If used, oak can have a profound effect on wine. Not only can it affect the color and flavor, but it also adds tannin and complexity. Now, wines fermented and/or aged in stainless steel give a more natural, crisp, and clean taste to a wine, but wines vinified with oak can be just as good, if not better. Oak barrels allow a small amount of air in, which not only softens harsh wine tannins, but also evaporates alcohol and water. This leaves behind a concentrated evolving wine, with more flavors and tannins added from the oak. But the kind of oak and how it is charred will determine the additional flavors of the wine. What kind of oaks and char levels are used?
First, let's delve into the different oaks. The oaks used normally come from North America, France, and Slovenia. North American oak has more bold flavors, due to the preparation and higher amount of lactones, giving off more intense, sweet, and vanilla flavors to a wine. The best of North American oak is found on the east coast and midwestern United States. Other sources are Oregon and Canadian oak.
French oak imparts less flavor and aromatics, but offers a higher amount of wood tannin, making it a better aging oak. There are many forests that are used to harvest the oak, each used for different types of wine. Tronçais is used to create long lived reds with big tannins, while Vosges is used to impart oak to faster maturing wines like Pinot Noir and Chardonnay. Other forests include: Nevers, Allier, Centre, Bertrange, Jupilles, and Limousin.
Slovenian oak is normally used by Italian winemakers, and imparts low aromatics and medium tannins to a wine. This allows the juice to truly express itself, while gaining a small tannin boost for richness and aging. Eastern Europe is also being looked at by the French as a cheaper alternative, mostly from the Black Sea and Baltic areas.
Now we can get to the char. The toast level of a barrel will affect wine differently as well, and can give amazing flavor profiles such as yeasty bread, creamy vanilla, smokey bacon, and spicy cinnamon and nutmeg. A low char on a barrel will impart more oak flavor and tannin. A higher char will give off more flavor quickly, remove some of the coconut, but can reduce the color of a wine.
It is up to each winemaker to determine the type of oak and char they would like to use on their wine. This greatly determines the style, and can turn good juice into a great wine, or vice versa. This can also affect the price of a wine. If expensive French oak is used, and the wine is aged for 22 months, with more evaporation and concentration, the wine will cost much more than one fermented and aged in stainless steel. I say try out all types and see which you like the best- you may just like them all!
(photo courtesy of flickr)