At Stone Hill Winery ~ quality is always at the forefront of everything we do! And in order to ensure the very highest quality we want to control what goes into OUR wines. That is why we have our OWN vineyards (190 acres~making us the largest grape grower in Missouri), & we are responsible for growing and harvesting 95% of the grapes we use. With quality in mind, the exact time when to harvest each grape variety is extremely important. This is determined primarily by the ripeness of the grape as measured by sugar, acid and tannin levels. Berry clusters are collected and a refractometer is used to measure the sugar (Brix) and titration tests measure acid levels of the grape. Currently, tasting is the only way to measure tannin ripeness, which takes experience and skill to do accurately.
For the utmost quality almost all of our grapes are harvested at night, with the crew starting at about 10 p.m. usually until 5 a.m. Daytime temperatures change the sugar composition of grapes, so picking at night when it is cooler means sugar levels are stable, and this keeps surprises from happening during fermentation. Cool fruit is firmer which means less bruising/crushing while picking and less oxidation. The lower night temps also help with factors of crispness, and concentrating aromas, and the flavors of the fruit. An added benefit is nighttime also helps with fewer interference from snakes and bees, etc. Picking grapes when they’re cool also reduces the energy needed to cool them before they can be pressed or fermented.
Mother Nature is heavily involved in harvest and she is ultimately telling us when it is time…..whether it is trying to get in crop before a week of rain bursts the ripe grape clusters or a dry high heat speeding up the sugar contents. Once the grapes are safely on the truck, the vineyard manager’s job is complete and all the pressure shifts to the winemaker. Like most things, it takes an entire team! And ours is dedicated to quality!
See night harvest in action, click to view video!