As the winter approaches, winemakers in colder areas of the country such as Michigan, upstate New York and areas of Pennsylvania are adjusting to the weather conditions to prepare to make their unique ice wines.
Ice wines are sweet wines made from frozen grapes that are more expensive due to the meticulous production process.
How Ice Wines Are Made
"Ice wine grapes have to be frozen naturally on the vine," Matt Cassavaugh, winemaker at Casa Larga Vineyards in Fairport, N.Y., said.
This means that grapes intended for ice wines are kept on the vine after harvest for normal wines so they can reach the required temperatures. Weather regulations by the Canadian Vitners Quality Alliance (VQA) allow ice wine harvesting to occur at a maximum temperature of 17.6 F, said Cassavaugh.
"We are looking for three consecutive days where the temperature does not exceed 17 degrees," Scott Bubb, owner and winegrower for the Seven Mountains Wine Cellars, said.
The grapes are harvested when the temperatures are really low, so that the grapes remain frozen when they are being pressed.
"Some people go out at 2 or 3 a.m. because that's the time that the grapes are at their coldest," Bubb said.
With non-frozen grapes it usually takes about an hour to press a batch that will yield anywhere from 150 to 180 gallons of juice. With frozen grapes however, they are pressed for a day and a half and only yield 30-50 gallons of juice, according to Bubb.
"When grapes are pressed in ideal ice wine conditions, much of the water in the juice is frozen and therefore left behind as ice, yielding much less juice but juice that is more concentrated, sweeter and aromatically complex," Cassavaugh said.
That is why ice wines are so much sweeter than regular wines and are often used as dessert wines.
How Winter Will Impact Harvest/Production
Weather plays a huge role in how successful a year's production of ice wine will be and if the grapes will be useable.
"We want it to get cold early enough that they freeze before they rot to the point where they cannot be used," Bubb said.
The cold waves that were occurring through the month of November were beneficial to wineries in upstate New York because they allowed the grapes to freeze early before they rotted, Cassavaugh said.
"The freezing temperatures came more quickly than in the past few vintages and temperature swings have been minimal," he said.
Wineries in areas like Pennsylvania generally harvest in the latter part of December, so they are hoping that temperatures will drop enough to freeze the grapes on time.
"It still hasn't been cold enough yet to get three consecutive 17-degree days. We are hoping that that comes," Bubb said.