Sherry Wines Research Articles

Effects of Aging in Wood Casks on Anthocyanins Compositions, Volatile Compounds, Colorimetric Properties, and Sensory Profile of Jerez Vinegars

The Jerez (Sherry) vinegars, including Vinagre de Jerez, Reserva, and Gran Reserva, are crafted from Sherry wines and are protected under the Denomination of Origin in Spain. The aim of this study was to (i) characterize the physicochemical properties and composition; (ii) investigate the impact of the aging process on color properties, phenolics, volatile compounds, and sensorial profiles; and (iii) find a marker for tracing the authenticity of non-aged (Apto) and aged Jerez vinegars. The phenolic components were identified through LC-MS/MS, whereas the volatile compounds were examined using the GC-MS/MS technique. As the aging progressed, a decrease was observed in the levels of flavonol and phenolic acids, with anthocyanin components being undetectable in non-aged and aged samples. In the Gran Reserva variety, 2-methylbutyl acetate, acetic acid, and ethanol emerged as the predominant volatile substances. The presence of oaklactone and ethyl butanoate components served as marker substances to authenticate the Gran Reserva. Additionally, alterations in color properties were noted, marked by a decrease in yellow content and an increase in the red component depending on aging. Furthermore, novel sensory descriptors, such as vanilla, clove, woody, and nutty notes, and winy character emerged in the samples with prolonged aging.

Emotional response to sherry wines and its relationship with emotional intelligence, level of expertise and gender

Emotional elicitation during wine consumption is a complex fenomena based on subjective experience and influence by physiological, cognitive and behavioural changes. The present study used a quasi-experimental design to examine consumers’ emotional responses during blind tastings of sherry wines, considering variables such as consumer experience, gender and Emotional Intelligence (EI). 66 participants were classified as non-expert (34) and expert (32) consumers to participate in blind tastings. Their emotional responses were measured using the EsSense25 Scale and the Perceived Emotional Intelligence was assessed through the Trait Meta-Mood Scale. Few differences were observed on emotional elicitation based on gender or consumer experience (non-expert vs expert), however the interaction of these variables was a good predictor of emotional response variance. Wine type also has an effect on emotional response, emphasising the role of sherry wine characteristics in consumer emotions. Furthermore, the Emotional Attention, one of the three dimensions of Emotional Intelligence, was found as a good predictor for the emotional responses to wine consumption. This relationship may be a key factor in understanding the differences between responsible consumption and excessive consumption, as indicated by research focused on binge drinking.

Influence of flor yeast starters on volatile and nitrogen compounds during a controlled biological aging

Fino Sherry wine undergoes biological aging carried out by a velum of flor yeast within a traditional dynamic system known as “criaderas and solera”. The complex microbiota of biofilm-forming Saccharomyces cerevisiae strains play a crucial role in shaping the distinctive organoleptic profile of these types of wines. For this reason, the aim of this study is to analyze the changes produced by different flor yeast strains in the volatilome and the aminogram of different wines from the criaderas and solera system during biological aging in the laboratory, simulating a flor yeast velum condition at different stages of the system. Results suggest that each strain metabolizes wine differently, finding that depending on the wine, some strains are better suited for the process than others. In addition, it is found that the content of biogenic amines in Fino Sherry wines, previously attributed to malolactic bacteria, varies according to the yeast strain metabolizing the wine, suggesting that flor yeast could be used to modify biogenic amines content during biological aging. Results indicate that the use of selected flor yeast starters in biological aging may be of interest to modulate some parameters during Fino Sherry wine aging.

Influence of the type of Sherry wine and the length of time of the seasoning on phenolic and furanic compounds and CIEL*a*b* parameters of Brandies de Jerez

Brandy de Jerez is a unique spirit characterized by its aging in Sherry Casks®. Seasoning softens the casks’ wood and removes part of its extractable compounds, some of which are undesirable from an organoleptic point of view. The seasoning wine contributes with specific compounds that otherwise either would not be present at all in Brandies de Jerez, or they would in lower quantities. The length of time and the type of Sherry wine are two key parameters to be controlled when considering the seasoning process. In this study, a number of Brandies de Jerez have been aged in casks that were previously seasoned for 3, 6, 12, 18 or 60 months using either one out of three different Sherry wine types or a young fortified wine. It has been demonstrated that, according to the seasoning time and the type of wine used, significant variations with regard to phenolic and furanic compounds and CIEL*a*b* parameters would be detected between the brandies aged in the different casks.

