Veraison 2010!

And... (drumroll please) we have veraison for 2010.  It's actually less far behind than we were expecting, more like one week than the two weeks we were late at flowering.  [As points of comparison, I wrote about veraison on July 27, 2007, July 30, 2008 and July 24, 2009.  If you're interested in learning more of the science behind what happens at veraison, check out particularly the 2007 post.]

We've had ideal ripening weather for the last week or so, with highs in the upper 80s and low 90s, cool nights, and sun.  As usual, the Syrah is furthest along.  We saw our first red berry last Friday (July 30th) and clusters are coloring up rapidly at this point:

It's important to remember that even as some clusters are coloring up, there are others on the same vine that are still all green.  From an extended ramble through the vineyard this morning, I'd estimate that we're probably 30% through veraison in the Syrah:

Oddly, the other variety in which we're seeing significant veraison is Mourvedre, which is typically our last varietal harvested.  The typical spread in veraison times (about 3 weeks) is not as great as the typical spread in harvest times (about 2 months) so it's not an indicator that we'll harvest everything at the same time.  Still, it's a surprise to see it go before Grenache.  Note the couple of exposed stems, a sign that either (more likely) birds or (less likely but possible) winemakers have keyed in on and tasted the ripest berries:

Finally, one other photo of Mourvedre shows how uneven the veraison process is even within a single cluster.  I'd estimate about 20% veraison in Mourvedre overall, but clusters can have berries that are purple and sweet, purple and sour, and green all at the same time:

As for the other red varieties, well, Ryan reports that there is the first sign of veraison in Grenache, but I couldn't find it in my walk this morning.  And Counoise, which is always late going through veraison, doesn't appear to have started yet.

The fact that we've actually caught up somewhat in what is the second-coolest summer since 1997 is a great indicator of the weaknesses of using a measurement like growing degree days to measure ripening conditions.  The hottest days are not good for photosynthesis; above about 95 degrees, most grapevines stop photosynthesizing as they close the pores in their leaves to conserve moisture.  So while you can get dehydration in periods of extreme heat, you don't get physiological ripening.

Still, I'm glad we're in Paso Robles and not in the North Coast.  The reports I'm hearing from Napa and Sonoma are of days spent socked in by fog, temperatures topping out in the 60s and 70s and ripening three to four weeks behind normal.  I'm all for cool weather maintaining good acids, but grapevines do need sun.  I just hope that if things stand as they are now, reviewers will take the time to evaluate the different regions of California on their own merits and not be tempted to paint with an over-broad brush.