Yeah, we got pretty deluged with rain last night. I know people are reporting similar wetness all over Napa and Sonoma County. It certainly adds to the drama of things as harvest draws to a close…

The amount of rain grapes can tolerate really depends on a few factors.

1. The varietal. Thin-skinned, tightly clustered varieties do not do well in rain, i.e. anything from the Pinot family, Chardonnay, Gewurtz, Zinfandel. If moisture gets trapped inside the tight cluster it is a recipe for botrytis. On the other hand, thick skinned and loosely clustered grapes such as Cabernet and Syrah manage to do pretty well in the rain. When I was at Ch. Lynch-Bages in Bordeaux last harvest it rained for six days straight and there was suprisingly little rot. Right now, most of the thin-skinned stuff is in, though there are certainly cooler vineyard sites that may have a rough go of it this year.

2. The weather after the rain. You want warm and breezy to evaporate the moisture, more cold and damp just exacerbates rot.

3. Crop levels. Believe it or not there are some Chardonnay vineyards still not picked yet and all of them look pretty over-cropped to me. The result is that clusters tend to sit on top of each other creating the proverbial “cluster fuck.” The huge crop impedes air flow through the canopy which limits evaporation or blowing off of water. Water thin skins sugar= fungus amungus…..

4. The Human Factor. Wine folk in California tend to get very verclempt at the site of rain– simply because it does not happen very often. They forget that rain is a matter of course throughout the vintage in many of the best wine growing regions in the world– Bordeaux, Burgundy, Champagne, Piedmont, etc. This results in the “freak-out” effect where people start pulling in under-ripe fruit while panicking about rot (witness 1998).
That said, it has been my experience this vintage that winemakers are being TOO cool about hanging fruit too long. Since the current market really punishes “under-ripe” or “green” tasting wines it is safer for winemakers to deal with potential issues with rot than to make “green” wines. That said, the long and relatively even growing season this year has made for phenolic ripeness at lower than normal alcohol levels. For instance, I picked the second block of Cabernet at 24.5 brix and it has no green flavors at all. Since many winemakers are so worried about green flavors they are letting similar fruit simply hang for the sake of hanging which does little to better wine quality (if anything it starts to limit varietal character). Winemakers sometimes forget that you have to play to the foibles of any given year…..

I will now step down from the soap box….

As for me, everything, save for Harwood Vineyard, is in. Harwood is ready to come in and will be crushed on Saturday. Harwood, which is just around the winery, is showing no signs of rot (the benefit of Syrah and Merlot). Probably because it is such a windy, Carneros, site.

Brian Marchus found one cluster with rot while we were picking Abbastanza but other than that it was pretty clean.

Thanks for the great question Drew!