Issue link: http://winesandvines.uberflip.com/i/83237
CO VER S T OR Y Must-have The top 10 • Brix levels • Potassium • pH • TA • L-malic acid • Nitrogen NH3 • Tartaric acid • Acetic acid • Glucose + fructose • Phenolic – Flavonoids Contingency analyses • Botrytis panel • Juice yeast and bacteria spoilage panel J.J. +NOPA = YAN Winemakers' views lab analyses W hen it comes to must-have analyses for vineyard, harvest and fermentation, it is not winery size but desired quality and consistency that are most important. I asked several winemakers what they considered to be their basic harvest analy- ses and why—as well as what analyses they use in their contingency plans. The results varied greatly. One winemaker I talked with only utilizes Brix, pH and TA with the occasional YAN, relying on his years of experience and knowledge of the vineyards. At the other end of the spec- trum is a winemaker who collects data as a tool for brand continuity year to year, developing new wine profiles and tuning in the viticulture practices. John Clews, head winemaker at Clos Du QualityStainless_Apr05 3/9/05 11:12 AM Page 1 Val Wine Co. in Napa, Calif., monitors the pH, TA and Brix in grape juice prior to harvest as well as keeping a sharp eye on the vineyards. Acidity levels, seed structure, tannin levels, sugars and the detection of off flavors and aromas such as pyrazines are some elements in evaluating grape maturity. "Berry flavor, including the taste of skin and seed tannins, is the key determinant in deciding when to pick.…One month before picking we start going through the vine- yards weekly, tasting the changing flavors as the berries ripen," Clews said. Clos Du Val's standard juice analysis consists of: Brix, TA, pH, L-malic acid, potassium and YAN. Quality - Value - Experience Quality Stainless Tanks • Professionally crafted • Perfomance guaranteed • Custom designs & features • Quick & competitive pricing • Repairs & modifications • Special application tanks • Stainless winery equipment • Tanks in stock for immediate shipping from 500 to 10,000 gallon capacity Quality Stainless Tanks 510 Caletti Avenue • Windsor, CA 95492 Phone: 707.837.2721 • Fax: 707.837.2733 Toll-Free: 877.598.0672 www.qualitystainless.com winetanks@aol.com FOOD DIAGNOSTICS 28 WINES & VINES OCTOBER 2012 Fabricated Stainless Cooperage Custom strategic capital and expertise for the wine industry www.bacchuswinefund.com (415) 828-8898 bacchuscapital@bacchuswinefund.com must, and we will test for yeast and bacte- rial spoilage organisms if early fermenta- tions are problematic," he said. If Botrytis is evident, "I may order a Botrytis cinerea panel in addition to treating the must for the unwanted fungi and enzymes." The botrytis panel includes Botrytis popula- tions, Laccase and B-glucan. "Potassium, pH—as well as phenolics from berry samples—can be very inac- curate," Clews observed. He blamed berry-to-berry variation, lab extraction techniques and sampling techniques in the vineyard. He said you don't really know what you're looking at until the fruit is at the winery. Although Clews doesn't use phenolic information to make picking de- cisions, he previously had harvest interns testing berries via the Glories Method to obtain and record phenolic maturity. The interns sampled the same block every three to five days and monitored how the anthocyanins and tannins were changing. Clew's contingency plan is for damaged fruit that is detected in the vineyard or at harvest: "More SO2 will be added to the Phenolics assay Corey Beck, director of winemaking and general manager of Francis Coppola Win- COST EFFECTIVE WINE ANALYSIS Test menu includes: Acetic Acid Ammonia Copper Ethanol Konelab Chemwell Benefits: Glucose/ Fructose Lactic Acid Iron Kits compatible with: Vitalab Selectra Cobas Mira Hitachi • Wide test menu available on multiple applications • RX monza analyser requires little maintenance/easy to use • RX monza starter package available • Reduced cost per test T +1 304 728 2890 E enquiries@randoxfooddiagnostics.com www.randoxfooddiagnostics.com Malic Acid Potassium TAS Total SO2