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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. Key points: • Flor yeasts were immobilized in microbial biocapsules and used for Sherry winemaking. • Biocapsules decrease ethanol consumption over free flor yeast cells during winemaking. • Use of biocapsules improves Sherry wine organoleptic properties. [ABSTRACT FROM AUTHOR]

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. [Display omitted] • Assess the impact of climate change in a Near Zero Energy Building. • "Cathedral warehouses" will lose their usefulness by the middle of this century. • Comfort limits will be exceeded 19% of the year, interrupting biological ageing. • The economic sustainability of an entire region would be endangered. • The need to evaluate the future behavior of Near Zero Energy Building is highlighted. [ABSTRACT FROM AUTHOR]