Bubbles, Foam Formation, Stability and Consumer Perception of Carbonated Drinks: A Review of Current, New and Emerging Technologies for Rapid Assessment and Control

Understanding the tasting of champagne and other sparkling wines from a scientific perspective

From uncorking the bottle to the bursting of bubbles in the glass, the science behind the tasting of champagne and other sparkling wine is both traditional and at the forefront of modern developments. The strong interaction between the various parameters at play in a bottle and in a glass of sparkling wine has been the subject of study for around two decades. Indeed, sparkling wine tasting is often seen as the pinnacle of glamor and frivolity for most people, but it should also be considered as a fantastic playground for chemists and physicists to explore the subtle science behind this centuries-old drink, whose prestige today goes well beyond the borders of Champagne and France. This article offers an overview of the physicochemical processes that mark a tasting of champagne or sparkling wine in the broad sense, from the cork popping out of the bottleneck to the formation and bursting of bubbles in your glass, including the choice of the glass and how to serve and drink the wine correctly.

Formation of pores and bubbles and their impacts on the quality attributes of processed foods: A review

Pores and bubbles significantly influence the physical attributes (like texture, density, and structural integrity), organoleptic properties, and shelf life of processed foods. Hence, the quality of foods and their acceptance by the consumers could be influenced by the properties and prevalence of pores and bubbles within the food structure. Considering the importance of pores, this review aimed to comprehensively discuss the factors and mechanisms involved in the generation of pores and bubbles during the processing of different food products. Moreover, the characteristics and effects of pores on the properties of chocolates, cheeses, cereal-based foods (like cake, puffed grains, and pasta), dried, and fried products were discussed. The impacts of bubbles on the quality of foam-based products, foam creamers, and beverages were also explored. This review concludes that intrinsic factors (like food compositions, initial moisture content, and porosity) and extrinsic factors (like applied technologies, processing, and storage conditions) affect various properties of the pores and bubbles including their number, size, orientation, and distribution. These factors collectively shape the overall structure and quality of processed food products such as density, texture (hardness, cohesiveness, chewiness), and water holding capacity. The desirability or undesirability of pores and their characteristics depends on the type of products; hence, some practical hints were provided to mitigate their adverse effects or to enhance their formation in foods. For example, pores could increase the nutrient digestion and reduce the shelf life of the products by enhancing the risk of fat oxidation and microbial growth. In conclusion, this study provides a valuable resource for food scientists and industry professionals by discussing the effects of pores on food preservation, heat, and mass transfer (including oxygen, moisture, flavors, and nutrients). Understanding the dynamic changes in porosity during processing will be effective in customization of final product quality with desired attributes, ensuring tailored outcomes for specific applications.

Free versus droplet-bound aroma compounds in sparkling beverages

The initial experience of a beverage's flavor after opening the bottle is created by a combination of the gas phase and droplet-bound odorants. However, most studies do not consider this combination, and focus on the odor-active components in the liquid or gas phase, separately. To cover this aspect, a filter from pyrolyzed polyacrylonitrile fiber was packed inside thermal desorption unit liner and used for trapping droplet-bound odorants. Additionally, polydimethylsiloxane coated thin-film was applied for extraction of gas-phase aroma. Following trapping/extraction, the devices were desorbed and compounds were separated using GC-MS. The odorants in commercial sparkling beverages were quantified immediately after opening the bottle to mimic real-life conditions of the consumer's experience of the flavor. The reported results provide a more comprehensive understanding of flavor perception in effervescent drinks by considering both gas and droplet phase.

Probing dissolved CO2(aq) in aqueous solutions for CO2 electroreduction and storage

CO₂ dissolved in aqueous solutions CO₂(aq) is important to CO₂ capture, storage, photo-/electroreduction in the fight against global warming and to CO₂ analysis in drinks. Here, we developed microscale infrared (IR) spectroscopy for in situ dynamic quantitating CO₂(aq). The quantized CO₂(g) rotational state transitions were observed to quench for CO₂(aq), accompanied by increased H₂O IR absorption. An accurate CO₂ molar extinction coefficient ε was derived for in situ CO₂(aq) quantification up to 58 atm. We directly measured CO₂(aq) concentrations in electrolytes under CO₂(g) bubbling and high-pressure conditions with high spectral and time resolutions. In KHCO₃ electrolytes with CO₂(aq) > ~1 M, CO₂ electroreduction (CO₂RR) to formate reached >98% Faradaic efficiencies on copper (Cu₂O/Cu)-based electrocatalyst. Furthermore, CO₂ dissolution/desolvation kinetics showed large hysteresis and ultraslow reversal of CO₂(aq) supersaturation in aqueous systems, with implications to CO₂ capture, storage, and supersaturation phenomena in natural water bodies.

Recent Progress in the Analytical Chemistry of Champagne and Sparkling Wines

The strong interplay between the various parameters at play in a bottle and in a glass of champagne or sparkling wine has been the subject of study for about two decades. After a brief overview of the history of champagne and sparkling wines, this article presents the key steps involved in the traditional method leading to the production of premium modern-day sparkling wines, with a specific focus on quantification of the dissolved CO₂ found in the sealed bottles and in a glass. Moreover, a review of the literature on the various chemical and instrumental approaches used in the analysis of dissolved and gaseous CO₂, effervescence, foam, and volatile organic compounds is reported.

