If you spotted these grapes, brown and frozen like rocks, in the dark recesses of your refrigerator, you'd probably throw them out.

ERIE, Pa. — If you spotted these grapes, brown and frozen like rocks, in the dark recesses of your refrigerator, you'd probably throw them out.

Bob Mazza knows better.

Since 1984, he's been making ice wine, a specialty dessert wine that is pressed from frozen-on-the-vine grapes that are prized for their concentrated sugar content.

Mother Nature, not the growers, dictates the schedule of the annual harvest. Ice wine can't legally be given that name until the grapes have been frozen on the vine at something less than 17 degrees.

Sometimes that doesn't happen until mid-January or later.

It happened on Monday this year, and Mazza was ready.

By 1 p.m., with temperatures in the low teens and a biting wind blowing off Lake Erie, Mazza had assembled about 20 people, most buried beneath layers of sweatshirts, jackets, hats and hoods, to begin picking frozen clusters of vidal blancs from the vineyard behind his winery on East Lake Road.

"These are beautiful," he said of the grapes, which hung in heavy bunches beneath a mesh netting designed to keep the birds away. "In another month, they might not look so pretty."

The ice wine that Mazza and his staff began pressing Monday afternoon will be bottled in slender blue vessels half the size of a normal bottle of wine and will sell for $42.95 each.

The 2009 version of the wine will be served in early 2011 at the inaugural ball for Gov.-elect Tom Corbett.

Mazza, who has three 1-acre plots of grapes for ice wine, expects the crop will produce wine valued at about $250,000.

It's a big number.

But mostly, Mazza said, it simply offsets the fact that the harvests is only a fraction as big as the one he could have harvested when the grapes were still plump and juicy in October.

Mazza has high hopes for this year's crop.

"We had a great growing season," he said. "If you start out with mediocre grapes, there is not too much you can do about it."

Volunteer pickers, who were rewarded Monday with hot coffee, mimosas and the promise of a bottle of wine when it's finished in a few months, included John Oliver, president of VisitErie, the county's lead tourism promotion agency.

"I came out the first time for a life experience. Now I come to help Bob out," he said.

It was a chance meeting that prompted Amanda Hiwiller, a 31-year-old customer service employee for US Airways, to make the snowy drive to North East.

Hiwiller said she was working at Erie International Airport a few days ago when she checked in Mazza's son, Mario, the winery's enologist or wine expert, who was on his way to Australia.

Hiwiller said she recognized his name and asked about the ice wine. Before he climbed on his plane, Mario Mazza asked if she would like to volunteer.

The combination of 19 mph wind and 14-degree temperatures left Mazza's crew to pick in what felt like subzero temperatures.

Hiwiller said she didn't mind.

"I'm still smiling," she said. "This is exciting."