Corrections to “An Electronic Barrel Bung to Wirelessly Monitor the Biological Aging Process of Fino Sherry Wine”

Corrections to “An Electronic Barrel Bung to Wirelessly Monitor the Biological Aging Process of Fino Sherry Wine”

An Electronic Barrel Bung to Wirelessly Monitor the Biological Aging Process of Fino Sherry Wine

An Electronic Barrel Bung to Wirelessly Monitor the Biological Aging Process of Fino Sherry Wine

FT-Raman Methodology Applied to Study the Effect of Time and Type of Seasoning in the Crafting of Sherry Casks® Used in the Aging of Brandy De Jerez.

Brandy de Jerez is a grape-derived spirit produced in Southern Spain with specific characteristics that come from the casks where it is produced, which must have previously contained some type of Sherry wine for at least 12 months. These casks are known as Sherry Cask®. In this work, Brandies de Jerez aged for different aging times (0, 3, 6 and 12 months) in casks seasoned with three different types of Sherry wines (Fino, Oloroso and Amontillado) have been studied. The samples have been analyzed using FT-Raman spectroscopy, and their chemical characterization has also been realized by studying their total content of organic acid, volatile compounds, and phenolic and furanic compounds. Their chemical study showed that the main differences between the studied samples were due to the duration and the type of seasoning performed. However, the spectra obtained through FT-Raman presented noticeable differences according to cask seasoning time and the Sherry wine used for the process. A PCA (Principal Component Analysis) confirmed that the Brandies de Jerez presented significant differences depending on the seasoning time and type that the casks were subjected to. A PLS-R (Partial Least Squares Regression) study enabled establishing a close correlation between specific regions of the FT-Raman spectra and cask seasoning time.

Evolved Saccharomyces cerevisiae strains to reduce ethyl carbamate in Sherry wines

Evolved Saccharomyces cerevisiae strains to reduce ethyl carbamate in Sherry wines

Influence of the type of Sherry wine and the seasoning length of time on the organic acids, volatile compounds, and sensory profile of Brandy de Jerez

Brandy de Jerez is a spirit produced in southern Spain and is characterized by its aging in casks that have previously contained Sherry wine, called Sherry Casks®. The seasoning process is responsible for the presence of compounds from Sherry wines in Brandy de Jerez. Neither the duration nor the type of seasoning have been thoroughly studied. A complete analytical characterization of Brandies de Jerez aged in Sherry Casks® seasoned for 3, 6, 12, 18 and 60 months with Fino, Oloroso and Pedro Ximénez Sherry wines has been conducted. A chemometric study carried out with all the analyzed compounds has demonstrated significant differences between the brandies, depending on the type and the duration of the seasoning of their aging casks. These differences become greater with longer seasoning periods. It has been concluded that 3–6 months of seasoning are not enough for the wine’s contribution to be significant, as some compounds are only detectable after 12 months of seasoning. No significant differences were found between 12 and 18 months of seasoning. When 60 months of seasoning was used, significant contributions and differences could be observed. These results were corroborated through sensory evaluations of the brandies.

Wine Attitude Scale for Consumer Research (WASCR): Scale Development and Validation in Spanish Population

Wine is a fundamental cultural and economic asset for Spain and other European’s countries. Understanding the consumer behavior is of great importance in designing marketing strategies to promote and encourage a product purchase. This research proposes developing and validating an attitudinal scale of the consumer outlook toward wine consumption. A total of 2,189 participants from the Sherry wine region (Andalusia, Spain) participated in the study. A resulting 16-item scale was estimated to meet the reliability criteria and the Principal Component Analysis after exploring the results. Three dimensions were found: one that integrate consumer experiences (Wine Experience), the elements related to the healthy perception of wine consumption (Health Consumption) and those related to factors linked to the social nature of wine consumption (Social Consumption). The Wine Attitude Scale for Consumer Research (WASCR) it has potential use for segmenting different consumer profiles and to be useful tool for wine producers. Therefore, the scale is proposed for use in different research contexts and other populations of interest in future studies.

