October is an anxious month for winery owners in northern California. The vines are full of ripe Cabernet Sauvignon grapes that are just waiting for the right time to be picked. For many wineries in Napa and Sonoma valleys, the Cabernet Sauvignon wines represent the largest majority of their inventories and profit margins.
There are a vast number of variables that have to be taken into consideration when deciding when it is time to pick the grapes. Although color, size and firmness of the berries are all telltale signs that the grapes are ready to be harvested, the most important factors in determining when to begin the harvest are the degrees of Brix (pronounced as bricks), acidity and tannin levels contained in the grapes.
Winemakers will check the Brix level of grapes on a daily basis — often several times a day — in determining the exact moment to begin harvesting their crop. The degree of Brix represents the amount of sugar content that is contained in the juice from crushed grapes.
Most winemakers have a very specific Brix level that they want the grapes to obtain prior to harvest. Since sugar is converted into alcohol during fermentation, this level is representative of what the alcohol content will be in the wine when it is bottled. Basically, 55 percent of the sugar converts into alcohol — so that means a Brix reading of 26 degrees is the equivalent of a wine having 14.3 percent alcohol.
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In determining the exact time to harvest, the percent of alcohol that a wine should contain is important because if the alcohol level is too low, the finished product will taste light and watery. On the other hand, if it is too high, then the wine will taste hot and have a burning sensation.
But, while waiting for that perfect moment, there are a number of things that can go wrong and affect the quality and flavors of the grapes. Vineyard managers will closely monitor the weather forecast because extreme changes in temperature either up or down can ruin an entire crop. Heavy rain or hail can damage the grapes as well.
The 2006 Simi Cabernet Sauvignon from the Alexander Valley region of Sonoma County contains flavors of ripe blackberries and black current. This wine appears dark ruby red in color and retails for $18 a bottle. Although the 2006 growing season had late spring rains as well as high temperatures in both the spring and summer, the total grape production for Sonoma was extremely high. The high temperatures in the late summer caused the grapes to ripen quicker and the wineries began harvest earlier than usual. Many of the Sonoma Cabernet Sauvignons from 2006 are high-quality wines with flavors of ripe fruits.