Producing Finger Lakes Ice Wines: Two Methods to the Sweet Flavors
Jan 9, 2014 – ‘Tis the season for ice wine, which is what our wine crew has been focusing on the past few weeks. Here at Swedish Hill Winery we pressed two different grape varieties of the 2013 vintage for ice wines: Vidal Blanc and Cabernet Franc.
On December 12th we picked five tons of Vidal Blanc grapes that we left on the vines to produce a new ice wines for our sister winery, Penguin Bay. The conditions couldn’t have been better for picking, with temperatures between 13 and 15 degrees Fahrenheit that morning, along with a breathtaking winter sunrise over Cayuga Lake.
Since the ice wine grapes are left on the vines for an additional couple months compared to our other varietals, it is imperative to keep them netted to protect them from the birds and also to catch any clusters that may fall off the vines. The additional time that they are left on the vine allows for dehydration of the grapes which results in higher sugar levels in the juice, around 41.5%. After fermentation this will decrease to about 20-24%.
This year we picked all of the iced Vidal Blanc grapes with our harvester. Since the nets were still on the grapes, our crew was on site to pull the netting apart so the grapes fell directly into the harvester. Using the harvester this year allowed us to extract a larger amount of grapes than if we had hand-picked them, which should result in a larger production than in years past.
After picking, the grapes are loaded directly into the press where the remaining frozen juice is pressed over eight hours. Since grapes have lost about half of their weight through dehydration one ton may only yield around 50-60 gallons, about one-fourth as much compared to the grapes we pressed in September.
Cabernet Franc Ice Wine
While the method of leaving the grapes on the vine until after the first frost produces delicious flavors for the Vidal Blanc varietal, it is not the ideal method for all ice wines. The favored Cabernet Franc Ice Wine that we produce for our sister winery, Goose Watch, is a result of pressing grapes that were picked during their peak ripeness in the fall and then frozen until the temperatures outside are ideal for pressing.
On October 28, 2013 our vineyard crew handpicked 4.7 tons of Cabernet Franc grapes that were left on the vine and picked just after the first freeze, that were then sent into a freezer to keep their condition. On January 8th those grapes were brought out of the freezer and placed on the pressing deck to await an ideal temperature of 14°F for pressing. The next morning we were able to press them as the temperature outside actually increased from the below negative digits from the previous day.
The reason for freezing the Cabernet Franc grapes versus leaving them on the vine is because this variety does not hang as well as Vidal Blanc grapes do. The fruit is thinner skinned and are not as well attached to the stems. The result would be that the fruit is more likely to fall off long before it would be cold enough to freeze on the vine. Also, Cabernet Franc is more likely to develop bunch rots that would produce undesirable flavors. We get a much fruitier and clean juice by freezing off the vine. The juice yield is the same but the color from this technique is superior to freezing on the vine, and overall it makes for a delicious ice wine with natural sweet flavors.
-Derek Wilber, Winemaker at Swedish Hill, Goose Watch & Penguin Bay Wineries