Clove

Clove. It's sometimes used as a descriptor in wines, primarily red. And, more than anywhere else, you'd be most likely, at least in my experience, to find it in higher end Rioja wines and of course those of Burgundy.

So, where does it come from? Red wines from Burgundy are going to be Pinot Noir. Red wines from Rioja are predominantly Tempranillo. Best I can tell, those grapes are not related.

And, clove comes from the clove tree. It's an evergreen and it is indigenous to southeast Asia, not exactly a major wine-producing area and certainly not close enough to Burgundy or Rioja to for the wines from those regions to absorb the clove through the air. Even if they could, there are other wine regions far closer and they would get the clove first, but they don't.

So, it must be the chemistry. I was interested in understanding this, so over time, I learned a little bit about what is going on here. 

Clove, as well as cinnamon, nutmeg, bay leaf, and basil, has a lot of a guaiacol called eugenol in its oil. That's right, if you extract the essential oil from the clove flower bud, there is that distinctive aroma and that aroma gets stronger with the presence of more and more eugenol.

Who cares?

We do. And, the reason that we do is because oak, particularly sessile oak, or quercus sessiflora (I had to google that one) is loaded up with eugenol. 

Digressing for a moment, vintners of higher end wines custom order their oak barrels. They don't simply take what they can get, but they are very specific. And, to create the classc characters of red Burgundy and red Rioja wines, a fair number of them request sessile oak. And they require that the oak be naturally seasoned before the staves are made into barrels. And, natural outdoor seasoning allows the aromatics, including eugenol, to come through fully during the seasoning process whereas oven seasoning does not (the acceleration of of oevn seasoning does not give the chemical proceses time to occur).

After seasoning, the oak is typically toasted. This involves heating the staves so that they can be shaped into a barrel. To a point, the more the toast on a barrel, the more that the eugenol comes to the fore.

But, barrels with this sort of seasoning and toasting tend to perform best with medium-bodied wines. They might not have the natural tannins necessary to work with the often much higher alcohol content of, for example, Cabernet Sauvignon, particularly from warmer weather like Napa Valley. 

And, therefore, primarily, at least as well as I can understand it, that is where the clove (and cinnamon and nutmeg) that we get in certain red wines comes from and why Burgundy and Rioja tend to have more of it than other wines.