Harvest is upon us! This week we'll be picking grapes for our Santa Cruz Mountain Pinot Noir, Mourvèdre, and Carignan. I'm often asked how do we know when to pick? Many factors contribute to grape ripeness, but the main ones are: sugar, flavor, acid, and pH. The sugar level in grapes is measured in degrees Brix via a device called a refractometer. The preferred sugar level depends on the winemaker and style of wine. Flavor is important and can be deceiving. Sometimes grapes taste very sweet from an early heat spike, but the flavors are still green, requiring more time on the vine.
Acid is important to a wine's structure and ageability. Three main grape acids are malic, tartaric, and citric. If the total acidity of these is too low, then the wines may lack structure and taste weak ("flabby," as we say). Too much acid and the wines may be too sharp. The pH of a wine is crucial because it impacts flavor, color, aroma, stability, and fermentation rate. So knowing when to harvest is based on the alignment of these factors to achieve the best possible wine.
George Troquato, Winemaker