pH Control and Aroma Improvement Using the Non-Saccharomyces Lachancea thermotolerans and Hanseniaspora spp. Yeasts to Improve Wine Freshness in Warm Areas

Abstract

Lachancea thermotolerans is a yeast species that works as a powerful bio tool capable of metabolizing grape sugars into lactic acid via lactate dehydrogenase enzymes. The enological impact is an increase in total acidity and a decrease in pH levels (sometimes >0.5 pH units) with a concomitant slight reduction in alcohol (0.2–0.4% vol.), which helps balance freshness in wines from warm areas. In addition, higher levels of molecular SO2 are favored, which helps to decrease SO2 total content and achieve better antioxidant and antimicrobial performance. The simultaneous use with some apiculate yeast species of the genus Hanseniaspora helps to improve the aromatic profile through the production of acetyl esters and, in some cases, terpenes, which makes the wine aroma more complex, enhancing floral and fruity scents and making more complex and fresh wines. Furthermore, many species of Hanseniaspora increase the structure of wines, thus improving their body and palatability. Ternary fermentations with Lachancea thermotolerans and Hanseniaspora spp. sequentially followed by Saccharomyces cerevisiae are a useful bio tool for producing fresher wines from neutral varieties in warm areas.

Multiparametric Approach to Interactions between Saccharomyces cerevisiae and Lachancea thermotolerans during Fermentation

“…effect −7.322). A decrease in this ratio indeed favored the predominance of Lt in the earlier stages of the fermentation, and this species' lactic acid production has previously been shown to occur predominantly at the beginning of fermentation, during exponential growth [2,6,16,54]. This hypothesis was further supported by the pH dynamics shown in Figure 2, in which a rapid pH decrease during the first 72 h can be observed, with this falloff being on average significantly greater for conditions with an Sc/Lt ratio of 0.1.…”

“…For several years, the management of must fermentation to obtain wines with high organoleptic quality has involved the use of Saccharomyces cerevisiae and non-Saccharomyces yeasts. The latter are indeed interesting for use in wine production for several reasons [1]: they increase aromatic diversity [2,3], decrease ethanol concentration [4], induce acidification [5,6], and contribute to biopreservation [7], etc. Nevertheless, cofermentations of S. cerevisiae and non-Saccharomyces yeasts are not yet completely controlled (longer fermentations, variability of product quality, etc.)…”