Observation and modeling of climate at fine scales in wine-producing areas

Context and purpose of the study. The temperature increase related to ongoing climate changes is causing a progressive anticipation of the ripening time, negatively affecting grape quality at harvest.

Sulphur dioxide (SO2) is a well-established preservative in the wine industry. Its ability to act in different stages of the process as an antioxidant and an antiseptic as main characteristics makes it versatile. However, the need for its reduction or even its replacement has been increasing by the regulatory authorities as well as by the final consumer. To understand the impact of SO2 during ageing on volatile organic compounds (VOCs) and amino acids (AAs) profiles, two white wines (one varietal and one blend) were aged under the same conditions, in the presence of different doses of SO2. After fermentation (t=0), 0, 30, 60, 90 and 120 mg/L of SO2 were applied, wines were kept over lees for 3 months (t=3), then were bottled after 3 (t=6) and 9 (t=12) months.

The assessment of physiological parameters in vineyards can be done by direct measurements or by remote, indirect methods. The latter option frequently yields useful data, and development of methods and techniques that make them possible is worthwhile. One of the parameters most looked for to define the quality status of a vineyard is the degree Brix of its grapes, a quantity usually determined by direct measurement.

2,5-Dimethyl-4-hydroxy-3(2H)-furanone (furaneol) is an important aroma compound in fruits, such as pineapple and strawberry, and is reported to contribute to the strawberry-like note in some wines. Several grapevine species are used in winemaking, and furaneol is one of the characteristic aroma compounds in wines made from American grape (Vitis labrusca) and its hybrid grape, similar to methyl anthranilate. Muscat Bailey A is a hybrid grape variety [V. labrusca (Bailey) x V. vinifera (Muscat Hamburg)], and its wine is one of the most popular in Japan. The inclusion of Muscat Bailey A in the ‘International List of Vine and Varieties and their Synonyms’ managed by the ‘International Organisation of Vine and Wine (OIV)’ in 2013 has further fueled its popularity among winemakers and researchers worldwide.

Soil and climate of 3 vineyards have been characterised in order to determine their influence on grape quality. These vineyards are located in Conca de Barberà (Catalonia, NE Spain) and belong to Cabernet sauvignon and Grenache noir cultivars. All 3 plots are very close, so only interannual climatic data of the nearest meteorological station have been considered.