The 2010 grape growing season so far

Image from rrvw.org

While most of the eastern U.S. swelters with heat and humidity California is setting under a dome of cool Pacific air this summer. On the day I write this the high temperature in Santa Rosa ( Sonoma County), CA will be at least 15 degrees below average.

One of the most popular questions from wine country visitors is, "How is the vintage looking this year?"   And the typical answer they'll get is, "Great!"   But when does anyone actually know if it's a "vintage" year?  Realistically, probably about six months after harvest.   However, as the season progresses there are signs.

Note that I'm speaking definitely not as a viticulture expert and I'm speaking for Sonoma County and nearby areas.

Grapes go through steps in their development (dates are approximate):
Bud break - March
Bloom then fruit set - May
Veraison (ripening process begins) - August 1st
Ripe - Oct 1st, plus or minus a few weeks

One key thing grape growers look for is early or late development during the season.   They fear late ripening grapes because the later the harvest the greater chance of rain before the grapes are picked.   Rain and mature grapes don't go together.

Spring was late in 2010 as the weather stayed wetter and cooler than normal.  The summer is cooler so far.  I recently read in the local paper the average highs this summer are about four degrees below normal for Santa Rosa.   Last I saw the growing cycle was running at least two weeks behind normal.

Is this bad?  It depends.   Slow growth is the vineyards can yield excellent fruit.  If heat was all you needed we'd be getting our Cabernet from Fresno!  It's not just ripeness, it's maturity.   There is a sugar and acid balance that takes time.  Though I'm guessing most vineyards folks are praying for a sustained heat wave in August.  Or at least no measurable rain until November.  Or both.