The current heat wave in the second week of July may be uncomfortable for us, but it's exactly what we hope to see in our Ventura County vineyards this time of year.
This week we began our first round of grape sampling—not because the fruit is ready to harvest yet, but to see how the vintage is progressing. Every variety is now in veraison, the stage when grapes soften and change color as they begin ripening.
Our initial samples measured between 13 and 19° Brix, which is a measurement of the grape's natural sugar content. Sugar is one of the key indicators we use when deciding when to harvest.
White wines and grapes destined for rosé are typically picked between 20 and 22° Brix, resulting in finished wines around 12–13% alcohol. (A quick rule of thumb is to multiply Brix by 0.6 to estimate the finished alcohol.) Red varieties are usually harvested between 22 and 26° Brix, depending on the style of wine we're trying to create.
Since grapes generally gain about one degree Brix each week, we're estimating that our Ventura County harvest will begin in about three to four weeks.
Harvest has already started in the Cucamonga Valley with Palomino getting picked for low alcohol white wine and in the Santa Maria with Pinot Meunier for sparkling wine. For usm Lopez Vineyard Zinfandel will likely be the first fruit we bring into the winery this season. It is currently sampling at 20 brix.
The recent warm weather has been a welcome addition to this early season.
Temperatures in the 90s naturally slow the development of powdery mildew, one of the biggest fungal challenges in the vineyard. Combined with the grapevine's increasing natural resistance once veraison begins, we're down to just one final mildew treatment before harvest.
The heat also influences the chemistry of the grapes. Warm afternoons encourage the berries to metabolize malic acid, the bright, green-apple acidity that is abundant earlier in the growing season. In our cool-climate vineyards, a few warm days help soften that acidity and bring the fruit into better balance. The result is wines that are rounder, more approachable, and often enjoyable at a younger age. In many vintages, we're actually waiting for acidity to come down before making the call to harvest, so a short stretch of warm weather is usually good news.