Does the Temperature of the prise de mousse Affect the Effervescence and the Foam of Sparkling Wines?

The persistence of effervescence and foam collar during a Champagne or sparkling wine tasting constitute one, among others, specific consumer preference for these products. Many different factors related to the product or to the tasting conditions might influence their behavior in the glass. However, the underlying factor behind the fizziness of these wines involves a second in-bottle alcoholic fermentation, also well known as the prise de mousse. The aim of this study was to assess whether a low temperature (13 °C) or a high temperature (20 °C) during the in-bottle fermentation might have an impact on the effervescence and the foaming properties (i.e., collar height and bubble size) of three French sparkling wines (a Crémant de Loire and two Champagne wines), under standard tasting conditions. Our results showed that sparkling wines elaborated at 13 °C and served in standard tasting conditions (i.e., 100 mL, 18 °C) had better ability to keep the dissolved CO₂ (between 0.09 and 0.30 g/L) in the liquid phase than those elaborated at 20 °C (with P < 0.05). Most interestingly, we also observed, for the Crémant de Loire and for one Champagne wine, that the lower the temperature of the prise de mousse, the smaller (with P < 0.05) the bubbles in the foam collar throughout the wine tasting.

Complementing Digital Image Analysis and Laser Distance Meter in Beer Foam Stability Determination

The aim of this research is to investigate the possibility of applying a laser distance meter (LDM) as a complementary measurement method to image analysis during beer foam stability monitoring. The basic optical property of foam, i.e., its high reflectivity, is the main reason for using LDM. LDM measurements provide relatively precise information on foam height, even in the presence of lacing, and provide information as to when foam is no longer visible on the surface of the beer. Sixteen different commercially available lager beers were subjected to analysis. A camera and LDM display recorded the foam behavior; the LDM display which was placed close to the monitored beer glass. Measurements obtained by the image analysis of videos provided by the visual camera were comparable to those obtained independently by LDM. However, due to lacing, image analysis could not accurately detect foam disappearance. On the other hand, LDM measurements accurately detected the moment of foam disappearance since the measurements would have significantly higher values due to multiple reflections in the glass.

How Many CO2 Bubbles in a Glass of Beer?

The number of bubbles likely to form in a glass of beer is the result of the fine interplay between dissolved CO₂, tiny particles or glass imperfections acting as bubble nucleation sites, and ascending bubble dynamics. Experimental and theoretical developments about the thermodynamic equilibrium of dissolved and gas-phase carbon dioxide (CO₂) were made relevant to the bottling and service of a commercial lager beer, with 5% alcohol by volume and a concentration of dissolved CO₂ close to 5.5 g L^-1. The critical radius and the subsequent critical concentration of dissolved CO₂ needed to trigger heterogeneous nucleation of CO₂ bubbles from microcrevices once the beer was dispensed in a glass were derived. The subsequent total number of CO₂ bubbles likely to form in a single glass of beer was theoretically approached as a function of the various key parameters under standard tasting conditions. The present results with the lager beer were compared with previous sets of data measured with a standard commercial Champagne wine (with 12.5% alcohol by volume and a concentration of dissolved CO₂ close to 11 g L^-1).

Determination of Foam Stability in Lager Beers Using Digital Image Analysis of Images Obtained Using RGB and 3D Cameras

Foam stability and retention is an important indicator of beer quality and freshness. A full, white head of foam with nicely distributed small bubbles of CO2 is appealing to the consumers and the crown of the production process. However, raw materials, production process, packaging, transportation, and storage have a big impact on foam stability, which marks foam stability monitoring during all these stages, from production to consumer, as very important. Beer foam stability is expressed as a change of foam height over a certain period. This research aimed to monitor the foam stability of lager beers using image analysis methods on two different types of recordings: RGB and depth videos. Sixteen different commercially available lager beers were subjected to analysis. The automated image analysis method based only on the analysis of RGB video images proved to be inapplicable in real conditions due to problems such as reflection of light through glass, autofocus, and beer lacing/clinging, which make it impossible to accurately detect the actual height of the foam. A solution to this problem, representing a unique contribution, was found by introducing the use of a 3D camera in estimating foam stability. According to the results, automated analysis of depth images obtained from a 3D camera proved to be a suitable, objective, repeatable, reliable, and sufficiently sensitive method for measuring foam stability of lager beers. The applied model proved to be suitable for predicting changes in foam retention of lager beers.

