Brewing Methods Research Articles

Red Rice Alcohol in Southern China: Two Ways of Traditional Brewing and Their Implications for Archaeological Research

ABSTRACT China has a long history of making alcohol using different cereals. Recent archaeological studies demonstrate that people began producing hongqujiu (red rice alcohol) in the early Neolithic. However, because this product is produced and consumed in limited areas today, there is limited information about how it is made. This article reports ethnographic observations of the process of making hongqujiu in two villages in Zhejiang Province, China, where local people practice two different brewing methods–wet and dry. Samples from an abandoned jiugang vat, used in the production of red rice alcohol by a local villager, were studied microscopically to provide reference data on starches, fungi, and other microresidues. By providing reference information on the traditional alcohol-making processes, circumstances of consumption, and morphological changes of starch and fungal elements, this study will improve our understanding of alcohol making and consuming practices in archaeological contexts in China and beyond.

SENSORY PREFERENCE DETERMINATION OF GREEN TEA EXTRACTS FROM UNCONTROLLED AND RELAY-CONTROLLED BREWING PROCESSES USING RANK ORDER CENTROID AND SIMPLE ADDITIVE WEIGHTING

Green tea extract is a popular beverage known for its health benefits. To increase its market appeal, understanding the sensory profiles—taste, aroma, and color—of green tea extract is essential to ensure customer satisfaction. In this study, experiments were conducted to determine the optimal extraction conditions by varying extraction times (3 or 6 minutes) and temperatures (60°C, 80°C, or 100°C) in two brewing methods: (1) a relay-controlled brewing system utilizing Arduino, and (2) a standard brewing process without automated control. Sensory evaluations were conducted by 30 untrained panelists using a 9-point hedonic scale.. Decision-making methods, Rank Order Centroid (ROC) and Simple Additive Weighting (SAW), were then applied to identify the most preferred product. Results indicated that the highest taste score was achieved by the 80°C-6 min sample, while the best aroma and color scores were observed in the 100°C-3 min sample. Overall, the decision-making process using the combination of ROC and SAW methods concluded that the green tea extract from the 100°C-3 min sample was the most preferred by the panelists.

Changes in the total phenolic contents, chlorogenic acid, and caffeine of coffee cups regarding different brewing methods

Coffee is among the most popular beverages consumed worldwide due to its taste, flavor, and alertness effects on drinkers. Besides, caffeine and chlorogenic acid are known as featured compounds of coffee, and there are various phenolic compounds, that demonstrate many benefits for human health. However, the concentrations of those compounds ingested into the human body are greatly dependent on how coffee infusions are prepared. The extraction efficiency of phenolic compounds, caffeine, and chlorogenic acid in the Arabica and Robusta coffee obtained from the light, medium, and dark roasting levels, using the hot brew (at 50°C and 90°C) and cold brew methods was studied. The total phenolic contents (TPCs) were measured by the Folin-Ciocalteu assay, while the first -order derivative spectrophotometry was used to determine the caffeine and chlorogenic acid. Generally, light-roasted Robusta had the highest caffeine (2.10±0.017% w/w), chlorogenic acid (5.63±0.011% w/w), and TPCs (45.5±0.9 mg GAE/g). For brewing experiments, 10 g of coffee was brewed (100 mL of water) for different extraction times. The results show that hot brewing at 90°C was the most efficient method for extracting the TPCs and chlorogenic acid, while cold brewing was better for extracting caffeine. Extraction efficiency increased with longer extraction times, especially for the light roasting level.

How sorghum starch structural properties affect its resistance to cooking in baijiu brewing

The Chinese liquor baijiu is made from fermented sorghum grain. During fermentation, the cooking resistance (starch leaching rate) is an important factor for both baijiu producers and sorghum breeders, to select and breed suitable sorghum varieties. The factors and mechanisms which affect this resistance are not well understood. To investigate this, fifteen brewing sorghum varieties were used for brewing, with sampling over cooking time. The components, starch molecular structure and particle morphology of these samples were characterized and correlated with cooking parameters. In this study, high crystallinity and gelatinization enthalpy in sorghum grains were found to reduce cooking resistance by enhancing swelling power to break the seed coat and cell wall. This is the opposite of what happens in other cereal grains. High protein content, high particle size and high amylose content are the main factors for improving cooking resistance, which occurs by the formation of a cross-linked 3D structure and reduced water absorption to inhibit gelatinization. Both the average and the distribution of chain lengths of amylopectin and amylose are important factors affecting cooking resistance because, among other things, of their influence on crystal structure. This information might help manufacturers select and breed sorghum varieties which have optimal behavior for a given brewing method.

