Winemaking: Microbiology

Wine, as fermented grape juice, has been one of the favourite products and one of the most prestigious one in different cultures. The father of modern biochemistry and microbiology, Louis Pasteur, devoted several years to understand the production of wine and beer, describing beyond any doubt its microbiological nature and already described a succession of microorganisms, later named as yeasts. The traditional methods to detect and quantify different wine microorganisms are based on morphological tests supplemented with several physiological tests. The estimation of microbiological population density and diversity plays an important role in the winemaking process. Plate enumeration counts the colonies formed by different microorganisms on selected media. The changes introduced in this century after the effort to fulfil the human genome made sequencing more accessible and affordable. The microbiota associated with grapes varies constantly in response to grape variety, climatic conditions, viticultural practices, stage of ripening, physical damage and fungicides applied to vineyards.