“Terroir” studies in the Côtes du Rhône controlled appellation: from zoning to application

Bottle ageing is a critical period for wine quality, as it undergoes various chemical and sensory changes during storage. Ideally, a phase of qualitative ageing, during which wine sensory quality improves, is followed by a decline of quality. Understanding how different oenological variables influence these phases is a key challenge in modern winemaking. Recent studies highlighted the significant role of oxygen in modulating reactions involving volatile and non-volatile components, impacting aroma evolution during bottle aging. Oxygen exposure of wine during bottle ageing is mediated by closure.

Climate change and rising atmospheric carbon dioxide concentration is a concern for agriculture, including viticulture. Studies on elevated carbon dioxide have already been on grapevines, mainly taking place in greenhouses using potted plants or using field grown vines under higher CO2 enrichment, i.e. >650 ppm. The VineyardFACE, located at Hochschule Geisenheim University, is an open field Free Air CO2 Enrichment (FACE) experimental set-up designed to study the effects of elevated carbon dioxide using field grown vines (Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon). As the carbon dioxide fumigation started in 2014, the long term effects of elevated carbon dioxide treatment can be investigated on berry ripening parameters and fruit metabolic composition.
The present study aims to investigate the effect on fruit composition under a moderate increase (+20%; eCO2) of carbon dioxide concentration, as predicted for 2050 on both Riesling and Cabernet Sauvignon. Berry composition was determined for primary (sugars, organic acids, amino acids) and secondary metabolites (anthocyanins). Special focus was given on monitoring of berry diameter and ripening rates throughout three growing seasons. Compared to previous results of the early adaptative phase of the vines [1], our results show little effect of eCO2 treatment on primary metabolites composition in berries. However, total anthocyanins concentration in berry skin was lower for eCO2 treatment in 2020, although the ratio between anthocyanins derivatives did not differ.
[1] Wohlfahrt Y., Tittmann S., Schmidt D., Rauhut D., Honermeier B., Stoll M. (2020) The effect of elevated CO2 on berry development and bunch structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon. Applied Science Basel 10: 2486

AIM: Study the chemical and sensory parameters of fifty commercial white wines elaborated with different techniques (fermented in oak barrel and aged on lees (FB+AL); aged on lees (AL); and without aging (WA)) and different grape varieties (Verdejo, Sauvignon blanc and Godello).

The ‘fresh mushroom off-flavour’ has been recognized by the wine industry as an emerging defect since the 2000s. For many years, this off-flavour was not specifically characterized and rather grouped under ‘earthy’ and ‘musty’ taints. However, it has become increasingly problematic due to its rising prevalence. In some vineyards, incidents of this off-flavour now occur as frequently as once every five years. This trend may be associated with climatic changes affecting regions that are more prone to warm and wet seasons.

According to the Protected Designation of Origin (PDO), Cava is protected in the quality sparkling wines made by the traditional Champenoise method were the wine realize a second fermentation inside the own bottle1. Geographical and human peculiarities of each bottle are the main way for the final quality2. The aim of this study is to find correlations and which target compounds are the most representative of the quality of two different grape varieties, Pinot Noir and Xarel·lo. The quality of these two types of grapes is being studied for each variety by a previous classification of the vineyard made by the company who provided the samples (qualities A,B,C,D, being A the better one and D the worst one). The target compounds studied are organic acids and polyphenols. The methodology for the determination of organic acids is HPLC-UV/vis and for some of them the enzymatic methodology.