The crush is on! This crush has been a late one. As of late September, we received most of our white, but have hardly gotten any of the reds. The incredible heat Livermore Valley experienced in July was so high, the grapes actually shut down such that the grape maturation process was delayed durng the heat wave.
The photo above shows grape crushing. Grape crushing is the process of liberating the grape juice from the fruit and removing the stems.
After the grapes are crushed, the grapes are pressed to separate the juice from the skins. For red wines, the juice ferments on the skins. This fermentations extracts tannins from the skin to give the red wine its color and flavor. On the other hand, white wines are generally pressed immediately after crushing, because white wines are more delicate and the tanins would detract from the general fruity character of a white wine.
Fermentation is the process of converting the suger in the grape juice into alcohol. Typically, the picked grapes have about 22-25% sugar. Yeast, either naturally occuring in the grapes or added by the winemaker, consumes the sugar and produces alchol and CO2. It takes roughly about a week for the fermentatin process.
Some of the enjoyment of visiting a winery during the crush is the wonderful smells emanating from red wine fermenting.