Not enough oak for you last time? Here’s some more on the topic of oak aging. Click here to read our first post on oak. In wine production, there are three main categories suitable for aging wine: French, American and Hungarian/Eastern European.

French Oak

The main reason for aging wine in French oak is the economical cost of the barrels. NOT. French oak starts in the high 3-digits (around $8-900/barrel. Many of them sell for closer to $2K and upwards.

[Excerpt: Let’s do some math. A barrel holds approximately 60 gallons, or 300 bottles. Already, that’s more than $2 added onto the price of the wine just for oak. The barrels can be used again but they’re influence on the wine decreases with each cycle.]

Back to French Oak. There are eight main forests used for barrel production. Most are pretty close to the center of France itself, except for Vosges, which is in the north east corner of France: Nevers, Allier, Trances, Centre, Vosges, Bertrange, Jupilles, and Limousin.

French Oak grain is tighter and therefore does not impart a very heavy flavor to the wines it holds. It is typically best used especially with more delicate wines, not to overwhelm the light natural fruit flavors.

American Oak 

American Oak is harvested from 18 states, with immense differences in location compared with France. Oregon is the only state oak is harvested in on the West Coast and most of the rest come from the Midwest and Appalachian region.

American oak grain is much wider and packs a bigger flavor to impart. American oak complements bigger styled, especially New World but not necessarily. Spain’s Rioja region is known for using American oak to stand up to its powerful Tempranillo varietal.

Hungarian Oak

Hungarian Oak is actually the same species as French, but costs significantly less. It’s even comparable to French oak in that the flavors it imparts to the wine are more delicate than that of American oak. Its flavor profile falls somewhere between French and American.

Of course, if a new barrel and a used barrel hold the same exact wine, the new barrel will taste significantly more tannic and oaky than the other. The reason? The common metaphor among wineries is that oaking a wine is like drinking tea from one tea pouch. The first time you use it, the tea is very strong, but each time you refill your cup with more hot water, the flavor loses power. If wineries say their oak is “20% new,” then 2 of 10 barrels are brand new, while the other 8 have been through more cycles of winemaking.

Toasting and Aroma 

Another big differences come from how the barrel was toasted. Included in the components of oak are Lignin, Cellulose and Hemicellulose. Lignin is a polymer part of the secondary cell wall of plants, and actually makes up up to one third of any given wood’s mass. Cellulose, which constitutes almost half of the mass, is basically a bunch of linked glucose, and is found in the primary cell wall. It’s where your printer paper comes from. Hemicellulose is the third component of wood’s make up but doesn’t serve a largely supporting role.

That was a lot of biology, sorry. The reason all this is important is that when the barrels are toasted, they break down into simpler substances.

These three components will essentially break down through toasting. Lignin, being the most influential and produces the vanillin aroma or at higher temperatures, smoky, spicy, and woody aromas. ETS Laboratories has a great diagram that summarizes the below compounds here.

Some common compounds found in wine due to oak influence and what aromas and flavors they manifest in:

-Lactones contribute fresh oak and coconut flavors and aromas which are found more in American oak. More toasting will actually decrease Lactones.
-Vanillin – Untoasted oak naturally contains vanilla. If less Vanilla flavor is desired, a higher toast can be ordered or it can also be eliminated by certain yeast if barrel fermented
-Eugenol and Isoeugenol – These two compounds contain a spicy clove aroma.
-Guaiacol and 4-Methylguaiacol develop from high-temperature toasting.  They both contain a charred aroma as well as spicy notes (only 4-Methylguaicol)
-Furfural and 5-Methylfurfural derive mostly from cellulose and hemicellulose and lead to the caramel flavors that develop during toasting.