The importance of soil and geology in tasting terroir; a case history from the Willamette valley, Oregon

Every year, viticulture is facing several outbreaks caused by established diseases, such as downy mildew and grey mould, which possess different life cycles and modes of infection. To cope with these different aggressors, grapevine must recognize them and arm itself with an arsenal of defense strategies.
The regulation of secondary metabolites is one of the first reactions of plants upon pathogen challenge. Their rapid biosynthesis can highly contribute to strengthen the defense mechanisms allowing the plant to adapt, defend and survive.

The concept of terroir is defined by a set of natural and human factors. On the slopy vineyards of the Burgundian « Côte », the « Appellations d’Origine Contrôlée (AOC) » spread out according to the slope in their order of quality : « AOC Grand Cru » at the top, « AOC Premier Cru » and « AOC Village » and « Bourgogne » on the piemont. In order to correlate the hierarchy of the vintages with the evolution of the topographic and pedological criteria, two toposequences were studied, in Gevrey Chambertin (« Côte de Nuits ») and Aloxe Corton (« Côte de Beaune »).

Over the last years, the potential use of non-Saccharomyces yeasts to modulate the production of target metabolites of oenological interest has been well recognized. Among non-Saccharomyces yeasts, Starmerella bacillaris (synonym Candida zemplinina) is considered one of the most promising species to satisfy modern market and consumers preferences due to its peculiar characteristic (enhance glycerol and total acidity contents and reduce ethanol production). Mixed fermentations using Starm. bacillaris and Saccharomyces cerevisiae starter cultures represent a way to modulate metabolites of enological interest, taking advantage of the phenotypic specificities of the former and the ability of the latter to complete the alcoholic fermentation. However, the consumption of nutrients by these species and their produced metabolites may inhibit or stimulate the growth (and malolactic activity) of lactic acid bacteria (LAB).

Several factors like vineyard site, climate, grape variety, ripeness, physical health of the grapes and pest management influence the populations of indigenous yeasts on grapes and later on in spontaneous fermentations.

AIM: Wine consumption in the last fifteen years showed a decrease in Europe [1]. New alternatives of wines appeared on the market. Those beverages are obtained by blending wines and fruit juices or flavoring wines with artificial or natural aromas and have medium alcohol content (from 8 to 10.5%) [2]. Recently, an innovative fruit wine has been proposed obtained by co-fermenting grape must and kiwi juice [3] whose potential attractiveness to consumers should be exploited. However, differences in product acceptability and perception, as well as the individuals’ willingness to consume and pay could change in function of subjects socio-demographic characteristics. The target group selected is represented by young adults (18-35 years old) consumption groups.