Investigating the impact of regionality on the sensorial and chemical aging characteristics of Pinot noir grown throughout the U.S. West coast.

The sensorial and chemical differences among Pinot noir wines from different vineyard locations were investigated. Grapes of a single Pinot noir clone were grown on twelve different vineyard sites along the U.S. West Coast. Wines from a single vintage (2015) were made using a standardized protocol and equipment. Sensorial (i.e. aroma, taste, and mouthfeel) and chemical (i.e. polyphenolic and volatile) differences were observed among these wines at two aging time points (8- and 20- months). Vineyard location (i.e. latitude and longitude) was one of the main factors describing the major differences between the wines, while other details (i.e. soil type (60 cm), rootstock age, soil pH, rootstock type, and vines/acres) were possibly important for defining unique aging characteristics of certain vineyards. Overall, single clone Pinot noir grapes grown in different regions but made under standardized winemaking produced wines with unique chemical and sensorial profiles, which generally persisted throughout aging.

Impact of Grapevine Red Blotch Disease on Cabernet Sauvignon and Merlot Wine Composition and Sensory Attributes.

Grapevine red blotch disease (GRBD) is a recently identified viral disease that affects grapevines. GRBD has been shown to impact grapevine physiology and grape composition by altering specific ripening events. However, no studies have been reported on the impact of GRBD on wine composition and its sensory attributes. This study evaluated the impact of GRBD on wine primary and secondary metabolites, in addition to its sensory properties, when making wines from Cabernet Sauvignon and Merlot grapes during two seasons. Wines made with GRBD-impacted fruit were lower in ethanol content when compared to wines made with grapes from healthy grapevines. This was attributed to the lower total soluble sugar (TSS) levels of diseased grapes due to delayed ripening at harvest. GRBD impacted wine phenolic composition by decreasing anthocyanin concentrations and increasing flavonol concentrations in some instances. Additionally, proanthocyanidin concentrations were also consistently higher in GRBD wines compared to wines made from healthy fruit. Descriptive analysis demonstrated that GRBD can impact wine style by altering aroma, flavor, and mouthfeel attributes. However, the extent of GRBD impact on wine composition and sensory properties were site and season dependent.

Evaluation of bitterness in white wine applying descriptive analysis, time-intensity analysis, and temporal dominance of sensations analysis.

Bitterness in wine, especially in white wine, is a complex and sensitive topic as it is a persistent sensation with negative connotation by consumers. However, the molecular base for bitter taste in white wines is still widely unknown yet. At the same time studies dealing with bitterness have to cope with the temporal dynamics of bitter perception. The most common method to describe bitter taste is the static measurement amongst other attributes during a descriptive analysis. A less frequently applied method, the time-intensity analysis, evaluates the temporal gustatory changes focusing on bitterness alone. The most recently developed multidimensional approach of the temporal dominance of sensations method reveals the temporal dominance of bitter taste in relation to other attributes. In order to compare the results comprised with these different sensory methodologies, 13 commercial white wines were evaluated by the same panel. To facilitate a statistical comparison, parameters were extracted from bitterness curves obtained from time-intensity and temporal dominance of sensations analysis and were compared to bitter intensity as well as bitter persistency based on descriptive analysis. Analysis of variance differentiated significantly the wines regarding all measured bitterness parameters obtained from the three sensory techniques. Comparing the information of all sensory parameters by multiple factor analysis and correlation, each technique provided additional valuable information regarding the complex bitter perception in white wine.