Cafestol and kahweol content in different specialty coffee brews: Exploration by NMR analysis and evaluation of brewing parameters

Cafestol and kahweol, two coffee diterpenes known for their health effects, were quantified in cups of Kenya specialty coffee prepared using eight different brewing methods: AeroPress, Chemex, Clever, V60, Moka, Ibrik, Pure Brew, and French press. High-resolution Nuclear Magnetic Resonance (NMR) spectroscopy was employed for this analysis, involving a straightforward sample preparation procedure with only an extraction step for lipid compounds. Statistical tools were utilized to examine the correlation between diterpene concentrations and each extraction feature, with a focus on the impact of brewing parameters. The results indicate that unfiltered brewing methods produce coffee with high concentrations of diterpenes, whereas paper-filtered methods result in significantly lower concentrations. The findings suggest that these compounds are present in the coffee cup as part of the suspended solids, and that filtration, pressurization, and coffee powder particle size are crucial parameters influencing their concentration.

Influence of varied processing methods on the antioxidant capacity, antibacterial activity, and bioavailability of Iranian black, oolong, and green leafy teas

In this study, the impact of various tea preparation techniques on the content of bioactive compounds, antioxidant capacity, antibacterial properties, and polyphenol bioavailability in green, black, and oolong tea infusions was examined. The findings demonstrated that the fermentation process significantly influences the levels of bioactive compounds, with green tea infusions exhibiting the highest, and black tea the lowest, content of phenolic compounds. A positive correlation was observed between the content of the phenolic compound and both antioxidant and antibacterial activities. Additionally, the microwave brewing method was identified as the most effective preparation technique for maximizing the bioactive compound content and bioavailability. The inclusion of skim milk powder was found to further enhance the bioavailability of phenolic compounds during digestive process. The research suggests that green tea infusions prepared using the microwave brewing method and supplemented with the skim milk powder, could serve as a functional beverage offering enhanced health benefits.

Optimization of the Brewing of “Kablé-Missine”, Togo Northern Local Sorghum Beer

Kablé-missine is a traditional alcoholic beverage predominantly brewed in Northern region of Togo. Despite its widespread consumption and use in various festivities, its quality varies enormously depending on the individual brewing methods. This study aimed to optimize the brewing process of local sorghum beer, kablé-missine, with a particular focus on malting and mashing. Local sorghum grains were subjected to steeping, and key parameters including moisture content during malting, pH, and Brix of the wort were evaluated. The moisture content significantly increased during the steeping phase (39.77 ± 0.44%) and subsequently decreased during germination (37.93 ± 0.53%). The pH of the acidification process was adjusted to 3.11 ± 0.02, and the Brix level significantly increased with extended boiling time in both samples. Moreover, using a limited amount of water during mashing effectively reduced the boiling time.

From Conventional to Craft Beer: Perception, Source, and Production of Beer Color-A Systematic Review and Bibliometric Analysis.

