Size matters at Big Cork Vineyards in Rohrersville, Md. (Dave McIntyre)

“There’s dew already on the cars,” my wife said, and I thought of the grapes.

It was not yet midnight, and we were driving home to the suburbs from a party in a trendy part of the city we had never visited before. This time of year, no matter where I am, any mention of the weather sends my mind to the vineyards.

Tropical storm forming in the Atlantic? I join grape growers up and down the coast in forming a prayer wall to keep it out at sea. Thunderstorms marching down from the Blue Ridge? I’m constantly checking my weather app to see who’s getting hit. Whenever anyone complains about the lack of rain this summer, I just whistle my lucky tune.

Out West, vintners have more existential worries, as wine country is ringed by a noose of fire. The newscasts, YouTube videos and Facebook posts are terrifying. The annual harvest — a year’s work and income wrapped up in a few short weeks, the wines we will taste, rate, criticize and enjoy for years to come — seems insignificant beside images of charred homes in Lake County and evacuation centers in Calistoga. Though we can’t help wondering whether the wines will taste of smoke.

Here in the East, the vintners are worried about dew, if they’re worried about anything at all. The 2015 vintage in the Mid-Atlantic began wet, with a rainy spring. But the weather turned favorable in July and August, with weeks of warm, sunny days and cool nights and, best of all, no rain.

When I asked Luke Kilyk, co-owner and winemaker at Granite Heights Winery outside Warrenton, Va., whether those cool nights were helping preserve the acidity as the grapes ripen, he squinted and nodded. “There’s a lot of dew, though,” he said. Virginia’s classic humidity, in whatever form, is always on a vintner’s mind. Too much moisture, and mold and mildew can flourish.

Vintners are notoriously pessimistic about a vintage until the last grapes are off the vine and in the winery. On a warm, sunny mid-September Friday, I visited Big Cork Vineyards in Rohrersville, Md., to meet with winemaker Dave Collins and taste his delicious 2013 reds, which will be released this fall. The powerfully concentrated petit verdot recently won Best of Show honors in the Maryland Governor’s Cup wine competition. I was even more impressed with Collins’s savory, complex cabernet franc and lively barbera. As we sipped and chatted on the veranda of Big Cork’s beautiful new winery and tasting room (a must-visit for wine-loving leaf peepers this fall), I asked Collins how 2015 was shaping up.

“Well,” he said with a grimace, “we had an awful lot of Japanese beetles this year.” The beetles are a common pest in Mid-Atlantic vineyards during early summer. They don’t attack the grapes, but they can demolish the vine’s leaves, making photosynthesis and subsequent ripening difficult. The beetles are a double threat: The most effective insecticide against them also kills beneficial insects that prey on mites. “Spray the beetles, you get mites,” Collins said with a rueful shrug.

He led me to a nearby block of petit verdot, where the leaves on the first several vines had been shredded by beetles. The grape clusters hanging from those vines looked healthy, but smaller and less numerous than on vines farther down the rows, where the damage was not as severe.

Collins plucked a grape from a cluster and squeezed its pulp into his mouth. He then rubbed the grape’s skin on the tips of his fingers. “This doesn’t have quite the color I want yet,” he said. “It’s a few weeks off. Good, though!” A few rows farther down, I did the same with a merlot grape. The skin stained my fingertips a light purple, signaling that the merlot was closer to being ready for harvest.

By late September, with the weather holding, vintners began to sound more optimistic. As I write this, harvest in area vineyards is not over, with late-ripening red varieties such as cabernet sauvignon remaining on the vines. But early harvest reports are positive.

“Vintage 2015 will be record-breaking in terms of quality and volume,” predicted Rachel Martin, executive vice president of Boxwood Winery near Middleburg.

“Amazing here as well,” said Michael Shaps of Virginia Wineworks near Charlottesville, who just completed a fruitful harvest at his vineyards in Burgundy, France. Yields were plentiful and quality high, Shaps said, with exceptional ripeness in his petit verdot and tannat.

“So far, so good,” said Kirk Wiles of Paradise Springs Winery in Clifton, Va. Wiles compared this year’s harvest to the exceptional 2009 vintage.

If the weather holds for just another week or two, we could be in for some great local wine from the 2015 vintage. Once all the grapes are in, it can rain for all it’s worth.

McIntyre blogs at dmwineline.com. On Twitter: @dmwine.

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