Cold Brew Research Articles

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.

Effect of ultraviolet irradiation on the shelf life and chemical composition of cold brew coffee

Dual-frequency countercurrent ultrasonic-assisted extraction of the cold brew coffee and in situ real-time monitoring of extraction process

Study on ultrasound-assisted extraction of cold brew coffee using physicochemical, flavor, and sensory evaluation

The impact of the roasting degree on ultra-high-pressure cold brew (UHP) coffee remains unclear, although it has been found that UHP technology accelerates the extraction of cold brew (CB) coffee. Therefore, this study investigated the effects of three different degrees of roasting (light, medium, and dark) on the physicochemical characteristics, volatile and non-volatile components, and sensory evaluation of UHP coffee. Orthogonal partial least-squares-discriminant analysis (OPLS-DA) and principal component analysis (PCA) were used to assess the effects of different roasting degrees. The results showed that most physicochemical characteristics, including total dissolved solids (TDSs), extraction yield (EY), total titratable acidity (TTA), total sugars (TSs), and total phenolic content (TPC), of UHP coffee were similar to those of conventional CB coffee regardless of the degree of roasting. However, the majority of physicochemical characteristics, non-volatile components, including the antioxidant capacity (measured based on DPPH and ABTS) and melanoidin, caffeine, trigonelline, and CGA contents increased significantly with an increase in roasting degree. The sensory evaluation revealed that as the roasting degree rose, the nutty flavor, astringency, bitterness, body, and aftertaste intensities increased, while floral, fruity, and sourness attributes decreased. The HS-SPME-GC/MS analysis showed that most volatile components increased from light to dark roasting. Moreover, 15 representative differential compounds, including hazelnut pyrazine, linalool, butane-2,3-dione, and 3-methylbutanal, were identified by calculating the odor-active values (OAVs), indicating that these contributed significantly to the odor. The PCA showed that the distance between the three roasting degree samples in UHP coffee was smaller than that in CB coffee. Overall, the effect of roasting degrees on UHP coffee was less than that on CB coffee, which was consistent with the results of physicochemical characteristics, volatile components, and sensory evaluation.

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.

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.

ABSTRACTThis study aimed to identify the best conditions for ultrasonic‐assisted extraction (UAE) of DPPH and phenolic compounds from cold brew coffee using Box‐Behnken Design (BBD) and Response Surface Methodology (RSM). It explored the effects of solid‐liquid ratio (5%–15%), extraction time (40–50 min), and ultrasonic power (70%–80%) on these compounds, finding that all factors significantly influenced the outcomes. Statistical analysis showed the data fit a quadratic polynomial model well, with R2 values of 0.9981 for phenolic compounds and 0.9799 for DPPH radicals. Using 3D surface and contour plots from these models, the optimal extraction conditions for these compounds from cold brew coffee were determined. The highest yields of total phenolic compounds and DPPH radical were obtained when samples were extracted at a 10% solid–liquid ratio, 45 min extraction time, and 75% ultrasonic power. Under these optimal conditions, total phenolic compounds and DPPH radical were 64.10 ± 0.31 gGAE/mL and 61.90 ± 0.14%, respectively, with a maximum caffeine content of 213.13 ± 0.23 mg/L. Gamma irradiation at kGy also reduced cold brew coffee's microbial content. This research may be a new alternative for producing cold brew coffee that will save time and help extend the shelf life.

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

Purpose: This work aimed to conduct chemical characterization, assess antioxidant activity, and quantify phenolic compounds in Amazonian Robusta Coffee beverages prepared using diverse roasting degrees and extraction methods. Theoretical Framework: Coffee is globally consumed and holds substantial importance as a commodity. Its chemical composition and biological activity of coffee are influenced by several factors, such as cultivar, roasting degree and brewing method. Methods: Amazonian Robusta Coffee beverages were prepared using diverse roasting degrees and extraction methods (Hario V60, French press and Cold Brew). Characterization was conducted to physicochemical analysis (color parameters, browning index, pH, Brix and total dissolved solids), total phenolic compounds (Folin-Ciocalteu method) and antioxidant activity (FRAP, DPPH, ABTS+ and ORAC assays). Results and Conclusions: Hario V60 beverage demonstrated the highest levels of total phenolic compounds (+50%) and antioxidant activity (+40%) across all roast levels (p<0.01), with significantly increased concentrations of total dissolved solids and phenolic compounds compared to French Press and Cold Brew. This enhanced extraction efficiency is likely due to greater surface area exposure and the percolation method. In contrast, Cold Brew exhibited higher a*, b* and Browning Index values (p<0.05), indicating more intense colors from prolonged extraction and greater melanoidin solubilization. Research Implications: This work showed the chemical composition and antioxidant activity of Amazonian Robusta coffee beverages and their potential application for sustainable production. Originality/Value: No previous study has assessed the antioxidant potential, phenolic content and physicochemical characterization of Amazonian Robusta coffee beverages.

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

This study aims to determine: the results of the development of grind size and cold brew extraction video tutorials; the feasibility of grind size and cold brew extraction video tutorial materials. The feasibility of grind size and cold brew extraction video tutorial media; and user responses to grind size and cold brew extraction video tutorials. This research method is development-type research. Namely adapted using the 4D development model with only three stages due to the limited time and costs required for research. Validation of this video tutorial involves two material experts and two media experts; the object of research is a video tutorial. Questionnaires were used in data collection consisting of material validation, media, and video tutorial user responses. The data analysis technique was carried out descriptively and quantitatively. The results of the video tutorial that have been made in the form of online links cover the material of coffee brewing techniques with grind size and cold brew extraction; The video tutorial material is considered feasible with an average of 80%. The video tutorial media is very feasible with an average score of 84%, and the junior barista response obtained an average score of 83% with a very good interpretation. This implies that the video tutorial of the research results can be used in training activities on coffee blending techniques with grind size and cold brew extraction.

