The use of indigenous yeast to develop high quality Patagonian wines

SILVANA MARÍA DEL MÓNACO; SEBASTIÁN MARIO EZEQUIEL BRAVO; RAMONA DEL CARMEN MATURANO; ADRIANA CATALINA CABALLERO; YOLANDA LETICIA CURILÉN; ADRIANA BEATRIZ SIMES

Grape and Wine Biotechnology

Intech

Año: 2016; p. 325 - 344

The chemical composition of wine is thefoundation for its sensorial features. In young wines, like the ones mainlyproduced in the Patagonia Argentina, the compounds responsible wine flavour come from two possible origins:alcoholic fermentation (AF) and malolactic fermentation (MLF), two bioprocessesinvolved in vinification. Although Saccharomycescerevisiae y Oenococcus oeni arethe yeast and LAB species mostly relevant in wine elaboration, other speciesare also able to remain in musts and wines during spontaneous fermentation andcontribute to the sensory quality of the product. Those species variability issignificantly influenced by geographical or/and technological specific factorsin each productive region and important from the enological point of view. Thepractical consequence of studies on microbial ecology in winemaking was thedevelopment of saccharomycetic and non-saccharomycetic starter cultures for AFand cultures for MLF. Within the productive chain, standardization of microbialbiota associated with the alcoholic and malolactic fermentation by means ofusing specific starter cultures is key to producing wines of differential andcontrolled quality. Wines from Argentine have achieved high qualitycertifications (of origin or geographical designations). In the Comahue Region,wine production is mainly oriented to red wines as Pinot Noir and Merlot, that foundin this region an optimal ecological condition to express all their oenologicalpotential. Despite this, the need to satisfy the demands of an increasinglycompetitive and globalized international market actually oversupplied, and theconsumer demand for new wine styles with the best quality/price ratio, imposeto the regional productive sector new challenges that require technological innovation.The use of starter cultures developed from indigenous yeast and LAB strainsisolated from our region, specially selected for its oenological propertiesappears as a valuable tool for differentiation, diversification and quality improvementfor regional wines. In this context, yeast and LAB where isolated and selected over the yearsand 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.Metabolic oenological features were studied and processes were optimized.Yeast-LAB interactions were detected to potentiate their influence in wine, andsensorial traits in the obtained wines where discriminated. Finally, consumerpolls allowed us to validate the products according to the public inclinationsand preferences. The sensory quality of wines made from the indigenous culturesshowed always higher scores than those obtained with the commercial strains.The experiences developed along the years contribute to a better understandingof the processes involved in the production of improved wines by autochthonousstrains, an important practice to develop a more competitive regional wineindustry.