It was dark… and way too early. Not even 5:30am. I was a little worn from the night’s Merlot. But I was ecstatic: I would help Bernardus harvest Pinot Noir from its seven-acre Ingrid’s vineyard.

Last harvest, I traveled all the way to Bordeaux, France, to join the effort – braving bums fighting me for my sidewalk sleeping spots, bus drivers shouting at me for unknown reasons, and hostel vagabonds who smelled so bad I didn’t mind them stealing my soap – only to be shooed away on a heartbreaking technicality called a “work visa.” But now I would have my chance.

When I got to Bernardus at 7am on a late September day, I was greeted by jovial vineyard manager Matt Shea and a team of 20 pickers. But something else was present, too: winds from the south, abnormally tropical air and then, something spookier: a sprinkle from the sky. That moisture carried a reminder: Mother Nature is always the co-winemaker.

Rainfall during harvest time is never good for Pinot grapes. Their skins are thin and they’re prone to botrytis, a devastating mold that causes grapes to split open. One way to lessen this risk is to remove excess foliage throughout the season, enhancing ventilation and getting the grapes some sunshine (plus the vine’s energy goes to the fruit, not the leaves). Smaller wineries with low-yield vineyards can maintain such methods, whereas it’s trickier for bulk grape producers.

But Pacha Mama has other tricks: Strong winds can blow grapes off the vines, heat waves can ripen grapes prematurely or frost can choke the ripening process and reduce crop size significantly.

This year’s growing season included one major, and peculiar, event – the storm on Oct. 13, the biggest early autumn weather event since the ’60s.

Depending on who you ask and what varietals are discussed, it’s going to impact the ’09 bottles in different ways.

The rain forced many winemakers to pick their grapes before they’d fully matured, meaning they’ll have to deploy more post-harvest strategies to balance flavor. Others had to discard grapes that had been affected with rot, slashing yield. Hahn winemaker Paul Clifton noticed that even Syrah and Merlot were affected with botrytis, which is unheard of. “It seemed to hit about seven days after the rains,” he says, egged on by the humid weather that chased the storm.

The growing season’s heat waves, meanwhile, kicked up grape sugar levels in a lot of Pinot Noir vineyards; when that sugar is converted to alcohol during the fermentation process we can expect fuller-bodied wines. This drives winemakers to spend more time pondering ways to implement fancy techniques like reverse osmosis or acidulation to give potent wines better acidity and freshness. An occasional complaint with Santa Lucia Highlands Pinot is that it can be a touch too sweet and strong from the robust fruit. That means this year’s weather could make it even tougher to win over critics with alcohol-sensitive European palates.

Talbott winemaker Dan Karlsen knows a thing or two about Pinot Noir, having been the winemaker at Chalone for over 10 years. While he thinks we’re a little spoiled by good weather, he feels blessed to have survived two power outages with back-up generators.

“In Burgundy, they’re always dealing with the rain,” he says. “Here, we’re complacent. We barely ever see it. I’m happy with the way things turned out. I have a few more gray hairs, but in this business, you can’t cry about it, you have to have a plan B.”

Chardonnay winemakers face their own challenges – those who harvested before the rain will have to work with grapes sweetened by the heat and soured by the early harvest (no easy task) and those who harvested after the storm will need to figure out ways to battle the rot (even tougher), including adding sulfur dioxide, which comes with its own complications. Another problem with harvesting after heavy rain is that grapes can lose their sugar, forcing winemakers to add grape juice concentrate.

Look out for wineries that didn’t get their grapes in before the rain. One way to do this is to read their info on their website. A good winery should list specifics details like the date(s) the grapes were picked, their brix (sugar level), pH (acidity), type of fermentation and filtration methods, alcohol percentage and amount of residual sugar.

Chills had a greater effect on local Cabernet, Syrah and Merlot than the rain, according to winemaker Damien Georis, University of Bordeaux grad. “We had some frost this spring which slowed things down,” he says. “This year we harvested our Merlot in early November – normally we pick in late October,” he says. Luckily for him, those varietals fared well through the wetness because they have thicker skins that make them less susceptible to rot (though he did mention that Syrah grapes can dilate with a lot of rain and that, “If the grapes break, you’re screwed”).

Less common Monterey County varietals seemed to thrive in the abnormal weather. The Portuguese varietal Loureiro is normally used as a blending grape since it’s usually too acidic to be bottled by itself. Not this year – the sugar boost summoned by the heat wave should balance its normally acidic profile. The rot-resistant Louiero grape is native to Portugual, where they see plenty of rain. Tannat, popular in Southwestern France’s Madiran region, thrives in warmer climates and if it’s not warm enough, the grape’s thick skins fail to ripen, making for an astringent beverage that’s tough to drink without fatty foods like duck confit. This year local Tannat ripened three weeks earlier than normal – which is a good sign. Maybe Mother Nature’s becoming a fan.