The role of œnology in the enhancement of terroir expression

The reality of terroir is reflected by the typicality that it confers on the wine. The relationship between the origin of wine and its quality did already exist before the appearance of œnological science. Producers and merchants have always tried to improve wine quality in order to satisfy their clients. Before being scientific, this approach was empirical. Grands Crus emerged in Bordeaux when wine could be aged thanks to the development of techniques like disinfecting barrels with sulphur candles, racking, topping up and bottling with cork stoppers. Pasteur was the founder of the oenological science. He had a scientific, but also very practical approach. In the 1930’s, the application of the knowledge about pH, oxydo-reduction and colloids to wine production improved stabilisation of wines. The principles of modern red wine vinification and control over malolactic fermentation were first established in Bordeaux Grand Crus in the 1950’s-1960’s, before being internationally adopted. In the 1980 the œnological science progressed in the understanding and the control of alcoholic fermentation. Today, the role of nitrogen, lipids, temperature and oxygen are well understood. Knowledge about yeast genetics helped to select yeasts for various styles of wines. Off flavours in wines are better controlled since the molecules that are involved have been identified. Wine typicality is, among other factors, determined by its aromatic profile. Wines aromas can be different than the aromas in the grapes from which the wine was produced. The understanding of white wine aromas progressed over the last years, but a lot of work has still to be done on red wine aromas. Tannin quality is also a field that is not yet well explained by oenological science. Œnology should not lead to produce uniform « fast wines », but help to produce original and typical wines, for the pleasure of the amateurs and the profitability of wine producing and distributing companies.