Effect of the alcoholic strength of unaged wine distillates on the final composition of Brandy de Jerez aged in Sherry Casks®

Brandy is a spirit obtained from distilled wine that has an alcohol content equal to or greater than 36 % ABV (Alcohol by Volume). It undergoes an ageing process in oak wood casks with a capacity of up to 1000 L for a minimum of six months. During this process, a series of physicochemical and sensory changes take place that confer the initial wine distillate with a series of improvements to its sensory profile. Such changes are mainly determined by the intrinsic characteristics of the wood and by those associated with the manufacturing process of the casks. The previous use of the casks, ageing time and the alcoholic strength of the wine distillate are also important factors, among others. The casks, which will have previously contained some type of Sherry wine (such as Fino, Amontillado, Oloroso and Pedro Ximénez), are known as Sherry Casks® and they must be used in the production of Brandy de Jerez. During the ageing of Brandy de Jerez, Sherry Casks® contribute to the final brandy via the compounds that are both inherent to the wood they are made of and from the wine that they initially contained and that were retained in the wood pores. The alcohol content of the wine distillate to be aged significantly affects not only the quality of the brandy, but also the financial cost of the process. This study aimed to determine the influence on brandy of the alcoholic strength of wine distillates aged in static ageing systems using Sherry Casks®. Specifically, we assessed the physicochemical composition and sensory profile of Brandy de Jerez made from wine distillates with three different alcoholic strengths (40 %, 55 % and 68 % ABV) and aged for 24 months. The Brandy de Jerez with lower alcoholic strengths (40 % - 55 % ABV) were found to contain a higher concentration of polyphenolic compounds deriving from the wood as well as from the constituents of the cask-seasoning Sherry wine. The brandies with higher alcoholic strengths exhibited a marked colour change, while the 40 % and 55 % ABV brandies were perceived to have the best sensory characteristics.

Microbial diversity in sherry wine biofilms and surrounding mites

Sherry wines are film wines produced in the Jerez-Xérès-Sherry and Montilla-Moriles regions in southern Spain which require an aging process under flor biofilms, known as “biological aging”. The presence of mites in Sherry wine wineries has been reported and associated with improved wine volatile properties. This work analyzes the microbial diversity in flor biofilms and mites in Sherry wine wineries using Matrix-Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) and ITS/gene amplification. Two mite species, Carpoglyphus lactis and Tyrophagus putrescentiae, were spotted in the sampled winery and 32 microorganism species were identified in their exoskeleton or surrounding biofilms. To our knowledge, 26 of these species were never described before in sherry wine environments. We hypothesized that mites feed on the flor biofilms as well as another type of biofilm located in barrel cracks, known by winemakers as “natas” (cream in English). These non-studied biofilms showed the highest microbiome diversity among all samples (followed by C. lactis spotted nearby) thus, representing a niche of microorganisms with potential biotechnological interest. Besides mites, Drosophila flies were spotted in the sampling areas. The role of flies and mites as vectors that transport microorganisms among different niches (i.e., flor biofilms and natas) is discussed.

Flor yeast immobilization in microbial biocapsules for Sherry wine production: microvinification approach

Sherry wine is a pale-yellowish dry wine produced in Southern-Spain which features are mainly due to biological aging when the metabolism of biofilm-forming yeasts (flor yeasts) consumes ethanol (and other non-fermentable carbon sources) from a previous alcoholic fermentation, and produces volatile compounds such as acetaldehyde. To start aging and maintain the wine stability, a high alcohol content is required, which is achieved by the previous fermentation or by adding ethanol (fortification). Here, an alternative method is proposed which aims to produce a more economic, distinctive Sherry wine without fortification. For this, a flor yeast has been pre-acclimatized to glycerol consumption against ethanol, and later confined in a fungal-based immobilization system known as “microbial biocapsules”, to facilitate its inoculum. Once aged, the wines produced using biocapsules and free yeasts (the conventional method) exhibited chemical differences in terms of acidity and volatile concentrations. These differences were evaluated positively by a sensory panel. Pre-acclimatization of flor yeasts to glycerol consumption was not successful but when cells were immobilized in fungal pellets, ethanol consumption was lower. We believe that immobilization of flor yeasts in microbial biocapsules is an economic technique that can be used to produce high quality differentiated Sherry wines.