Beer is a popular beverage consumed globally, and studies have emphasized the benefits of moderate consumption as well as its sensory effects on consumers. Color is a crucial sensory attribute, being the first aspect a consumer notices when assessing a beer's quality. This review seeks to offer detailed insights into how brewing methods, raw materials, and the chemical diversity of beer influence the production of beer color. The chemical mechanisms responsible for color development and how consumers and color systems perceive the color of beer were assessed. A systematic review following the PRISMA methodology, coupled with a bibliometric analysis, was performed using (Rayyan 2022) and (VOSviewer 1.6.20) software to assess and evaluate the scientific research retrieved from the Web of Science Core Collection. The findings highlight the significant roles of malt types, heat brewing processes, control of chemical parameters, and innovative brewing techniques in conventional beer color production. Novel chromophores like perlolyrine, pyrrolothiazolate, and furpenthiazinate are thought to affect Pilsen-style beers, along with melanoidins, Strecker aldehydes, and 5-hydroxymethylfurfural (HMF) in conventional beers. In craft beers, such as fruit- or herb-based beers, flavonoids like anthocyanins, along with other natural pigments and synthetic colorants, are identified as the primary sources of color. However, studies related to the influence of chromophores like perlolyrine, pyrrolothiazolate, and furpenthiazinate on beer color are scarce, and emerging additives, such as pigments from microorganisms, spices, exotic herbs, and leaves of plants, on craft beer offer insights for future research.

Trends in Manual Brew Coffee Consumption in Indonesia

This paper aims to examine the trends in manual brew coffee consumption in Indonesia, focusing on consumer preferences, sensory perceptions, and health impacts. Manual brew methods such as V60, tubruk, and cold brew have become popular choices among urban and millennial consumers, as each offers a unique taste and aroma experience. The study employs a literature review and secondary data analysis to explore the factors influencing consumer preferences, including the sensory characteristics and health benefits of manual brew coffee. The findings reveal that brewing methods like V60 produce a more complex flavour profile, while cold brew offers a smoother taste with lower acidity. Additionally, consumer preferences for manual brew coffee are influenced by awareness of the potential health benefits of coffee consumption. These findings are expected to provide new insights for coffee industry players in developing products and marketing strategies that align with consumption trends in Indonesia.

A Comparative Analysis of Cold Brew Coffee Aroma Using the Gas Chromatography-Olfactometry-Mass Spectrometry Technique: Headspace-Solid-Phase Extraction and Headspace Solid-Phase Microextraction Methods for the Extraction of Sensory-Active Compounds.

Coffee, one of the most widely consumed commodities globally, embodies a sensory experience deeply rooted in social, cultural, and hedonic contexts. The cold brew (CB) method, characterized by cold extraction, is a refreshing and unique alternative to traditional coffee. Despite its growing popularity, CB lacks defined preparation parameters and comprehensive analysis of its aromatic composition. In this study, we aimed to obtain a representative extract of the volatile matrix of CB and characterize the aroma of sensory-active compounds using advanced techniques such as headspace-solid-phase Microextraction (HS-SPME) and headspace-solid-phase extraction (HS-SPE) for volatile compound extraction, followed by gas chromatography-olfactometry-mass Spectrometry (GC-O-MS) for compound identification. Optimization of the HS-SPME parameters resulted in the identification of 36 compounds, whereas HS-SPE identified 28 compounds, which included both complementary and similar compounds. In HS-SPME, 15 compounds exhibited sensory activity with descriptors such as floral, caramel, sweet, and almond, whereas seven exhibited sensory activity with descriptors such as chocolate, floral, coffee, and caramel. This comprehensive approach to HS-SPME and HS-SPE aroma extraction with GC-O-MS offers an efficient methodology for characterizing the aroma profile of CB, paving the way for future research and quality standards for this innovative coffee beverage.

Novel continuous cold brewing method for coffee using a combined screw extraction and mechanical expression approach

This study investigated a novel continuous cold brewing method accomplished through a combined countercurrent single-screw extraction process and mechanical expression approach. The effects of four processing parameters (grind size (GS), motor rotation speed (RPM), press cone piston pressure (PCPP), and dry unbrewed coffee grounds feed rate (GFR)) on the particle size of coffee grounds, the mass balance of coffee grounds and water/brew in the brewer, and the physicochemical quality (total dissolved solids (TDS), extraction yield (EY), titratable acidity (TA), total polyphenols (TPP), pH, caffeine and 5-caffeoylquinic (5-CQA) concentration) of the brew were evaluated. The processing parameters significantly affected the mechanical interactions between the coffee grounds and brewer, resulting in changes in the packing density of coffee grounds, the moisture content of the spent coffee grounds, the extent of grind size reduction, and the amount of fines in the brew. These changes affected the physicochemical quality of the resultant brew leading to significant differences in TA, TPP, and 5-CQA, which were positively correlated with TDS.

