Yeasts associated with the production of distilled alcoholic beverages

Distilled alcoholic beverages are produced firstly by fermenting sugars emanating from cereal starches (in the case of whiskies), sucrose-rich plants (in the case of rums), fructooligosaccharide-rich plants (in the case of tequila) or from fruits (in the case of brandies). Traditionally, such fermentations were conducted in a spontaneous fashion, relying on indigenous microbiota, including wild yeasts. In modern practices, selected strains of Saccharomyces cerevisiae are employed to produce high levels of ethanol together with numerous secondary metabolites (eg. higher alcohols, esters, carbonyls etc.) which greatly influence the final flavour and aroma characteristics of spirits following distillation of the fermented wash. Therefore, distillers, like winemakers, must carefully choose their yeast strain which will be very important in providing the alcohol content and the sensory profiles of spirit beverages. This Chapter discusses yeast and fermentation aspects associated with the production of selected distilled spirits and highlights similarities and differences with the production of wine

Yeasts associated with the production of Mexican alcoholic nondistilled and distilled Agave beverages

The great variety of agaves and their multiple uses have played an important role in the cultural identification of Mexico. They have been exploited in many ways for over 10 000 years, and one of these applications is the production of alcoholic nondistilled and distilled beverages. Most of the production processes of these Mexican beverages involve a complex fermentation in which bacteria (mainly lactic and acetic acid) and yeasts (non-Saccharomyces and Saccharomyces) are present in stable mixed populations, or succeeding one another, and have a significant impact on the sensorial characteristics and nutritive value of the final product. This minireview focuses on several nondistilled and distilled Agave beverages, their production area, the Agave species used in their elaboration, the functional microbiota involved in the fermentation process, their fermentation products (when known), the biochemical changes of these unique fermentations, and their impact on the quality and sensorial characteristics of the product