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July 2017 WINES&VINES 61 WINE EAST WINEMAKING that tend to uptake lower levels of po- tassium come from the Vitis berlandieri genetic background (Centinari 2016). • After vineyard establishment, reducing vine vigor and foliage shading of grape berries can help reduce potassium up- take and translocation of potassium into the fruit, respectively (Centinari 2016). However, with excessively high potas- sium concentrations in the fruit, these vineyard-management strategies may not be enough to reduce potassium to acceptable levels for winemaking. Research literature (Moss 2016) has recom- mended that growers carefully evaluate both vine and soil potassium levels before proceeding with potassium fertilization. In fact, in an earlier evaluation, it was found that within some soils containing the lowest concentrations of potas- sium surveyed, petiole analysis still resulted in adequate potassium concentrations within the vine (Beasley, Morton and Ambers, 2015). The relationship with potassium uptake in wine grapes is complex. Professional vi- ticulturists can give vineyard owners and managers specific recommendations for vineyard management techniques. However, even with better vineyard selection and management techniques, many winemakers in the eastern United States are facing high- pH fruit and wine challenges, some of which may be contributed by high potassium con- centrations in the fruit. It should be noted that not all high-pH problems are associated with high potassium concentrations, and testing for potassium in vineyards is an im- 251 Gambee Road, Geneva, NY 14456 Phone: 315-759-2118 Toll free: 888-234-6752 Fax: 315-789-1848 Email: cjennings@vancemetal.com Website: www.vancemetal.com Quality Rugged 12 gauge, Custom & Stock Stainless Tanks Catwalk Systems • Pump Over Carts • Custom Hoppers, Chutes & Bins PROUDLY MADE IN THE USA 2015 PENNSYLVANIA CABERNET SAUVIGNON MUST CHEMISTRIES Pre-Fermentation Treatment 2015 Harvest Date pH Adjusted pH TA (g/L tartaric acid) Adjusted TA (g/L tartaric acid) Brix YAN (mg/L Nitrogen) 4 g/L tartaric acid Oct. 15 3.62 2.80 4.95 11.22 20.7° 223 5 g/L tartaric acid Oct. 15 3.62 2.87 4.95 10.14 20.7° 223 Initial pH, TA, Brix and YAN readings were obtained from a single lot of juice prior to dividing into two treat- ments. The pH and titratable acidity (TA) were adjusted pre-fermentation (pre-inoculation) and given at least three hours of settling time before inoculation with ICV-GRE yeast. 2015 PENNSYLVANIA MERLOT MUST CHEMISTRIES Pre-Fermentation Treatment 2015 Harvest Date pH Adjusted pH TA (g/L tartaric acid) Adjusted TA (g/L tartaric acid) Brix YAN (mg/L Nitrogen) 2 g/L tartaric acid Sep. 30 3.88 3.32 4.31 7.93 19.5° 141 4 g/L tartaric acid Sep. 30 3.88 3.05 4.31 11.93 19.5° 141 6 g/L tartaric acid Sep. 30 3.88 3.13 4.31 11.92 19.5° 141 Initial pH, titratable acidity (TA) Brix and YAN readings were obtained from a single lot of juice prior to dividing into three treatments. The pH and TA were adjusted pre-fermentation (pre-inoculation) and given at least three hours of settling time before inoculation with ICV-GRE yeast. Photo at left: The 2013 Chambourcin wine on the left is from Penn State's North East research vineyard and is representative of the hue and intensity as- sociated with the variety in Pennsylvania. The wine at right is from Biglerville research vineyard, which is known to produce high-potassium fruit and wines.