The Use of Indigenous Yeast to Develop High-Quality Patagonian Wines

Abstract

In young wines, the compounds responsible for wine flavor come from two possible origins: grapes and microorganisms involved in winemaking. Yeasts play the most important role in flavor influence because of their role in conducting the alcoholic fermentation (FA), the key process of winemaking. Ecological studies show that yeast diversity is significantly influenced by geographical and technological features of each particular winegrowing region. Wines from Argentine have achieved high-quality certifications, and particularly, in the Comahue region, wine production is mainly oriented to young red wines varieties, some of which found in this region optimal ecological condition to express all their enological potential. Despite this, the need to satisfy the demands of an increasingly competitive and globalized international market and the consumer demand for new wine styles with the best quality/price ratio imposes the regional productive sector new challenges that require technological innovation. The use of starter cultures developed from indigenous yeast isolated from our region, specially selected for its enological properties, appears as a valuable tool for differentiation, diversification, and quality improvement of wines. In this context, conventional and non-conventional yeasts were isolated and selected over the years and used for vinifications in red grape varieties (Pinot noir and Malbec). Assays were carried out at laboratory and pilot scale, in the 2010-2015 vintages. The experiences developed along the years contribute to a better understanding of the processes involved in the production of improved wines by autochthonous strains, an important practice to develop a more competitive regional wine industry.

Apple bagasse as a substrate for the propagation of Patagonian wine yeast biomass

“…Both strains, isolated from vinifications in Patagonian red varieties, were characterized at the molecular level as indigenous to the region (del Mónaco et al . , ). Yeast cultures stored in glycerol at −20°C were activated in GPY broth (glucose 20 g l −1 , peptone 10 g l −1 , yeast extract 10 g l −1 , pH 5·9) at 28°C for 24 h. After this period, tubes were centrifuged and precipitates were washed and resuspended in sterile distilled water until obtaining a concentration of 2·6 × 10 7 cells per ml.…”

“…In this type of wine, the microbial biota responsible for winemaking has a significant influence on the sensorial quality of the product, in particular on its aroma (Fleet ; del Mónaco et al . ). That is the reason why controlling the yeast biota responsible for conducting the alcoholic fermentation (AF), the central process of winemaking, is key to obtaining regularity in wine quality.…”

“…2014b) and the constitution of an important collection of local Saccharomyces cerevisiae and nonsaccharomyces strains relevant for oenological application and wine starter elaboration (del Mónaco et al . ). Indeed, some of these autochthonous strains belonging to S. cerevisiae and Pichia kudriavzevii species have proven ability to produce quality wines both at laboratory scale (del Mónaco et al .…”

“…2014b) and pilot scale (del Mónaco et al . ). The next step is to develop and commercialize local starter cultures in the form of active dry yeast (ADY) for their application in regional and national wine production.…”

“…In the Comahue Region (northwestern Patagonia), the revival of viticulture resulted in a significant reactivation of the historical productive areas (upper valley of Río Negro) and in the development of new areas with climate and soils suitable for qualified oenological activity (Le Guillou ; del Mónaco et al . ; Rodriguez et al . ).…”