Résumé
The flagship of the Maison Guigal in the prestigious Châteauneuf-du-Pape appellation, Château de Nalys strives to produce exceptional wines. Since its acquisition in 2017, numerous changes have taken place within the vineyard to enhance the high-potential terroirs. The estate's cuvées are now accustomed to winning awards, although the wines from certain plots can still be perfected in order to be promoted in ways other than in bulk. It is in this context that the experimentation of this master’s thesis is being carried out. The aim of the trial is to improve the quality of a 53-year-old plot of Grenache Noir with high potential but very high yields, by concentrating the grapes and the wines. The gain in quality should enable the wines to be included, at the very least, in the estate's entry-level cuvée. To achieve this, the trial is based on the negative relationship between yield and quality in viticulture. A halving of the yield potential at pruning is tested, with the load per hectare left at pruning varying from simple to double. Data produced in the vineyard, then on the wines and finally during tasting are analyzed statistically on modalities pruned with the usual 2 buds/spur (with and without thinning) and on a modality with 1 bud/spur. The reduction of the yield potential at pruning led to a suspected excess of nitrogen, which caused the opposite effect of what was sought. The wines being less complex, less intense, less colored and less appreciated. Besides this trial, this capricious plot had already undergone unsuccessful trials of grassing, bud thinning and drastic thinning. Uprooting seems to be the last option. Before the development of this experimental part, the appellation, the vineyard and its management, as well as the vinification methods used at the estate are presented.