Issue link: http://winesandvines.uberflip.com/i/754815
76 WINES&VINES December 2016 WINEMAKING WINE EAST ery failed to employ any pre-evac- uation treatment. Similar results were found for the critical headspace (HS) evacu- ation practice. However, just five wineries utilized an evacuation technique to remove headspace oxygen. Although several closure types are available to winemakers, synthetic cork was the most popu- lar, with seven wineries utilizing that closure. For the remaining clo- sures, 1+1 (twin tops), screwcaps and natural corks were used by two wineries for each type, and one win- ery used a technical (agglomerated) cork. It is important to keep in mind that the type of closure used may depend on the type or style of wine the winery happened to be bottling the day of the study. Analyses conducted Commercial wines from these 14 Ohio wineries were selected for analysis. For each wine, tempera- ture and dissolved oxygen (DO) measurements were taken at the holding tank. Then, 12 bottles were collected during the middle of the bottling process. Several measurements were taken at various storage times: zero, seven, 21, 63 and 126 days. At each time interval, three bottles were sacrificed for analyses, except at bottling (zero time interval), when only one bottle was examined for sulfur dioxide and pH. The dis- solved oxygen (DO) and headspace (HS) oxygen levels were deter- mined by using PreSens technology with a NomaSense Trace Unit oxy- gen analyzer. For the free and total sulfur dioxide contents, the aera- tion-oxidation method was used. A pH meter, the Accumet-Basic Model AG-15 from Fisher-Scientific, was employed for all pH readings. Also, all results were recorded as aver- ages of three replications. Dissolved oxygen at holding tank and bottling In order to control the dissolved oxygen (DO) level in wines, every effort should be made to avoid oxy- gen enrichment at each step of vinification. If high O 2 values are detected, measures need to be used to correct the winemaking errors. A suggested guideline level for DO at the holding tank, just prior to the filler and bottling, is less than 0.5 ppm. The table "Temperature and Average DO Levels for Wines in Holding Tank and After Bottling" on page 76 summarizes the DO results for all the Ohio wines at the holding tank location. TEMPERATURE AND AVERAGE DO LEVELS FOR WINES IN HOLDING TANK AND AFTER BOTTLING Holding Tank Bottled Wine Winery Temperature (º F) DO Level (ppm) DO Level (ppm) A 64 1.6 1.4 B 54 1.2 2.1 C 64 1.3 1.4 D 69 3.0 3.9 E 71 0.5 1.1 F 72 1.1 1.4 G 71 2.7 3.3 H 71 0.8 2.5 I 71 0.1 0.7 J 68 0.8 1.3 K 58 0.2 0.5 L 68 0.5 1.5 M 71 0.3 1.3 N 60 2.2 3.7 A suggested dissolved oxygen (DO) level prior to bottling is 0.5 ppm.