Factors Influencing Consumer Preferences for Espresso and Omni Roasted Coffee: A Comprehensive Analysis

This qualitative study conducted in Buraydah, Saudi Arabia, explores coffee customers' shifting preferences, with a focus on the growing popularity of espresso and multi-roasted coffee. Through interviews with consumers, baristas, and coffee roasters, the study investigates the motivations behind these choices, which include health concerns, flavor exploration, and a dislike for highly acidic coffees. The findings highlight the appeal of concentrated flavor, higher caffeine concentration, and the ability to appreciate the varied qualities of coffee beans from different places. Omni roasted coffee, with its medium-dark roast, has a balanced flavor profile that works well with a number of brewing methods. The concept of coffee terroir, which highlights the distinct flavors associated with individual origins, influences customer preferences. These findings have ramifications for coffee growers and baristas, who can meet shifting customer needs by acquiring high-quality beans and perfecting brewing procedures. This study leads to a better knowledge of changing coffee preferences and gives practical insights for industry stakeholders.

Comprehensive investigation of coffee acidity on eight different brewing methods through chemical analyses, sensory evaluation and statistical elaboration

Even if the acids composition and their role in coffee still need to be clarified, acidity is one of the main sought-after features in coffee and it is becoming one of the main quality markers. Hence, the aim of this paper was to evaluate the main parameters influencing coffee acidity with a focus on carboxylic acids. To the best of our knowledge, this is the first study regarding filter coffee prepared from specialty and mainstream coffee, differently roasted and through eight diverse extraction methods. Coffee cup chemical composition in terms of organic and chlorogenic acids, caffein and physicochemical parameters were correlated with perceived sourness and mouthfeel to better understand the influence of extracted compounds on the final beverage acidity. Statistical tools revealed that a major impact of chlorogenic acids emerged in pH and titratable acidity, while the sensorial sourness appeared more correlated with organic acids concentration. Thus, these findings suggests that organic acids could be potential predictors of beverage perceived acidity.

Implementation of the Preference Selection Index (PSI) Method in Determining the Best Coffee Shop

The decision support system can be claimed to be a personal computer capable of running data into information so that when taking a semi-structured or problem-specific decision, A coffee shop is a place that prioritizes the sale of coffee with a variety of brewing methods, ranging from cold brew, percolator, Turkish coffee, automatic drip, moka pot, tubruk, Arabica, and many more. In this study, the authors used the PSI (preference selection index) method so that the selection of the best coffee shop was carried out by making a decision matrix, normalizing the decision matrix, calculating the mean value of normalized data, determining the variation of preferences, determining storage in preference values, determining the weight of the criteria, and calculating the PSI value so as to find the best alternative. The criteria used in the selection of coffee shops are five: food, drink, service, entertainment, and parking. Then the final result of the best alternative value is A6 as the best coffee shop in Tanjung Morawa, with a result of 3.702 using the PSI method

Comparative Analysis of Caffeine Content in Cold and Hot Brewed Robusta Coffee Using High-Performance Liquid Chromatography (HPLC)

Coffee is one of the most popular beverages globally, cherished for its unique taste, aroma, and the stimulating effects of its caffeine content. The proliferation of creative coffee shops has introduced various new methods for enjoying coffee, including cold and hot brew techniques. These processing techniques can significantly influence the physicochemical characteristics of coffee, particularly its caffeine content. This study compares the caffeine content in Robusta coffee using cold and hot brewing techniques. The hot brew coffee was prepared using water at approximately 96°C with a French press for six minutes. In contrast, the cold brew method involved brewing with water at room temperature (20-25°C) using a French press, followed by storage for 12 hours in a refrigerator (2-8°C). Qualitative analysis involved examining the color reaction, while quantitative analysis was conducted using High-Performance Liquid Chromatography (HPLC). HPLC is a highly accurate method that is extensively used in the food and pharmaceutical industries. The results indicated that the caffeine content in cold-brewed Robusta coffee was significantly higher, with a concentration of 44.63 μg/mL ± 0.199% and a Relative Standard Deviation (RSD) of 0.4459%. Conversely, hot-brewed coffee showed a caffeine concentration of 23.96 μg/mL ± 0.278%, with an RSD of 1.1602%. The parametric Analysis of Variance (ANOVA) revealed a significance value of 0.000 (p < 0.05), indicating a significant difference in caffeine levels between hot-brewed and cold-brewed coffee. These findings suggest that the choice of Robusta coffee processing technique can be crucial for individuals with specific health conditions seeking to manage their caffeine intake.