Unveiling Carbon Dioxide and Ethanol Diffusion in Carbonated Water-Ethanol Mixtures by Molecular Dynamics Simulations

The diffusion of carbon dioxide (CO2) and ethanol (EtOH) is a fundamental transport process behind the formation and growth of CO2 bubbles in sparkling beverages and the release of organoleptic compounds at the liquid free surface. In the present study, CO2 and EtOH diffusion coefficients are computed from molecular dynamics (MD) simulations and compared with experimental values derived from the Stokes-Einstein (SE) relation on the basis of viscometry experiments and hydrodynamic radii deduced from former nuclear magnetic resonance (NMR) measurements. These diffusion coefficients steadily increase with temperature and decrease as the concentration of ethanol rises. The agreement between theory and experiment is suitable for CO2. Theoretical EtOH diffusion coefficients tend to overestimate slightly experimental values, although the agreement can be improved by changing the hydrodynamic radius used to evaluate experimental diffusion coefficients. This apparent disagreement should not rely on limitations of the MD simulations nor on the approximations made to evaluate theoretical diffusion coefficients. Improvement of the molecular models, as well as additional NMR measurements on sparkling beverages at several temperatures and ethanol concentrations, would help solve this issue.

How Does Gas-Phase CO2 Evolve in the Headspace of Champagne Glasses?

The chemical space perceived by a consumer of champagne or other sparkling wines is progressively modified all along tasting. Real-time monitoring of gas-phase CO₂ concentration was performed, through a CO₂-diode laser sensor, along a two-dimensional array of nine points in the headspace of three types of glasses poured with champagne. Two original glasses with distinct headspace volumes were compared with the standard INAO tasting glass. For each of the three glass types, a kind of temperature-dependent CO₂ fingerprint was revealed and discussed as a function of the glass geometry and headspace volume. Moreover, a simple model was developed, which considers the rate of decrease of the concentration of gas-phase CO₂ in the headspace of a glass after the pouring process as being mainly ruled by natural air convection in ambient air. The timescale which controls the rate of decrease of gas-phase CO₂ was found to highly depend on the ratio of the headspace volume to the open aperture of the glass.

Carbonated Water Droplet Can Ease Dust Mitigation from Hydrophobic Surfaces

Carbonated water droplets can ease the difficulties faced by distilled water droplets mitigating dust particles from hydrophobic surfaces. Rising of CO₂ bubbles in carbonated water droplets and their interaction with the flow structure, created by Marangoni and buoyancy possessions, in droplets are investigated. Spreading and infusion (cloaking) of carbonated water on dust surfaces are analyzed, and the rate at which bubbles formed inside the carbonated water droplet, as placed on a dusty hydrophobic surface, is examined. Flow structures formed inside the carbonated water droplet are simulated, and findings are compared to those corresponding to the distilled water droplet. Dust mitigation from the hydrophobic surface toward droplet liquid inside is evaluated using the high-speed recording system, and the results are compared with those of predictions. It is found that carbonated water spreads and infuses onto dust particles at a higher rate than that at which distilled water does. The rising bubble generates wake-like flow in the fluid while modifying the flow structure inside the droplet; hence, the number of circulating structures increases from two to four in droplet fluid. The dust particles picked up by flow currents are redistributed over the entire carbonated water droplet, while mitigated dust particles remain in the lower region of the distilled water droplet. Bubbles formed inside the carbonated water droplet improve dust lifting and rate of dust mitigation from the surface.

A Digital Approach to Model Quality and Sensory Traits of Beers Fermented under Sonication Based on Chemical Fingerprinting

The development of digital tools based on artificial intelligence can produce affordable and accurate methodologies to assess quality traits and sensory analysis of beers. These new and emerging technologies can also assess new products in a near real-time fashion through virtual simulations before the brewing process. This research was based on the development of specific digital tools (four models) to assess quality traits and sensory profiles of beers produced using sonication and traditional brewing techniques. Results showed that models developed using supervised machine learning (ML) regression algorithms based on near-infrared spectroscopy (NIR) were highly accurate in the estimation of physicochemical parameters (Model 1; R = 0.94; b = 0.91). Outputs from Model 1 were then used as inputs to obtain estimations of the intensity of sensory descriptors (Model 2; R = 0.99; b = 0.98), liking of sensory attributes (Model 3; R = 0.97; b = 0.99), and the classification of fermentation treatments using supervised classification ML algorithms (Model 4; 96% accuracy). These new digital tools can aid craft brewing companies for product development at lower costs and maintain specific quality traits and sensory profiles, creating original styles of beers to get positioned in the market.

Internet of Beer: A Review on Smart Technologies from Mash to Pint

The beer production chain includes some crucial steps regarding processing, delivery, service, and consumption that can benefit from the implementation of IoT (Internet of Things) based technologies. Large breweries implemented the use of sensors and digitization before smaller ones among which are craft breweries. Internet of Beer (IoB) technologies are becoming accessible to mid and small sized brewing companies. Therefore, the objective of this work is to review mainly low-cost IoB smart technologies that can be implemented from the mash to the final product and its service, to improve the brewing production, control, delivery, and final quality increasing profitability. The reviewed applications were retrieved both from the scientific databases and from the web. The work is structured in three macro areas such as beer processing, product logistics and traceability, and service. The results show a future trend characterized by a very fast increase in the use of IoB (also open source) systems to drive efficiency, productivity, quality, and safety. This will be done by real-time monitoring and a data-driven decision support system (DSS). Crucial aspects needing further investigation are data ownership and data standardization. The access price of IoB devices and software is destined for a significant decrease while their diversification on the market will grow leading to a massive future implementation within all the production levels.