Deb and Dave Burgdorf have been making wine for more than 25 years.

And they know a good grape when they see it.

"Sugars is an important part of the thing, but also the quality of the grape," says Dave, co-owner of Burgdorf's Winery in Haslett. "How has it been handled, is it bruised, are the clusters full?"

And the Burgdorfs say this season's haul has been especially sweet. Mid-Michigan has seen virtually no rain in the past three weeks. Bad for crops, right? But the dry conditions have been a windfall for grapes.

"Those are the beautiful weather conditions to speed up the ripening process of the grapes," says Paolo Sabbatini, a horticulture professor at Michigan State University.

He adds that less rain means a higher concentration of sugar in the grapes, and helps stave off infection.

"Extra water at the end of the ripening process will drive a very difficult problem, which is rot or infection of the cluster," he says.

But there's been no extra water this season, good news for wine lovers. It's also an economic boon for grape-growers, like Sabbatini, and wine-makers, like the Burgdorfs.

"Potentially, we'll have some really good grapes that turn into good wine," Deb says.

And good wine should mean higher demand down the line for Michigan wines -- a shot in the arm for an industry larger than most Michiganders might expect.

"There are 50 to 60 wineries operating presently in the state, and they're producing their own grapes, producing high-quality wines," Deb says.

And if grapes like these keep coming in, wine might no longer be one of the state's best-kept secrets.