high gravity conditions. These traits are believed to be indicative of general stress tolerance, however, empirical data on this subject does not currently exist. In this study, the tolerance of kveik strains to industrial challenges including heat, ethanol, oxidative and osmotic stress was quantitatively determined. The data obtained indicated that kveik yeast showed a remarkable tolerance to stress in general, and high temperature in particular, based on combined analyses of growth kinetics and metabolic activity tests (MTT cytotoxicity assay). Further analysis indicated that trehalose was observed to be elevated in kveik yeasts under both stressed- and non-stressed conditions, suggesting that this stress protectant is a principal factor contributing to tolerance. This data has direct implications for brewing, and broad commercial relevance for the global fermentation industry; the potential for using highly stress-tolerant strains forms a key strategy for sustainable practices through intensification of processes and maximizing efficiencies, leading to reductions in processing times and associated costs.

Malting barley (Hordeum vulgare L.) grain suffers from pre-harvest germination. Large scale damage within the field results in adverse effects influencing viability, storage capacity and quality all induced by untimely weather conditions prior to harvest. This costs the brewing and malting industry bn’s of USD annually. A critical review presents itself discussing the governing factors facilitating pre-harvest germination, such as phytohormones and their role in controlling dormancy. A comparison is made between proposed, current and NIR technology for the detection of pre-harvest germination of cereals, specifically barley, however, for clarity other small grain cereal types are included to justify near infrared technology. Dated methods currently used, hailing from the 1960’s, are considered the industry standard, these include the Hagberg falling number and Rapid Visco Analyser tests. Both methods rely on indirectly detecting α-amylase activity by rheology; however, they fall short to detect early-stage pre-harvest germination. This being the period of germination following imbibition up until circa 16 h of germination, resulting in too low α-amylase activity to be measured conventionally. It is further pointed out how the accuracy, sensitivity, degree of robustness and industry acceptability of any new techniques mostly have failed to address the needs of the malting and beer brewing industry. With further emphasis suggesting that adoption of NIR technology in the malting and brewing sector can lead to significant strides in detection of pre-harvest germination. However, significant work is required to fully utilise the NIR technology in an industrial setting.

Daqu, an essential component in Baijiu production, is classified into low-temperature Daqu, medium-high temperature Daqu, and high-temperature Daqu based on the maximum achievable temperatures during the production process. Medium-high temperature Daqu is used for brewing strong-flavor Baijiu. The low-temperature incubation period, the first stage of indoor cultivation in the production process of medium-high temperature Daqu, is crucial for the growth and reproduction of various brewing microorganisms. This study examined the physicochemical indexes, microbial composition, and volatile compounds during the low-temperature incubation period of Daqu. As the temperature of Daqu increased, the acidity initially rose and then decreased, starch content continued to increase, alcoholic power increased continuously, esterifying power almost doubled and glycosylated amylase decreased. A total of 46 major volatile compounds, including alcohols (14), esters (18), acids (3), furans (1), aldehydes (5), phenols (2), ketones (2), and pyrazines (1), were identified. Phenylethyl alcohol exhibited the highest concentration and the greatest variation. Among them, Lactobacillus and Issatchenkia were identified as the most abundant bacterial and fungal genera, respectively. Trichosporon showed the strongest positive correlation with the increase in butanol content, and Aspergillus exhibited significant positive correlations with many types of important physicochemical indexes of Daqu. Wickerhamomyces, Saccharomyces, and Alternaria disappeared in the later stage of the low-temperature incubation period. These findings provide important evidence for better understanding and optimizing the crucial low-temperature incubation period, ultimately enhancing the quality of Daqu production.

Chinese strong-flavor baijiu brands are categorized into Sichuan, Jianghuai, and Beifang styles based on their regional origins. However, no systematic method exists to identify the different styles. Here, we identified different substances based on trace components and determined the similarities and differences among the different styles. We used multi-solvent liquid–liquid extraction combined with gas chromatography-mass spectrometry to detect trace components in strong-flavor baijiu. Near-infrared spectroscopy combined with three algorithms (extreme learning machine, partial least squares-discriminant analysis, and support vector machine) was used to classify the three styles of strong-flavor baijiu. Twenty-eight substances that may contribute to the individuality and generality of the three baijiu styles were identified. The prediction accuracy of the three models was more than 80%. Near-infrared spectroscopy data combined with chemometrics has great application value for rapidly identifying different baijiu brands. This method also shows potential for use in the authentication of different baijiu styles.

ABSTRACT European and Canadian regulators enforce strict limits on the ethyl carbamate content of alcoholic beverages. North American distillers’ malt have high glycosidic nitrile levels which amplify the ethyl carbamate level of whiskey. Guidelines are required to produce low ethyl carbamate whiskey from North American distillers’ malts. This work challenges several strategies for reducing ethyl carbamate levels in bourbon and American whiskey products. New make spirit was produced using a bourbon mash bill on a continuous beer still with doubler. The low wines alcohol content and beer feed tray were systematically varied while the caustic cleaning schedules were monitored to generate 113 unique high wines distillate samples. Ethyl carbamate levels in each sample were determined by gas chromatography-mass spectrometry. Ethyl carbamate levels are reduced by feeding beer into a lower tray on the distillation column. Ethyl carbamate levels are reduced in distillates collected shortly after caustic cleaning over those collected longer after a caustic cleaning. There was no significant effect (p > 0.05) on ethyl carbamate levels as the low wines alcohol content was changed.

Hops (Humulus lupulus L.), essential in brewing, have traditionally been cultivated in high latitudes due to their short-day photoperiod requirements. Brazil, a major global beer producer, imports nearly all its hops, mainly from the United States and Germany, as it lies outside the ideal hop-growing latitude of 35° to 55°. Recently, Brazil has begun experimenting with hop cultivation, using technologies like LED lighting to manipulate the photoperiod. Climate, soil, and agronomic practices contribute to regional variations in hop quality, influencing chemical composition and sensory profiles. This study investigates the regional identity of Comet hops from Brazil and two U.S. regions, Oregon and Washington, highlighting distinct chemical and sensory characteristics. Brazilian Comet hops showed higher concentrations of alpha acids (13.88%) and total oils (2.64 mg/100 g) compared to U.S. counterparts. Sensory analysis revealed that Washington Comet hops had a more grassy profile, Oregon hops were fruitier, and Brazilian hops were more commonly associated with onion/garlic notes. Multivariate statistical analysis indicated clear clustering by region, confirming distinct regional characteristics. This study enhances the understanding of hop regional identity and provides insights into quality control and geographic indication, laying the foundation for future research into the impact of regional variation on beer flavor.