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WINEMAKING following the completion of malolactic fermentation and during each quarterly racking thereafter. According to Baugher, a small dose of sulfur dioxide is 5-10 ppm. For him, the amount of SO2 depends on pH and residual sugar-aldehyde formation produced by any in-barrel springtime fermentation. The cellar crew keeps VA in check with cleanliness, topping up barrels every two or three weeks and racking quarterly to hold molecular SO2 at 0.3 ppm. ���We don���t have any issue completing primary or MLF (malolactic fermentation) with the initial 30-35 ppm given at crush,��� Baugher says. ���The wine doesn���t get another addition of SO2 until primary and MLF are complete.��� ���Typically, VA is about 0.045 g/cL going into barrel for the first time. After racking, with minimal additions of SO2 and frequent topping off of barrels, the final VA of our wine going into bottle is about 0.06-0.075 g/cL. The legal limit is 0.132g/ cL, a level that is going to have a strong pickled fruit character,��� Baugher says. ���We apply less SO2 more often,��� Baugher says. ���High concentrations of SEE US AT UNIFIED, BOOTH #2623 66 W in es & V i ne s JANUARY 20 13 SO2 suppress fruit and proper maturation of the wine in barrel.��� Coming to their senses They may go native, but Ridge vineyard managers and winemakers rely on sophisticated laboratory analyses to keep track of each vintage. Vineyard and winery teams follow a protocol that requires sensory and scientific analyses from bud break to bottling. ���We began to develop a high-tech lab in the 1970s because my partners, all Stanford research scientists, pushed the idea,��� Draper says. ���We thought we should learn as much as we could about the natural process, and we wanted to back up our tastings with lab analysis.��� The cellar team relies on laboratory staff to alert them of problems in the making. ���It���s all based on taste,��� says Ridge lab director Karen Leeds. ���The lab provides critical information, but the winemakers don���t depend on the laboratory to make wine. They use data generated from our analyses to keep their hands off the wine.��� Leeds samples for Brettanomyces in regions of the winery where factors like temperature, humidity and age of the barrel or wine might encourage growth. She collects and analyzes composites from barrels of wine that Baugher and Draper might blend. She measures 4-ethylphenol, ethanol and acetic acid concentrations using high-performance liquid chromatography (HPLC). ���HPLC can detect 4-ethylphenol, an indicator for Brettanomyces, down to 23 ppb,��� a fraction of the sensory threshold. Leeds determines free and molecular sulfur with a UV-visible spectrophotometer, continuously. ���Because the assay is based on pH and color,��� Leeds says, ���it also gives us an indication of the complexity of the wine.��� Every three months, the cellar team racks the wine off the lees and tests it to determine stability. Each quarter, Leeds and Gerald Stone run primary chemistry on individual lots. They measure VA, TA, residual sugar, pH, ethanol and SO2 concentrations. ���We walk a fine line between protecting the wine and risking spoilage,��� Leeds admits. They sample the wine as the cellar team racks it and, if needed, add SO2. ���The perfect concentration is 0.3 ppm molecular SO2,��� Baugher says. ���At that level, Brettanomyces can still grow. But doubling the concentration of molecular SO2 can cause as much damage as a larger population