The first thing I'm studying today is grape varieties. So what exactly is a grape variety? Well, first of all you should know that all of the wines we drink come from one particular species of grape, vitis vinifera. There are plenty of other species of grapes out there. Vitis labrusca, for example, is the common table grape you get at the grocery store, and is a species native to North America. Some people have made wine out of labrusca, but none of it is very good. Labrusca is, however, very useful for its resistance to phylloxera, a bug that destroys grape vines. I'll have more on phylloxera for you later. For now all you need to know is that all the major grape varities you've heard of, like Chardonnay, or Cabernet Sauvignon, are made from vitis vinifera.