Clone performance under different environmental conditions in California

Winegrape cultivars are particularly sensitive to temperature and recent changes in climate have advanced the onset of berry ripening, resulting in unbalanced fruit composition at harvest.

Antagonistic yeasts applied to wine grapes must be compatible with the thereafter winemaking process, avoiding competition with the fermentative Saccharomyces cerevisiae or affecting wine flavour. Therefore, fifteen epiphytic yeasts (6 Metschnikowia sp., 6 Hanseniaspora uvarum, 3 Starmerella bacillaris) previously selected for its biocontrol ability against Alternaria on wine grapes were evaluate for possible competition with S. cerevisiae by the Niche Overlap Index (NOI) employing YNB agar media with 10 mM of 17 different carbonate sources present in wine grapes (proline, asparagine, alanine, glutamic acid, tirosine, arginine, lisine, methionine, glicine, malic acid, tartaric acid, fructose, melibiose, raffinose, rhamnose, sucrose, glucose).

Climate change and rising temperatures present a substantial challenge to viticulture, intensifying summer heat stress and accelerating berry ripening.

In addition to aroma compounds also protein composition strongly influences the quality of wines. Proteins of wine derive mainly from the plant Vitis vinifera and may be influenced by abiotic stress as well as fermentation conditions or fining. Additionally, fungal infections can affect the protein content as well by introducing fungal proteins or affecting grape protein composition. An infection of the vine with the plant pathogenic fungus Botrytis (B.) cinerea was shown to cause a degradation of proteins in the resulting wine. Moreover, it influences the foaming properties in sparkling wine.

The aim of this study was to test how different tank materials could affect the chemical composition and the sensory profile of a red wine during an entire year of aging. For this scope, a single varietal Sangiovese wine was aged, after completing its malolactic fermentation, by using tanks made by different materials. Six thesis were involved in the aging experiment, in particular: stainless