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WINEMAKING Going Native, Very Carefully How Ridge Vineyards controls and monitors its all-native fermentations and malolactic conversions By Thomas Ulrich R e-established in time for the 1962 vintage by four engineers from the Stanford Research Institute, Ridge Vineyards remains bound to Old World tradition. The way winemaker and CEO Paul Draper sees it, Ridge produces wine using a process that vineyard managers and winemakers have practiced for thousands of years. ���But we do not follow a simple recipe,��� winemaker Eric Baugher says. ���We���re not on a fixed path except for our commitment to native fermentation.��� During the past half-century, Ridge���s tools have changed, but the importance of terroir (a sense of place) has not. Draper and Baugher guide production with a conveyer belt receiver, whole-berry sorting tables and a well-equipped laboratory, but they still make wine the old-fashioned way. ���We are committed to traditional methods using native yeast and malolactic bacteria without sterile filtration or chemicals other than minimum doses of SO2,��� Draper says. Earthy to elegant Several days of sorting, soaking and fermenting the 2012 harvest have filled the Highlights ��� ative yeast and malolactic fermentations N require less SO2 to control rogue yeast and bacteria. ��� Spontaneous fermentations can yield greater concentrations of aroma and flavor compounds. ��� Native yeast convert more sugar to biomass and end products, reducing the amount of ethanol. 64 W in e s & V i ne s JANUARY 20 13 winery with the aroma of perfectly ripened fruit. The fermentation tanks smell like handfuls of red currants, a sign that native yeast have begun the four-month struggle to convert this year���s vintage from earthy to elegant. ���Three or four days after we pump the freshly crushed and destemmed grapes into open-top fermentors, the yeast cells begin to multiply,��� Baugher explains. ���We want the fermentation to build slowly. Native yeast are good for creating flavors and essential oils, and there���s no need to add nutrients. As the population grows, it recycles resources naturally.��� Musty and mysterious, the freshly fermenting grapes embody the microflora of the winery���s Paso Robles, Santa Cruz Mountain and Sonoma County vineyards. ���We derive character from the soil, climate and genetics of the vine,��� Baugher says. ���Native yeast and malolactic bacteria add another level of complexity.��� The winery team adds 30-35 ppm of SO2 to the must to select for native Saccharomyces and limit the growth of bacteria that could spoil malolactic fermentation. ���Even with high-alcohol yeast (like Saccharomyces), native yeast are able to ferment with ease,��� he says. Baugher is convinced that Saccharomyces originate in the vineyard, not the winery. ���When Lytton Springs opened in 2003,��� Baugher says, ���we tested the new construction and did not find yeast. At Monte Bello, Saccharomyces is not in the air. We find common molds on the microbial plates we place throughout the winery.��� According to Dr. Linda Bisson, professor and geneticist from the Department of Viticulture and Enology at the University of California, Davis, indigenous yeast belonging to the genera Kloeckera, Hanseniaspora and Candida dominate the early stages of fermentation. Pichia drives fermentation when the ethanol concentration reaches 3% to 4%. During the late stages of fermentation, higher temperatures, lower concentrations of sugar and CALIFORNIA Napa Paci���c Ocean San Francisco NV Cupertino Ridge Vineyards Monterey Paso Robles higher concentrations of ethanol favor Saccharomyces cerevisiae and its related CALIFORNIA species S. pastorianus and S. uvarum. Discovering a difference Spontaneous fermentation can produce flavors and aromas that are more complex than must doused with higher concentrations of SO2, then inoculated with commercial yeast. In the July 2005 issue of the Australian Journal of Grape and Wine Research, scientists reported that a mixed culture of Saccharomyces and other native yeast can yield higher concentrations of esters, fusel alcohols and monoterpenoids than must inoculated with Saccharomyces cerevisiae alone. ���With fewer yeast cells present at the beginning of a spontaneous fermentation, native yeast and Saccharomyces convert more sugar to biomass and end products, reducing the amount of ethanol,��� Bisson adds. Together, Saccharomyces and other native yeast yield less ethanol, produce more aroma, enrich flavors, enhance mouthfeel and release enzymes that accelerate a number of chemical reactions. ���We want them to show the nature of the vineyard and enhance the varietal characteristics of the grapes,��� Baugher says. Native yeast can produce aromatic, flavorful, silky wines���the essence of carefully cultivated vineyards and carefully crafted vintages. ���It���s not luck or simply not interfering,��� Draper says. ���It���s paying close attention to the vineyard and the winery.���