Microbial formation and modification of flavor and off-flavor compounds in wine

While the colour of wine is important to consumers, it is the aroma and flavour of wine that have the greatest impact and potential for enjoyment. This sensory experience is usually pleasurable; however, it can at times be a less-than-pleasant surprise with off-aromas and off-flavours. Like any tantalizing recipe, the aromas and flavours of red and white wine originate from a blend of ingredients: the grape; yeast and bacterial metabolism during fermentation; wood (when used); and chemical reactions during wine maturation. This chapter covers the pivotal role that yeast and bacterial metabolism have in enhancing wine through their conversion to aroma and flavour active compounds. Considerable recent research has focused on developing microbial starter strains that can enhance desirable characters and reduce or eliminate off-flavours.