A vine physiology-based terroir study in the AOC-Lavaux region in Switzerland

AIM: Pinot Noir (PN) wines produced in South Tyrol were profiled with the aim to provide guidelines for the oenologist to reach specific winemaking goals in terms of typicity and quality.

Aims: The aims of this study were: (1) to compute recent-past thermal conditions over European vineyards, using state-of-the art bioclimatic indices: chilling portions and growing degree hours; (2) to compute future changes of these thermal conditions using a large ensemble of high-resolution climate models.

The terroir offers great variability in the typicity of the wines produced. Following tastings integrating several vintages, the multiple factor analysis of the sensory data revealed a group of taste criteria contributing to the notion of “Power”, referenced “Power and Harmony”, which makes it possible to differentiate wines from various terroirs of the Middle Loire Valley (Pages et al ., 1987).

Wineries of Beaumes-de-Venise area make their best red wines with grapes from the “Triassic terroir”. This « terroir » is characterized by soils from the Triassic period. These specific soils are complex and quite heterogeneous. They originate from an eventful geological history to keep in mind to understand soils geographical distribution.

The use of selected cultures of the species Lactiplantibacillus plantarum in Oenology has grown in prominence in recent years. While initial applications of this species centred very much around malolactic fermentation (MLF), there is strong evidence to show that certain strains can be harnessed for their bio-protective effects. Unwanted spontaneous MLF during alcoholic fermentation (AF), driven by rogue Oenococcus oeni, is a winemaking deviation that is very difficult to manage when it occurs. This work set out to determine the efficacy of one particular strain of Lactiplantibacillus plantarum(Viniflora® NoVA™ Protect), against this problem in Cabernet Sauvignon must. The work was carried out at commercial scale and in a winery environment and compared the bio-protective culture with the more traditional approach of reducing must pH by the addition of tartaric acid. The combination of both was also investigated. The concentration of both Oenococcus oeni and Lactiplantibacillus plantarum was determined using qPCR. The adventitious Oenococcus oeni showed the most growth during AF in the control wine, whereas in the wines treated with Lactiplantibacillus plantarum a bacteriostatic effect against this species was observed. This effect was comparable to the wines treated with tartaric acid. This has particular commercial relevance for controlling the flora in musts with high pH, or when the addition of tartaric acid is either not permitted or is prohibitive for other reasons.