Cold brew is a method of coffee extraction that uses low temperature, preserving the volatile compounds of coffee. Freeze-drying allows the preservation of coffee features and nutritional value. The aim of this study was to evaluate the effects of different cryoprotectants in cold brew extracts as a basis for freeze-dried coffee production. Thus, the Coffea arabica extracts and the soluble coffee were characterized concerning caffeine content, antioxidant capacity, total phenolic compounds, and antimicrobial activity to verify the potential of this method. The extracts did not show antimicrobial activity with a high soluble solid content. It was observed that the cold extraction methods were efficient regarding the caffeine content, antioxidant capacity, and total phenolic compounds. Freeze-dried coffees also did not show antimicrobial activity, and they maintained the water and humidity activity standards. In general, cryoprotectants displayed an unfavorable influence on the extract and freeze-dried coffee in the analyses performed. The coffee extract without cryoprotectants had a higher antioxidant capacity (88.12%) and content of phenolic compounds (7.74 mg AG/mL of the coffee extract). Only for the analyses of soluble solids, the cryoprotectants mannitol and fructose showed promising results (14.03 °Brix, 14.40 °Brix, 11.33 °Brix, respectively). Thus, for the analyses conducted, the cryoprotectants did not lead to significant advantages for this process.

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.

This research designed and developed an ultrasonic reactor for a fast and on demand production of cold brew coffee, remarkably reducing the brewing time from 24 h to less than 3 min. The technology was engineered by utilizing resonance to induce ultrasonic waves around the walls of the brewing basket of an espresso machine. The sound transmission system comprised a transducer, a horn and a brewing basket. This arrangement transformed the coffee basket into an effective sonoreactor that injected sound waves at multiple points through its walls, thereby generating multiple regions for acoustic cavitation within the reactor. Furthermore, acoustic streaming induced greater mixing and enhanced mass transfer during brewing. The design was accomplished by modeling the transmission of sound, and acoustic cavitation. Brew characterization and chemical composition analysis was performed, considering factors such as pH, acidity, color, and the composition of caffeine, fatty acids, and volatiles. The efficiency of the extraction increased by decreasing the basket loading percentage (BLP). For instance, sonicating at 100 W doubled the extraction yield and caffeine concentration, from 15.05 % to 33.44 % at BLP = 33 %, and from 0.91 mg/mL to 1.84 mg/mL at BLP = 67 %, respectively. The total fatty acids increased from 1.16 mg/mL to 9.20 mg/mL, representing an eightfold increase, at BLP = 33 %. Finally, a sensory analysis was conducted to evaluate appearance, aroma, texture, flavor, and aftertaste, which demonstrated that coffee brewed for 1 and 3 min in the sonoreactor exhibited almost undistinguishable properties compared to a standard 24 h brewing without ultrasound.

Effects of ultrafiltration membrane processing on the metabolic and sensory profiles of coffee extracts

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.

Assessment of the physical stability of cold brew coffee in retorted beverages

Marketing is crucial to the success of an enterprise. This report is to develop a marketing strategy plan for Coca-Cola company, including seven parts: introduction, situation analysis, market segmentation, innovation, resource allocation, conclusion and recommendation. Situational analysis includes macro-environmental factors, such as policy, economy, society and technology; Industry elements like competitors, suppliers and substitutes; Internal factors, such as the strengths and weaknesses of Coca-Cola. Coca-Cola divided the market into different segments and target each segment with suitable products, which including provides Coca Cola range with different varieties for age segment (18-35); Multiple size of bottles target family size segment; Multiple bottles with different materials target income group; Sugar and calories-free drink target health-conscious group; “Christmas Celebration Bottle Bow” target specific occasion - Christmas. In terms of innovation, Coca-Cola launched new products, including Coca-Cola energy, Simply smoothie and Honest cold brew coffee. Moreover, it also developed new packaging material which is KeelClip™ and is going to replace all the plastic packaging from all can multi-packs. In addition, Coca-Cola innovated its service, which is the adding of loyalty scheme to vending machine. Coca-Cola uses financial planning model to determine the budget and other resources that should be allocated to each project, it invested lots of money into Diet coke and new packaging technology. The recommendation for the future development is expanding markets to health and food areas as well as target other age group (50-54) and introduce suitable products.

Roasting is an important process in the formation of coffee flavor characteristics, which determines the quality of coffee and consumer acceptance. However, the influence of roasting degree on the flavor characteristics of cold brew coffee has not been fully described. In the present study, the flavor characteristics of cold brew coffee with different roasting degrees were compared in detail by using chromatographic and electronic sensory approaches, and the flavor changes induced by freeze-drying were investigated. Pyrazine and heterocyclic compounds were the main aroma compounds in coffee, and gradually dominated with the increase of roasting. Pyridine was consistently present in cold brew coffees of different roasting degrees and showed significant gradient of quantity accumulation. Aroma compounds such as pyrazine, linalool and furfuryl acetate were the main contributors to coffee roasting, floral and fruity flavor. Freeze-drying preserved the fruity and floral aromas of medium-roasted cold brew coffee, whereas reducing the bitterness, astringency and acidity properties that are off-putting to consumers. The higher consumer acceptance and enjoyment in medium roast cold brew coffee may be related to its stronger floral and fruity aroma. The aroma profile qualities of freeze-drying processed medium roasted cold brewed coffee were more dominant and more suitable for freeze-drying processing than medium dark roasting. Application of freeze-drying for cold brew coffee will promote the convenience of drinking. The present study provides valuable technical guidance in improving the flavor and quality of cold brew coffee, and also promotes its commercialization process. © 2024 Society of Chemical Industry.