Finger Lakes sweet treat: What makes ice wine unique and difficult to produce

Ice wine — it’s a delectable treat only made in certain climes. Ice wine can only be made with grapes frozen on the vine, requiring vineyards to pick grapes in frigid overnight conditions.

It’s a loss-heavy endeavor and an expensive end product, but some wineries in the Finger Lakes of New York still uphold the tradition, which originated in Germany.

While Sheldrake Point Winery in Ovid didn’t make any ice wine under its label this winter, winemaker Dave Breeden is no stranger to the process. Why do wineries continue to make ice wine, when it’s a costly and finicky process?

“Partly, especially now, it’s because we can,” Breeden said. “There are few places left in the world where you can still make ice wine.”

How do they make ice wine?

As the name implies, a major component to ice wine is cold temperatures. The sweet spot is between 12 and 18 degrees, Breeden said. Too cold and the grapes become too hard to press, too warm and you won’t get the concentration of sugar that is a hallmark of the wine.

The grapes need to remain on the vine, rather than being frozen after being harvested, adding another layer of complication to the process. The grapes need to be picked in the middle of the night when the grapes are not being thawed by the sun. Workers have to wear headlights and work in the cold to cut grapes off the vine.

The grapes are often harvested in January, but it in can occasionally be December or as late as February and March — and sometimes not at all, Breeden said.

The still-frozen grapes are put immediately into the press and pressed while still frozen, Breeden said. The water in the grapes remains frozen and doesn’t press out, so what’s squeezed out is pure grape essence.

The frozen grapes undergo what’s normally a 50-hour press cycle. While a press is typically rotated for a more efficient pressing, that's not the case with ice wine, Breeden said.

“If you put three tons of grapes in the press and start pressing it, it becomes a three-ton block of ice,” he said. ”And if you do rotate the press, it will break the press.”

Instead, the press is set to the highest setting and left to run for the duration. While 50 hours is typical, Breeden recalled a time a client provided hard-frozen grapes that took 170 hours to press.

Why ice wine is sweeter

With the concentrated, sugar-rich juice coming out first, ice wine is sweeter than standard wines. Most ice wines have 35 to 40 brix, a measurement for the sugar content in wine, while a table wine will have 21 to 25 brix, said Paul Brock, associate professor of viticulture and wine technology at Finger Lakes Community College.

The type of grape also matters, as some varieties like sauvignon blanc fall off the vine when ripe, Brock said. The grapes have to be hardy enough to last until the temperature is cold enough to harvest.

“Something like riesling or vidal that keep attached to the vine is going to be a good candidate,” Brock said.

Riesling and vidal blanc, a hybrid grape, are the two most common varieties for ice wine, which is also produced in Canada and Germany. Breeden was aware of other varieties used for ice wine including cabernet franc, cabernet sauvignon and gewurztraminer, which was used by a rabbi to create kosher ice wine at Sheldrake Point in 2022.

Ice wine in the industry

The Finger Lakes may be one of the places capable of producing ice wine, only a handful of wineries produce the delicacy and fewer produce it in any given year. Sheldrake Point Winery is expected to produce the wine from its 2024 harvest if sales of its 2020 ice wine continue as they have, Breeden said.

It’s better the winery didn’t attempt to use its latest crop as the 2023 harvest wouldn’t have held due to warm and wet conditions.

“Grapes are essentially little teeny paper bags of sugar, right?” Breeden said. “If you leave little paper bags of sugar out in a warm, wet environment, bad things happen.”

Loss is part of making ice wine, inherent not only to the process of making it, but in the leadup to harvesting. One Seneca Lake winery lost about 60% of its remaining crop to deer while staff was away for Christmas vacation, Breeden said.

“If you leave the grapes out, you’re basically offering up a big hors d'oeuvre platter for deer, because once it hits November, there’s nothing else for the deer to eat,” he said.

Grapes are also subject to disease pressure from a number of different complications, including several rots — bunch, black, bitter, botrytis — and mildews. The later into a season a grape remains on the vine, the more likely it falls victim to one of these numerous complications.

There is loss even for the grapes which are successfully harvested due to the concentrated nature of ice wine.

“The rule of thumb is that for every three tons of grapes you leave, you get one ton back,” Breeden said. “So you’ve lost two tons already. And then out of that one ton of grapes, you would normally get 170 gallons, and instead you get more like 80.”

Brock said ice wine isn’t a particularly important product to the Finger Lakes wine industry, though he said there’s a bigger market in Ontario, Canada.

“I don’t know anyone in the Finger Lakes relying on ice wine for their profit margins,” he said. “Most of the wineries here are based on table wines.”

Warm winters and eiswein: What does that mean?

Despite being the likely origin of the dessert treat, ice wine harvests in Germany were largely a well-documented bust in 2020. International headlines decried the impact of climate change on the specialty wine, as the winter of 2019-20 failed to produce the frigid temperatures required to freeze the grapes. It was, and remains, the warmest winter on record for Europe.

One vineyard, Weingut Zimmerle, was able to produce the country’s only 100 liters of ice wine in 2020.

This year, however, there has been an ice wine harvest in Germany, highlighted by a cold spell in the first week of January. One winery was able to produce 400 liters of eiswein during the cold snap alone, according to the German Wine Institute.

The first date for harvesting grapes for ice wine in the Finger Lakes was Jan. 17 and the overall above-normal temperatures have limited the windows for picking frozen grapes since. Brock said that’s always been the case.

“I don’t see a risk of losing the ability to do ice wine anytime soon because we’re going to have cold swings pretty much every year,” he said. “I think the better question is will the late season disease pressure be too much to allow it.”

As climate change brings warmer, more humid conditions, the possibility of diseases like rots and mildews only increases.

“The varieties we grow here are relatively resilient with the right management; we can get them to where we need to be,” Brock said. “It’s just that it makes it a little harder, when making ice wine, to get to that point.”

Pairings for ice wine

A wine as sweet as ice wine doesn’t pair with dishes the same way as its table wine counterparts.

“That’s the main one: really strong cheeses,” said Perry Hicks, Sheldrake Point associate winemaker. “And ice wine is an amazing dessert just by itself.”

The wine is really hard to pair with food and get the balance point of sweetness just right, said Breeden.

— Steve Howe covers weather, climate and lake issues for the Democrat and Chronicle and he's looking forward to visiting wineries in the Finger Lakes this summer. Share with him at showe@gannett.com.

This article originally appeared on Rochester Democrat and Chronicle: Finger Lakes wineries make ice wine despite loss, difficult conditions