Sensory assessment of Gayo Arabica coffee using various cold brew tools

Currently, there is a rapid increase in the cold brew method for coffee, favored by connoisseurs, especially Arabica coffee. This technique uses room temperature water, usually between 4–25°C, and is carried out through the stage of immersing coffee grounds with a coarse grind size in water at an extraction time of 8–24 hours. Therefore, this research aims to conduct a sensory assessment of Gayo Arabica coffee with a cold brew approach to a product with the best taste through a decision-making system using the Fuzzy Simple Additive Weighting (FSAW) method. A total of 5 samples of Gayo Arabica coffee were postharvest processed using the Honey method, which was brewed with various cold brew tools such as Asobu, French Press, Tygo Breeze, Toddy, and Eva Solo. The results showed that the level of product acceptance was different for each alternative product based on various cold brewing tools. The highest ratings of various cold drink alternatives were Asobu 0.974 (rank 1), Toddy 0.913 (rank 2), TygoBreeze 0.872 (rank 3), French Press 0.847 (rank 4), and Eva Solo 0.784 (rank 5). This showed that the FSAW method can easily be used to determine the best alternative for each Gayo Arabica coffee brewing with various cold brew tools.

Comparative study on phenolic compounds of green tea (Camellia sinensis L.) prepared by different brewing methods

Tea consumers’ choices are primarily influenced by taste, aroma, price, and brand while making tea selections; however, they are less likely to consider the phytochemical content and nutritional benefits of tea. Although studies on the phenolic content of green tea under various extraction conditions have been published, to the best of our knowledge, there are no studies on the impact of brewing duration and on the amount of phenolic compounds in the infusion. In this study, the effect of the amount of Turkish green tea (GT, 5-10 g) and brewing time (BT, 5-60 min) on phenolic compounds was evaluated using high-performance liquid chromatography (HPLC). According to the HPLC analysis of green tea infusions, 10 different phenolic compounds were determined: gallic acid (GA, 27.41-78.93 mg/L), gallocatechin (GC, 65.40-307.41 mg/L), catechin (C, 3.81-36.82 mg/L), epicatechin (EC, 177.29-366.71 mg/L), epigallocatechin gallate (EGCG, 645.85-1344.34 mg/L), epicatechin gallate (ECG, 16.60-44.81 mg/L), catechin gallate (CG, 0.245-0.564 mg/L), kaempferol (2.40-10.98 mg/L), quercetin-3-rhamnosylglucoside (Q3RG, 4.89-5.54 mg/L) and an alkaloid: caffeine (CAF, 390.63-785.79 mg/L). In addition, the total catechins and polyphenols were found to be in the range of 1325.00-2798.09 mg/L and 1357.31-2881.08 mg/L, respectively. It was observed that as the amount of green tea brewed increased, the phenolic compounds in the infusion increased in general, but this increase was not linear. There were variations regarding the caffeine and phenolic concentrations, which may be attributed to the brewing time. Therefore, it can be concluded that these compounds are exposed to degradation and/or epimerization as the brewing time increases.

