High Potential of Pichia kluyveri and Other Pichia Species in Wine Technology

Abstract

The surfaces of grapes are covered by different yeast species that are important in the first stages of the fermentation process. In recent years, non-<i>Saccharomyces</i> yeasts such as <i>Torulaspora delbrueckii</i>, <i>Lachancea thermotolerans</i>, <i>Metschnikowia pulcherrima</i>, and <i>Pichia kluyveri</i> have become popular with regard to winemaking and improved wine quality. For that reason, several manufacturers started to offer commercially available strains of these non-<i>Saccharomyces</i> species. <i>P. kluyveri</i> stands out, mainly due to its contribution to wine aroma, glycerol, ethanol yield, and killer factor. The metabolism of the yeast allows it to increase volatile molecules such as esters and varietal thiols (aroma-active compounds), which increase the quality of specific varietal wines or neutral ones. It is considered a low- or non-fermentative yeast, so subsequent inoculation of a more fermentative yeast such as <i>Saccharomyces cerevisiae</i> is indispensable to achieve a proper fermented alcohol. The impact of <i>P. kluyveri</i> is not limited to the grape wine industry; it has also been successfully employed in beer, cider, durian, and tequila fermentation, among others, acting as a promising tool in those fermentation processes. Although no <i>Pichia</i> species other than <i>P. kluyveri</i> is available in the regular market, several recent scientific studies show interesting improvements in some wine quality parameters such as aroma, polysaccharides, acid management, and color stability. This could motivate yeast manufacturers to develop products based on those species in the near future.