There are a few different types of wine barrels out there but both American oak and French Oak are used most frequently for barrel aging wines. They contribute aromas, flavors, and tannins to a wine, but the results are quite different. Winemakers often choose to age their wines in French or American Oak, or a combination of the two in order to get the desired profile envisioned for the finished wine.
Top Pick for French + American Oak:
• Alma Rosa 2014 Pinot Noir
So what is the difference between French oak and American oak?
French oak is much tighter grained and less dense than American oak, thus imparting more subtle flavors and firmer, but silkier tannins. It also can impart roasted subtitles and hints of spice to the finished wine. French oak barrels are also known to provide a certain elegance and creamy quality in the wine, largely due to the silky tannins. Grape varietals such Chardonnay tend to benefit most from aging in French oak.
Since American oak is denser than French oak and it can be sawn instead of hand-split, which makes it considerably cheaper than French oak. American oak is sweeter and contains more vanillin compounds which tends to give more obvious and stronger flavors. American oak is most associated with the actual oaky aromas and flavors along with sweeter vanilla characteristics, which makes it a good choice for bolder grape varietals like Zinfandel.
Now, if only it were as easy as deciding which flavors are ultimately wanted in a wine and picking an American or a French oak barrel! Oh no, winemaking is an art just as much, or even more so, than a science. Not only does the type of oak play a part in the effects it has on the wine, but other factors need to be considered too.
Top Picks for French Oak:
• Lewis 2015 Chardonnay
• Wrath 2013 Syrah
Top Pick for American Oak:
• Merlo 2014 Zinfandel
Besides the origin of the oak barrel, what are the other important factors that impact the oak influence on a wine?
The other important factors include the age of the oak, the level of the "toast", and the size of the barrel. The newer the oak barrel, the more oaky aromas and flavors will be imparted on the wine. By the fourth or fifth year of use, the flavors are negligible and the oak is termed ‘neutral’. Barrels are usually "toasted" during its construction either in an oven or with a flame and can be given a high, medium, or light toast. The higher the toast level, the more oaky aromas and flavors will be imparted on the wine. Lastly, the size of the barrel is significant, with smaller barrels producing a greater impact on oak aromas and flavors due to the wine having more surface area in contact with the barrel.
Relevant: Why are there different toasting levels of oak barrels?
Why are barrels the vessels of choice for the storage of wine anyway?
The use of oak has been prevalent in winemaking for at least two millennia, first coming into widespread use during the time of the Roman Empire. Over time, winemakers discovered that beyond just storage vessels, wine kept in oak barrels took on properties that improved it by making it softer, and in some cases, better tasting. Furthermore, the porous nature of an oak barrel allows some levels of evaporation and oxygenation to occur in wine, but typically not at levels that would spoil the wine. The evaporation allows the wine to concentrate its flavor and aroma compounds, and the small amounts of oxygen act as softening agents on the tannins of the wine. Lastly, the different origins of oak give winemakers great flexibility in fine-tuning the flavors, aromas, color and tannins they want in the finished wine.
Originally published in our Wine Press' Wine Wizard, Casey Flat Ranch Vineyards edition featured in our Gold Wine Club.