Hybrid vs Cross vs Blend
One area which often confuses new wine drinkers is how a wine becomes a blend, a cross or a hybrid. It really is quite simple when you sit down and discuss the three!
Let's start with blends. When you have a finished wine which is a blend, it means two or more different grape sets went into that wine. You can have a multi-year blend. For example, if a winery picks Merlot grapes in 2002, then again in 2003, then again in 2004, they might create a multi-year blend of "merlot wine" which has grape jucie from all three years. Why would a winery do this? Every year's harvest is different. If one year had a lot of sun, the grapes would taste different than in the subsequent year when there was a lot of rain. By blending together wines from a number of years, the winemaker can even out the flavors and reach some sort of ideal flavor.
You can also have a multi-grape-type blend. Bordeaux is a prime example of this. When you buy a wine from Bordeaux, it is typically a blend of Cabernet Sauvignon, Merlot and Cabernet Franc in varying percentages. One year they might use 50% Cabernet Sauvignon and 50% Merlot. Another year they might use 25% Cabernet Sauvignon, 25% Merlot and 50% Cabernet Franc. It is all dependent on the weather conditions for the year, how well the grapes grew and what combination tastes best for that year.
In general the reason a winemaker blends the wines together is to create a better final product. They want the nuttiness from wine X, the body from wine Y to create a finished wine Z that has the ideal aspects of both components.
In horticulture a cross is a child of any two parents - but in winemaking a cross is specifically a child of any two SAME SPECIES plants. You create the cross of pinot noir and cinsault and have as a "child" the plant pinotage. Both of the parents are in the vitis vinifera species, so the child is also vitis vinifera. Really, knowing what the parents of a given vine are are not that important in the grand scheme of things. Does it really matter who the parents of pintoage are? Does it matter who the parents of chardonnay are? Does it change how you feel about chardonnay? Probably not :) Still, it is important to know what a cross is, if only to understand what, therefore a hybrid is.
In winemaking a hybrid is ONLY a cross of two DIFFERENT SPECIES plants. You might ask youself why it really matters - if you are making baby plants, who really cares who the parents are? The issue here comes down to snobbery :) You can equate this in your mind to purebred dog raisers who only want their dogs to have 100% pure blood of a given type.
For some wine drinkers, the only good wines are wines of the vitis vinifera species. These are the traditional European wines such as Chardonnay, Cabernet Sauvignon, Pinot Noir and so on. These wines are thought to have the best flavors in wine (by those snobs). They look down on wines made from other species, such as the vitis labrusca species. Concord would be an example of a vitis labrusca grape. Vitis Labrusca comes from the eastern United States while vitis vinifera comes from Europe.
So if you made a "cross" of vitis vinifera grapes, like mixing Cinsault and Pinot Noir, you get a vitis vinifera child, Pinotage. Purists would say this child is just as tasty as its parents because it is a pure breed.
In comparison if you "crossed the streams" and mixed a vitis vinifera mother with a Vitis Labrusca father, you would get a "hybrid". It is almost as if they consider the hybrid child tainted by the vitis labrusca influence. Some wine drinkers find vitis labrusca grapes to have a somewhat "foxy" flavor to them so they automatically consider any hybrid grapes to be equally undrinkable.
In fact, my understanding is that the EU has banned all hybrid grapes from their countries. They only want people growing purebred Vitis Vinifera grapes on their lands.
I am personally very fond of many vitis labrusca and hybrid grapes. They can be grown very well in places that vitis vinifera grapes cannot grow, and they have a wide range of flavors. I do not find them inherently better or worse than vitis vinifera grapes, any more than I would say a tomato is inherently better than an apple. They are different things, with different flavors, and both can be tasty.
It is important to understand the difference between these three wine terms, so that when you see a bottle of wine and it is labelled as one or the other you know what it means. However, in the end a wine is a wine and should stand on its own merit. It should not matter who the "parents" of a given wine are. It should only matter if you personally enjoy it, and if you do, how you can get your hands on more :)
Wine Terms in More Depth
Wine Basics Main Page