Issue link: http://winesandvines.uberflip.com/i/629061
78 WINES&VINES February 2016 WINEMAKING WINE EAST DiFrancesco uses a Willmes bladder press set at two bars, or 30-35 pounds of pressure per square inch. He checks the juice about every 15 minutes to monitor the Brix level, recording the amount and the time it is measured. "Usu- ally the Brix goes up and then levels off. When it begins to drop is when I stop pressing," he said. DiFrancesco's records showed juice drips reaching as high as 42°-45° Brix, but the final pre-fermentation total, done in three press loads, averaged 34.8° Brix following racking. Sulfur dioxide is added at 75ppm, along with Scott Labs KS enzyme at 100 grams per 1,000 gallons. The juice is then settled for a day and racked—and, if needed, settled for one more day. DiFrancesco inoculated with Lalvin K1-V1116 yeast, chosen for its ability to handle fructose and not get stuck with ex- tremely high levels of sugar. Fermentation took place in a 250-gallon tank, lasting for about three weeks at about 65° F. He noted that fer- mentation of "real" ice wine, with its higher concentration of sugar, could take far longer, sometimes even into late summer. "When we reach the alcohol level we want, we can rack and sulfur it," he said. This par- ticular wine was finished at 11.3% alcohol. He then racks and adds 100ppm sulfur di- oxide and also checks for heat stability, adding bentonite if necessary. The wine is then kept cold for a few months, as low as 28° F, if possible. His small tanks are not refrigerated, so he moves them outside in the winter. Even with the length of cold storage, he said, "We've never had them throw potassium bitartrate crystals." Bottling takes place no earlier than spring, and the 2014 Iced Vidal Blanc wine wasn't bottled until June 18, 2015. DiFrancesco's fil- tering process is very precise, and he noted that some might consider it extreme. The wine was first pad-filtered with Carlson XE675H pads, beginning with 4 microns and finishing with 0.45 microns. The day of bottling it was again pad filtered at 0.45 microns and then final filtered with a Sartorius 0.45-micron membrane cartridge. The primary purpose of this filtering regime is to get the wine as clean as possible, and to eliminate clogged filter delays on the bottling line that could tie up a number of persons, rather than one person doing the filtering be- forehand. Sulfur levels and microbiological stability are closely monitored, and DiFran- cesco looks to have 50ppm free sulfur dioxide at bottling. The finished wine bottle ages a minimum of a month, or longer, depending upon the inventory of a previous vintage. Glenora produced its first two vinifera ice wines in 2014: Riesling and Cabernet Franc. The grapes for both were purchased from and pressed at Sheldrake Point Winery. The pur- chase cost was considerable. DiFrancesco esti- mated about 80 gallons of Riesling (at $50 per gallon) were pressed per ton ($4,000 per ton), while the Cabernet Franc juice was $3,000 per ton. Both the Riesling and Cabernet Franc were inoculated with Lalvin K1-V1116 and fer- mented for about 2.5 months. DiFrancesco believes there is no real differ- ence in processing frozen grapes, regardless of how they were frozen, and his pressing, clarify- ing, fermenting and filtering were the same for the Riesling, Cabernet Franc and the iced Vidal Blanc. However, he believes there is a consider- able difference in the end products. He said, "To me, iced wines are technically more per- fect. The grapes were sound when they were picked, in comparison to the traditional ice wines that have been out two or three months or more, sometimes going through numerous freeze and thaw cycles." - B E C O PA D - Y E A S T & E N Z Y M E S - C R U S H PA D E Q U I P M E N T - S T E R I L E F I LT R AT I O N - W I N E R Y H O S E - O A K A LT E R N AT I V E S STATISTICS AT BOTTLING Wine Free Sulfur Dioxide RS TA Alcohol Total Cases Price Fulkerson 2008 Cab. Franc Ice Wine 125 ppm to new wine; 60 ppm remained at bottling 16.2% 11.5 g/L 12.8% 252 $45 Fulkerson 2012 Riesling Iced Wine 60 ppm 19.7% 11.2 g/L 11.0% Not available $30 Fulkerson 2012 Vidal Iced Wine 60 ppm 20.6% 9.4 g/L 10.0% Not available $26 Glenora 2014 Iced Vidal 100 ppm after fermentation 18.5% 14.3 g/L 11.3% 71 Not yet released (2013 is $20) Glenora 2014 Cab. Franc Ice Wine 50 ppm 21.1% 9.5 g/L 11.2% 126 $40 Glenora 2014 Riesling Ice Wine 50 ppm 22.0% 9.2 g/L 10.1% 141 $25 Sheldrake Point 2013 Cab. Franc Ice Wine 300 ppm to the finished wine 27.4% 7.6 g/L 8.7% 188 $30 Sheldrake Point 2014 Riesling Ice Wine 60 ppm 26.2% 9.6 g/L 8.8% 189 $60 S heldrake Point 2014 Riesling Ice Wine (wild yeast fermentation) 290 ppm to the finished wine 27.7% 9.8 g/L 7.8% 215 $100