The other day I went on a tour at Pride Mountain winery with some charming clients. Jason gave a tour that went through the great caves, tasting along the way. Now, being the driver I didn't taste the wine, but it was more than worth it for the presentation. One of the things that Jason reminded me about was the preponderance of Cabernet Franc in Bordeaux over Cabernet Sauvignon.
Being in Napa where Cab Sauv is the staple that seems a little odd. After all, Cab Sauv is such an easy going grape, tough, yet refined and able to produce abundantly in even the chanciest conditions. The only thing it doesn't like too much is cold. It is a sun loving plant that benefits from a long growing season, and a cool year like 2010 means that vineyards tucked in the hills and hollows had a challenge getting ripe, and quite a few didn't.
After that we went on a tasting tour with a winery owner and while he was pouring the Cab Franc I mentioned that it was more widely planted in Bordeaux, and he was surprised. I suggested that maybe it ripened earlier than Cab Franc, but he said, "Not by much". Now, he is a grower so I assume he knows what he is talking about so it got me thinking. Why would the French grow more of a grape that produces less quantity?
You need to understand that Cab Sauv is the child of the red Cab Franc and the white Sauvignon Blanc. The pollen was exchanged in the vineyards of France about three hundred years ago producing what is known as a clone. That's a mutating branch that produces a different type grape. The growers trim it off, plant it, and then if it produces good wine they propagate it.
So, not surprisingly the three grape varietals like similar conditions and while white Sauv Blanc comes in early, the other two reds need more time in the vineyards. But, there are many reasons for a preference. Tradition, Cab Franc has been grown in that reason for a long time and they know the grape well. Weather, while there are similarities between Napa and Bordeaux there are some glaring differences too. Wine making traditions and techniques differ in response to that weather. When you take that all together it offers some clues.
I think that the key is the tannins, the rain and the sun. Cab Sauv is high in tannins and Napa tends to have a long growing season with a lot of sun and heat late in the year. Cab Franc has substantially less tannin and Bordeaux often gets rain earlier shortening the growing season.
Tannins are found in the seeds and the skins. When the rain comes it washes the tannins out of the skins, but the rain also promotes mold. The popular blending grape Petite Verdot (little green one) is often blended in under ripe to provide a profusion of tannins. It is one of the reasons that ripe Petite Verdot makes such a dark wine, tannin rich skins.
But the other thing that breaks down tannins is the Sun. Tannins are sulfur compounds, and just like in humans, sulfur in the skin prevents wrinkles and damage. That is why it is known as a beauty mineral. That strength is what makes the Cab Sauv such a nice grape to grow. In Napa growers depend on our long, bright growing season to soften the tannins in the skin of the Cab Sauv. The result is that Napa Cabs are typically ready to drink much sooner than French Cab blends. Also, the French typically blend to make up for the relative strengths and weaknesses of that year's crop. There are many Napa wineries that produce a 100% Cab Sauv.
So, maybe the reason the French grow more Cab Franc is because they don't have as much Sunlight to beat the crap out of the Tannins. Cab Franc doesn't have nearly as much tannin as Cab Sauv. I could be wrong about this, but organic chemistry is pretty predictable and the chemistry of wine grapes is a long studied subject.
|
