Harvest has begun here at Gainey. It’s when we turn from farmers into chemists. For most of the year, we are farmers, ensuring the grapes have the best chance at growing successfully and creating premium fruit. Ample amounts of sunshine, water, soil amendment, pruning, and some good luck all play into it. But once the grapes are ready to be picked, we turn into scientists trying to manage the fermentation process, keep the pH levels correct, test for acidity, and more.
We started picking our grapes this year on September 12th. We hand-pick the grapes at night because they are less susceptible to microbial spoilage which means there is no unwanted yeast and bacteria. When the grapes are harvested at night they stay cool and firm versus daytime picking where the fruit can be warm. Cool fruit moves more efficiently through the wine processing equipment and delivers higher quality “must” (must= processed grapes).
Red grapes are hand-sorted across a belt conveyor and then passed through a destemming machine. The destemmed grape berries fall into fermentation tanks by gravity flow and are cold soaked for a few days to extract soft tannins and color compounds. The grape stems are removed from the winery and composted.
White grapes skip the destemming process and go straight to a press. Whole clusters are loaded into our press. This process produces cleaner less bitter juice resulting in a softer fuller wine. White grapes are fermented with the juice only.
Yeast is then added into the tanks to start the fermentation process.
In red grape processing, carbon dioxide bubbles pushes the grape skins up to the top. Carbon dioxide is a byproduct of fermentation and the bubbles form at the top of the fermentation tank called the "cap." We have two methods for how to push the cap down: punch down and pump over. We punch down the cap for Pinot Noir, so it blends into the tank and keeps the exposure to air and liquid consistent. For Bordeaux varietals, we use a processes called pump over. With pump over, we pump the juice from the bottom of the tank over the top of the cap. It essentially sprinkles the wine over the top and lets it filter down through the skins. For bigger bolder wines this is a gentle method of extracting the tannins and color compounds.
The juice will stay in the fermentation tanks on average for two weeks for (red grapes). White grapes vary depending on choice of barrel fermentation or tank fermentation. Tank fermentations can be controlled by refrigeration and therefore can be longer and slower to enhance aromas. While barrel fermentations are warmer and faster but benefit from additional texture from the oak barrel.
We test the wines all throughout wine making as part of the maturing process. After the wines are fermented, we check things like: malic acid, TA (total acidity), pH, residual sugar that’s left after fermentation, alcohol levels, and more. Our lab technicians diligently check on the chemistry of each of our wines at our in-house in our production facility throughout the aging process.
It’s often forgotten that farming is one of the most integral parts of the wine making process. There is an art form to high quality farming as well as high quality wine making. A winemaker can put his artistic touch on a style of wine but also relies on the chemistry needed to reach his stylistic goals. It’s a true balance of art and science.