Before I start in on all the wonderful things we did in wine country, I thought I'd give some of the information on wine that we learned on this trip first.
First, red and white wine can all made from purple grapes. While some green grapes are used for some white wines, others are made from red/purple grapes. What determines whether a wine is red or white is if the juice of the grapes had been in contact with the skin of the grapes. The skin gives the pigmentation of the wine and releases tannins into the wine. The different grape varieties give the wine its name; cabernet sauvignon, merlot, malbec, cabernet franc, syrah, etc. (All of the above types of wine we sampled during our tastings)
I think everyone has seen the I Love Lucy episode where she stomps on the grapes. As much fun as that would probably be, its not very economical or practical. The grapes are squeezed to release the juice. The first pressing is the best one, and is usually used for the top line wine that the winery makes. Then the grapes are pressed again, and again. Usually grapes are only pressed three times. If the grapes are squished too much, then the seeds break and the flavor can turn bitter.
After the juice has been extracted from the grape, the juice needs time to ferment, usually a few weeks. During this time, the sugars in the juice turn to alcohol. The wine is usually stored in big tanks that will allow the carbon dioxide that forms to escape.
Then, if it is a lower quality red wine, white wine, or rose, the wine is bottled. Some red wines however, get put into oak barrels to age. The longer the wine is in the oak barrel, the more flavors get drawn out of the wood into the wine. There are two kinds of oak that are used, French oak and American oak. Each oak gives a different flavor to the wine. Each barrel is used just three times before it is discarded. The first use of the barrel is the best one, and is usually used for the top line wines.
Some wine is aged in the oak barrels for two years, others for 3 or 6 months. It depends on what flavors or undertones the winemaker desires in the wine. The different flavors that sophisticated palates can taste in wines come out during the fermentation and storing process. Those flavors (tobacco, blueberry, cherry, citrus, smoke, cinnamon, etc) are not added to the wine, but simply come out of the juice and sommeliers (wine tasting experts) use these flavors to characterize wines.