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Traditional sparkling wines are produced in a two-step sequence of alcoholic fermentations, followed by extended aging which is an influential factor for the final aroma profile. Traditionally, the second fermentation and aging are conducted in bottles over a minimum of 18 months, resulting in an aroma profile which is shaped by oxidative secondary metabolites like aldehydes, acids and fatty acid esters. In this study, a total of 29 traditional commercial sparkling wines from the categories Champagne, Cava, California Champagne, and others (Prosecco and Cremant) were analyzed. The objective was to determine the impact of microbial activity on the stylistic characteristics of traditional sparkling wines and allow winemakers to reproduce the specific fermentation conditions. The results indicate that malolactic fermentation plays an important role in Champagne and some Cavas, but not in the other sparkling wine categories. The metabolic activity of lactic acid bacteria results in an altered acid profile, amino acid utilization, and aroma production. While primary fermentation esters like phenylethyl acetate and isoamyl acetate are significantly reduced in Champagne and Cava, aroma compounds from secondary microbial activity like ethyl lactate and 2-acetyl-1-pyrroline are increased. This underlines the importance of diverse microbial activity of the characteristic style of traditional sparkling wines. [ABSTRACT FROM AUTHOR]

Bentonite is a natural clay that is used in different industries as a desiccant, ion-exchange material, or additive to remove impurities. For example, marketed as healing clay and as protein-fining agent in wine, bentonite is expected to adsorb specific compounds while having no negative effects on the quality of the product in which it is used. In this study, 34 commercially available bentonites for different applications were selected and analyzed for their elemental composition, extraction of heavy metals, swelling behavior, and protein removal rate under conditions relevant to wine. The results indicate that bentonites can have a very variable composition that does not correlate with the intended use. The extraction of heavy metals is not directly related to the raw material and depends on swelling behavior and surface area of the clay. Interestingly, there is a similar degree of variability in swelling behavior among wine bentonites as there is for healing clays. This correlates with the protein removal rate but also with the extraction of iron, a transition metal that is known for its catalytic activity for oxidation reactions. Even though the protein removal rate is much higher than for other clays, bentonites that are marketed for wine show an extraction behavior that can have a negative effect on the final product. [ABSTRACT FROM AUTHOR]

A novel method for the sensory evaluation of wine and cider is proposed that combines advantages of other commonly used techniques while simplifying a tasting protocol that is more accessible for unexperienced panelists. The method is based on panelist’s evaluation of samples in three discrete and directed steps; evaluation of head, heart, and base characters. The technique provides the sensory analyst with a simplified approach to difference testing and, in many instances, helps statistically differentiate samples by reducing panelist confusion. The head aroma is defined as the first impression after removing the lid from a covered glass prior to agitating the sample. The heart aroma is defined as the primary impression after agitating the sample. The base character is defined as the final aroma impression and retronasal evaluation of the product. Each component is evaluated independently using a generalized grouping of descriptors; sensory impression or grouping descriptors can be refined if the analyst aims to draw a higher level of detail or descriptive analysis from their panel. Application of the proposed analytical protocol suggests that the technique is simple for less-experienced panelists to learn and follow, and allowed them to easily focus on the testing attributes with minimal confusion of confounding factors. [ABSTRACT FROM AUTHOR]