Ancient and recent construction of Terroirs

Late spring frost is a major challenge for various winegrowing regions across the world, its occurrence often leading to important yield losses and/or plant failure. Despite a significant increase in minimum temperatures worldwide, the spatial and temporal evolution of spring frost risk under a warmer climate remains largely uncertain. Recent projections of spring frost risk for viticulture in Europe throughout the 21st century show that its evolution strongly depends on the model approach used to simulate budburst. Furthermore, the frost damage modelling methods used in these projections are usually not assessed through comparison to field observations and/or frost damage reports.
The present study aims at comparing frost risk projections simulated using six spring frost models based on two approaches: a) models considering a fixed damage threshold after the predicted budburst date (e.g BRIN, Smoothed-Utah, Growing Degree Days, Fenovitis) and b) models considering a dynamic frost sensitivity threshold based on the predicted grapevine winter/spring dehardening process (e.g. Ferguson model). The capability of each model to simulate an actual frost event for the Vitis vinifera cv. Chadonnay B was previously assessed by comparing simulated cold thermal stress to reports of events with frost damage in Chablis, the northernmost winegrowing region of Burgundy. Models exhibited scores of κ > 0.65 when reproducing the frost/non-frost damage years and an accuracy ranging from 0.82 to 0.90.
Spring frost risk projections throughout the 21st century were performed for all winegrowing subregions of Bourgogne-Franche-Comté under two CMIP5 concentration pathways (4.5 and 8.5) using statistically downscaled 8×8 km daily air temperature and humidity of 13 climate models. Contrasting results with region-specific spring frost risk trends were observed. Three out of five models show a decrease in the frequency of frost years across the whole study area while the other two show an increase that is more or less pronounced depending on winegrowing subregion. Our findings indicate that the lack of accuracy in grapevine budburst and dehardening models makes climate projections of spring frost risk highly uncertain for grapevine cultivation regions.

Grapevine cultivars can be unequivocally typed by both physical differences (ampelography) and genetic tests. However due to their very similar characteristics, the identification of clones within a cultivar relies on the accurate tracing of supply records to the point of origin. Such records are not always available or reliable, particularly for older accessions. Whole genome sequencing (WGS) provides the most highly detailed methodology for defining grapevine cultivars and more importantly, this can be extended to differentiating clones within those cultivars.

In this audio recording of the IVES science meeting 2022, Florence Fontaine (Université de Reims Champagne Ardenne) speaks about grapevine trunk disease. This presentation is based on an original article accessible for free on OENO One.

Storage temperature and bottling parameters are among the most important factors, which influence the development of wine after bottling. It is well studied that higher storage temperatures speed up chemical reactions and results in faster wine aging [1,2]. It is also known that higher SO2 level and lower oxygen content provide better protection and longer shelf-life for the wine. At the same time, the mechanisms of chemical transformations of wine aromas during the aging process are not fully understood. In particular, how oxidation reactions contribute to the transformations of varietal aroma compounds.In the present study [3], we investigated the development of Riesling wine depending on a series of bottling conditions, which differed in the free SO2 level in wine (low—13 mg/L, medium—24 mg/L, high—36 mg/L), CO2 treatment of the headspace.

If one considers as “physical or sensory attributes” of a wine its concentrations of alcohol and of other substances, it can be stated that another class of attributes exists