Yeast cell vacuum infusion into fungal pellets as a novel cell encapsulation methodology

Immobilized yeast cells are used industrially in winemaking processes such as sparkling wine and Sherry wine production. Here, a novel approach has been explored for the infusion and immobilization of yeast cells into filamentous fungal pellets, which serve as a porous natural material. This was accomplished through vacuum application to force the yeast cells towards the core of the fungal pellets followed by culture in YPD medium to promote their growth from the interior. This method represents an improved variation of a previous approach for the assembly of “yeast biocapsules,” which entailed the co-culture of both fungal and yeast cells in the same medium. A comparison was made between both techniques in terms of biocapsule productivity, cell retention capacity, and cell biological activity through an alcoholic fermentation of a grape must. The results indicated a substantial increase in biocapsule productivity (37.40-fold), higher cell retention within the biocapsules (threefold), and reduction in cell leakage during fermentation (twofold). Although the majority of the chemical and sensory variables measured in the produced wine did not exhibit notable differences from those produced utilizing suspended yeast cells (conventional method), some differences (such as herbaceous and toasted smells, acidity, bitterness, and persistence) were perceived and wines positively evaluated by the sensory panel. As the immobilized cells remain functional and the encapsulation technique can be expanded to other microorganisms, it creates potential for additional industrial uses like biofuel, health applications, microbe encapsulation and delivery, bioremediation, and pharmacy.Key points• New approach improves biocapsule productivity and cell retention.• Immobilized yeast remains functional in fermentation.• Wine made with immobilized yeast had positive sensory differences.

Determining the impact of seasoning on the volatile chemical composition of the oak wood of different Sherry Casks® by DTD–GC–MS

The casks that have contained for a certain time Sherry wines are known as Sherry Casks® and their use and value have increased in recent years, as they confer unique organoleptic properties to the distillates and beverages that are aged inside them. During their seasoning, these casks yield certain compounds from wood into the wines, and at the same time, they retain some compounds from these Sherry wines which, in turn, are transferred to the distillates that are aged inside the casks, so that wood acts as a transfer vector between the two alcoholic beverages. A characterization of seasoned staves with three Sherry wines, Fino, Oloroso, and Pedro Ximénez, by DTD–GC–MS has been carried out in this study. Different tendencies regarding the compounds present in the wood have been observed as follows: in general, certain compounds from wood either disappeared or decreased during its seasoning, while other compounds that come from the seasoning wine either increased or appeared in the wood during the seasoning process. This fact demonstrates that during the ageing of Sherry wines these transfer certain interesting compounds into the casks wood, which are in turn transferred to the distillates.

Microbial Dynamics in Sour–Sweet Wine Vinegar: Impacts on Chemical and Sensory Composition

The most known and traditional vinegar is the one that is made from wine. For its production, the grape must undergo alcohol fermentation and the posterior oxidation of ethanol to acetic acid. Yeasts and acetic acid bacteria (AAB) carry out the biochemical processes in sequence. The process of wine acetification can be achieved by slow traditional processes (the Orléans or French methods) or by a quick submerged industrial process. High-quality vinegar is usually produced by traditional methods using oak casks, once the wood allows the continuous aeration of the acetic bacteria culture. Sour–sweet vinegar presents a balance of both bitter/sour and sweet flavors. The sourness typically comes from acetic acid, while the sweetness can come from the type of fruit or the amount of sugar present at the end of vinegar production. In general, sour-sweet vinegar has a more complex and nuanced flavor profile compared to regular vinegar, which is often simply sour. One kind of vinegar produced by wine acetification where yeasts and bacteria co-exist and produce savory vinegar is traditional balsamic vinegar (TBV), from Italy. In Spain, fortified sherry wine has also been used for vinegar production. In Portugal, some wine companies have produced port wine vinegar since 2018. These three distinctive vinegar products have in common the sweetness that can be found, well balanced with the acetic acid sourness. In this review, we analyze the sour-sweat wine vinegar process, bearing in mind the possible interactions between yeasts and AAB that occur during vinegar production and considering the symbiotic or competitive features of a diverse microbiota.

