Issue link: http://winesandvines.uberflip.com/i/116287
WINEGROWING Berry ripening and wine aroma Deloire, Department of Viticulture & Oenology, Stellenbosch University, South Africa BY Alain (present address: NWGIC, Charles Sturt University, Wagga Wagga, Australia) O ptimal maturity of grapes depends on multi-faceted criteria. Several important classes of compounds are biosynthesized during the berry growth period, before and/or after véraison (aromatic precursors, phenolics, hormones, organic acids, etc.), while others are provided by roots and/or leaves (water, minerals, sugar, etc.). Several of these compounds change during the ripening stage of the grape berry. These changes do not occur in a highly coordinated fashion, and instead, suggest a series of independently regulated pathways of synthesis. Each pathway is influenced by seasonal climatic factors, vineyard practices and cultivar. The concept of terroir needs to be considered in relation to harvest and the desired wine style. The concept of terroir needs to be considered in relation to harvest and the desired wine style. The concept of terroir is a complex notion because, apart from climate and soil, it includes people, social organizations and activities such as agricultural practices. Geographical origin is important for products that lay claim to a terroir-linked typicality. Measuring the terroir effect on an agri-food product remains difficult for both trained experts and consumers, for whom the appreciation of the product or lack thereof remains the principal criterion in their evaluation. This does not exclude the ability to recognize the product's properties, but it should be remembered that the perceived taste and aromas will be transformed by the individual's experience into a unique overall sensory impression. 64 p r acti c al w i ne ry & v i ne yard APRIL 20 13 preservation of landscapes and development and encouragement of people are important values that merit current support and advocacy in the future. Optimal grape ripeness is defined according to the wine style goal, which in turn is dictated by market demand or by the objective of producing a wine that respects the expression of a typical terroir-related character. Professionals working within the sector are therefore obliged to accurately characterize the grapes in order to make an informed decision about optimum harvest date, and to adopt fermentation practices to obtain a target wine style. O n e o f t h e m o s t important and difficult parts of a viticulturist and winemaker's job is to predict the wine style from the berries and the enological process. Fruit maturity and wine style It would seem that development of the terroir concept over centuries is a strong indication of its increasing social importance. Terroir-derived food products, the The quality of the grapes is a determining factor in the quality of the finished wine. But how is grape quality itself determined? What are the relevant parameters of the berry that enable the dynamics of ripening to be monitored? One of the most important and difficult parts of a viticulturist and winemaker's job is to predict the wine style from the berries and the enological process. The classical indicators such as Brix, malic and tartaric acids, titratable acidity, tannins, anthocyanins, etc., are strongly related to the perception of the wine's taste (mouth feel). Therefore, it is also highly useful to be able to predict or preSugar per berry Fresh fruit aroma 0 Beginning of veraison 20 25 Days Day 0 = when sugar per berry reaches a plateau Figure 1: Example of Cabernet Sauvignon berry aromatic sequence. Ripe fruit aroma 40 45