Testing the Grapes

The days are getting shorter, the nights cooler, and the grapes sweeter! It’s time for us to start doing routine checks on the sugar, acid, and flavor factors of the grapes. This is exciting time of year…the grapes change almost daily during these last few weeks of summer, and harvest is just around the corner.

Carol and Dolce checking on the grapes.

Waiting for grapes to drop.

So just how do we measure these values? We start by running around the vineyard, collecting random clusters for each variety. We usually shoot to collect 1-2 gallons grapes per acre for each sample.

Removing clusters for analysis.

Once we’ve collected our sample, we dump it into a bucket and start pressing them by hand. Each variety is analyzed separately as they ripen at different times, are harvested at different dates, and are processed individually. A juice sample is drawn from the crushed grapes. We measure the titratable acidity (or the detectable acid) with a simple acid-base titration. The sugar is measured using a refractometer. For red grapes, we shoot for sugar levels between 23-25 brix (roughly % sugar); for green grapes (white wine grapes), anywhere between 21-24 brix, depending on the variety.

Testing the sugar level of the Merlot sample. This sample was 18.4 brix.

The last factor, flavor, is up to the winemaker! If it tastes good on the vine, it’s probably close or ready to be picked. Because these 3 tools are vital to picking your fruit at the optimal time, we measure them at least 1-2 times per week throughout ripening.

Our first harvest is projected to take place September 25th-26th. We will be processing 7-8 tons of our estate Chardonnay. Look for upcoming posts with details of picking opportunities – come join in on the harvest fun!