Improvement of fermentative yeasts S. cerevisiae by Non-GMO strategies for the reduction of urethanes in Sherry wines

During alcoholic fermentation, the yeasts responsible for the process produce various metabolites, including urea. The reaction of urea with ethanol spontaneously generates ethyl carbamate in wine, a carcinogenic metabolite whose concentration needs to be regulated. Yeasts produce urea during the arginine metabolic pathway. For this purpose, adaptive evolution has been used by using a toxic analogue of l-arginine, l-canavanine, for selective pressure, once increasing the genetic variability of the population by sporulation and subsequent conjugation. Using this strategy, five putative variants of the parental yeast have been obtained and seem to have reduced urea production, thus being able to achieve a lower concentration of ethyl carbamate.

Winegrowing strategies for adapting to climate change in a warm climate zone

Climate predictions and simulations forecast that climate change will be one of the major challenges for wine production in the future, as grape quality and vine yields depend on interactions between temperature, water availability, plant material and viticultural techniques employed. Climate change is leading to earlier harvesting, accelerated vine growth and grape over-ripening, leading to the production of grape musts with higher potential alcohol content, higher pH, lower acidity and severe nutritional deficiencies. In order to mitigate these effects, it is necessary to establish short-term viticultural or oenological strategies to minimise the effects of global warming on current wine-growing regions. Therefore, this work presents research results related to the potential of autochthonous grape cultivars from a warm climate area, which could be better adapted to the agro-climatic conditions associated with climate change; as well as the results of the application and recovery of ancestral oenological techniques in the area of sherry wine production (sun-drying and skin contact fermentation), which could contribute to this new climatic scenario as an alternative in wine production.

Analytical, Chemometric and Sensorial Characterization of Oloroso and Palo Cortado Sherries during Their Ageing in the Criaderas y Solera System.

Oloroso and Palo Cortado are two types of sherry wines, produced in the Sherry Wine Region in Southern Spain, known as Marco de Jerez, where it is aged following the traditional Criaderas y Solera system. All of them are aged through oxidative ageing, even though the peculiar Palo Cortado Sherry wine is also aged biologically under a veil of flor yeasts in the first stage. Total dry extract, organic acids, aldehydes, esters, higher alcohols and phenolic compounds in these sherry wines evolve during their ageing as a consequence of evaporation and/or perspiration processes, chemical reactions, extraction of compounds from oakwood and microbiological activity. Sherry wines develop their characteristic organoleptic profile during their ageing, as could be proven through their tasting sessions. According to the sherry type, some natural groupings of the wines could be observed after their principal component analysis. Furthermore, by multiple linear regression methods, an important correlation between the parameters that were analyzed and the ageing of each specific wine has been confirmed, which allowed us to establish two different models, each corresponding to the sherry type in question. Only five of the variables that were investigated were required to successfully estimate each wine's age at over 99% confidence. This represents a rather convenient tool for wineries to monitor the ageing of these sherry wines.

Impact of climate change on sustainable production of sherry wine in nearly-zero energy buildings

Wine is the main economic resource in the ‘Area of Jerez’, located in the south of Spain. It is one of the most important wine tourism destinations in the world. However, its sustainable production process, so strongly influenced by climatic conditions, can be clearly affected by the phenomenon of global warming. The ageing process of “Sherry wine” takes place in buildings known as ‘Cathedral warehouses’, an example of Nearly-Zero Energy Buildings (NZEBs). For centuries, they have been used to provide specific ecological conditions for biological ageing without any type of mechanical heating/cooling system. The purpose of this paper is to assess the impact of climate change on this production model. For this, the annual thermal behavior of a representative winery was monitored during several years. The first energy simulation model of this type of buildings was developed and validated (daily R2 = 99%; hourly R2 = 97%). Finally, the model was simulated by modifying the outdoor climatic conditions (9 years training data sets) for a climate change scenario, applying the ‘morphing’ method for the transformation of the weather data. The results show that, by the middle of this century, the average outdoor temperature will increase by 2.3 °C (in summer up to 3.6 °C). As a consequence, the temperature in the ageing zone would exceed the comfort limit for 19% of the year, (up to 34% in hot years). For 2080, the prediction is even worse (average value of 27%). As a result, the microorganisms responsible for this unique process could not maintain their activity. This fact will force the sector to face a harsh reconversion through the adoption of new mechanisms and strategies, which endangers the economic sustainability of an entire region dedicated to this practice. Beyond the specific case, the work highlights the need to evaluate the future behavior of NZEBs through simulation.