Contribution of grape and oak wood barrels to pyrrole content in wines – Influence of several cooperage parameters

Rotundone accumulation and biosynthesis is a complicated process. Previous research highlighted that these phenomenons were affected under ecophysiological conditions by viticultural practices (e.g. defoliation or irrigation). Individually, these practices often impact several abiotic factors that are difficult to separate such as temperature, water or nitrogen status, or radiation. Such dissociation can be achieved under controlled environmental conditions using potted vines.

Oxidation processes constitute a main problem in winemaking. Oxidation result in color browning and varietal aroma loss, which are key attributes of wine organoleptic quality [1]. Despite the mechanisms involved in wine oxidation have been extensively reviewed [2], the protection of wine against oxidative spoilage remains one of the main goals of winemaking.
SO2 is one of the most efficient wine antioxidants used to prevent oxidation and microbial spoilage. However, intolerances caused by SO2 have led to the reduction of its concentration in wines.

Climate is the major factor influencing the dynamics of the vegetative cycle and can determine the timing of phenological periods. Knowledge of the phenology of varieties, their chronological duration, and thermal requirements, allows not only for the better management of interventions in the vineyard, but also to predict the varieties’ behaviour in a scenario of climate change, giving the wine producer the possibility of selecting the grape varieties that are best adapted to the climatic conditions of a certain terroir. In 2014, Symington Family Estates, Vinhos, established two grape variety libraries in two different places with distinctive climate conditions (Douro Superior, and Cima Corgo), with the commitment of contributing to a deeper agronomic and oenological understanding of some grape varieties, in hot climate conditions. In these research vineyards are represented local varieties that are important in the regional and national viticulture, but also others that have over time been forgotten — as well as five international reference cultivars. From 2017 to 2021, phenological observations have been made three times a week, following a defined protocol, to determine the average dates of budbreak, flowering and veraison. With the climate data of each location, the thermal requirements of each variety and the chronological duration of each phase have been calculated. During maturation, berry samples have been gathered weekly to study the dynamics of sugar accumulation, between other parameters. The data was analysed applying phenological and sugar accumulation models available in literature. The results obtained show significant differences between the varieties over several parameters, from the chronological duration and thermal requirements to complete the various stages of development, to the differences between the two locations, confirming the influence of the climate on phenology and the stages of maturation, in these specific conditions.

The use of hybrids in viticulture is one of the alternatives for sustainable production in hot and rainy regions during grapevine maturation. This sustainable production concerns the reduction of pesticide use, adaptation to climate and control of vine decline. The SR 0.501-17 wine grape hybrid, developed in the grapevine program of the Agronomic Institute of Campinas (IAC), is characterized by producing white grapes with small spherical berries with seeds. The agronomic characterization of this hybrid, especially in different climatic conditions, as well as the evaluation of its performance in winemaking are necessary. The objective of this work was to characterize the duration and thermal requirements of the different phenological stages and the influence of rainfall on the physicochemical characteristics of the must in two contrasting climate regions of the State of São Paulo.

Organic viticulture integrates practices aimed at foresting positive relationships among, vines, soil, and climate, with a focus on sustainability, social responsibility, and environmental protection. To safeguard production integrity, regulatory bodies worldwide conduct organic certifications in accordance with relevant regulations. Considering that agriculture practices influence the nitrogen, carbon and oxygen isotope composition, the study aimed to investigate the response of these isotopes in grape must cultivated by organic, biodynamic and conventional methods to distinguish between production systems.