Optimization of Brewing Process Vine Tea and Flavor Analysis of Different Brewing Processes

As a traditional Chinese medicine with the dual use of medicine and food, vine tea has been utilized for centuries as a daily health beverage due to its various health benefits. The primary component responsible for its biological activity is its total flavonoid content. While numerous studies have been conducted on the extracts of vine tea, research has primarily centered on its ingredients and effects, with limited focus on its sensory characteristics. As it has the problems of the undesirable flavor of bitterness and astringency, the development of the vine tea industry is limited. Furthermore, there is currently no standardized brewing process for vine tea. Therefore, it is essential to find a brewing method that is universally applicable and balances a high level of active ingredients with a rich sensory experience. In this study, we conducted a comprehensive investigation into the impact of various water qualities, tea-water ratios, brewing temperatures, steeping times, and frequencies on the total flavonoid content. To investigate the differences between samples from different brewing methods, one-factor experiments (n = 20) and orthogonal experiments were conducted. The total flavonoid content was measured using UV spectrophotometry. To thoroughly examine the flavor compounds, we employed mathematical relationship analysis, radar-gram analysis, principal component analysis (PCA), and odor fingerprinting. By integrating these methods with the electronic tongue and electronic nose, we were able to compare the flavor variances between samples and offer a concise analysis of the flavor compounds. The brewing process is influenced by several factors, with the tea-to-water ratio having the most significant impact, followed by brewing temperature and then brewing time. Electronic tongues and electronic noses can distinguish vine tea samples with different brewing processes to a certain extent. The optimal brewing conditions determined in this study were pure water, a 1 : 50 tea-to-water ratio, an 85°C brewing temperature, an 8-minute brewing time, and a single brew cycle. These conditions produced the highest total flavonoid content in the vine tea, at 326.8 mg/g, and the best flavor quality. This study offers novel approaches to standardize the brewing process of vine tea, along with valuable perspectives for enhancing the sensory attributes of the tea. It can serve as a benchmark for the industry’s future growth in the canning of vine tea, facilitating the creation of diverse vine tea drinks.

Leaves, Infusion, and Grounds-A Three-Stage Assessment of Element Content in Yerba Mate (Ilex paraguariensis) Based on the Dynamic Extraction and Mineralization of Residues.

The more yerba mate infusions that are consumed, the larger the amount of grounds generated. What is more, both the infusion and the residues after brewing remain rich elements. Therefore, a strategy for the three-stage assessment of the element content was presented. A new brewing method was based on dynamic extraction, ensuring both the ease of preparing the infusion and recovering the grounds. In turn, microwave-assisted acid mineralization was used to decompose the leaves and twigs of yerba mate before and after brewing. In total, 30 products were analyzed by ICP OES in three fractions each, i.e., dry yerba mate, infusion, and grounds, to determine up to 25 elements. The elemental composition was considered in terms of the country of origin, type, or composition of yerba mate. The extraction percentages obtained with dynamic extraction were comparable to previously used ultrasound-assisted extraction, as well as data from the literature. The three-stage strategy is a novel approach in yerba mate studies, and it may be a model procedure for the laboratory preparation of yerba mate grounds (waste that can be re-used, e.g., a natural fertilizer).

Uji Sensori Kopi Arabika Pasaman Dengan Menggunakan Metode Seduhan Pour Over V60

Tomi Candra, 2024. "Sensory Quality of coffee using the Pour Over V60 Brewing Method". Final project. D4 Hospitality Management Study Program, Department of Tourism. Faculty of Tourism and Hospitality and Padang State University.
 This research purpose is to analyze the coffee quality using the pour over v60 brewing method in terms of Flavor, Aftertaste, Acidity and Body. As well as knowing the coffee sensory quality using the V60 pour over brewing method and providing information to the public and baristas about the coffee sensory quality using the V60 pour over brewing method. And what is the quality of Pasaman Arabica coffee using the V60 pour over method? This research type include in experiment by making comparisons. The comparison was carried out with 2 comparison aspects and 2 research subjects per comparison aspect, namely grind size and ratio between coffee and water. This research was conducted in the tourism department's barista laboratory on December 1-December 20 2023. The panelists in this research consisted of 3 panelists consisting of 1 tourism department lecturer and 2 expert baristas. Based on the experimental results and after being subjected to organoleptic tests, it was stated that the organoleptic test results after describing the sensory quality of coffee using the pour over v60 brewing method in terms of good flavour, very good aftertaste, quite good acidity and good body.