The Effects of Oak Barrels on Wine

One of the most controversial topics among professionals of wine is the use of oak barrels and the taste that results from it.

I was recently visiting a cooperage in Burgundy and I was impressed by the development and the growing sales of this industry.

The following pictures show the process of barrel-making. Still done by hand, the work of these men is impressive and very precise. I don’t suggest visiting such a place before lunch like I did, as the chocolate/vanilla/bread smells coming from wood-heating are delicious!

It seems like more and more winegrowers want to use barrels to make their wine. A brand new barrel (of French oak) costs on average 650€ ($800). However, prices will keep increasing over the years due to the growing demand of trees. In other words, affording high quality new barrels will become a privilege only the richest estates will have.

French oak is considered the most desirable wood for making wine barrels. Most of it comes from one or more of the forests planted in the days of Napoleon for ship building. Five of those forests are primarily used for wine barrel making. Tronçais is considered one of the very best forests because of the quality of its wood.

There are only three types of oak on the planet that can be used for barrel-making and one of them is the American white oak. Cheaper than the French one, the best wineries rarely resort to it as it gives strong coconut/chocolate aromas to the wine, compared to the much more neutral French oak.

Certain wineries opt for a different and much cheaper option, they put wood chips in wine in order to flavour it…

All of this raises an important question, what’s the purpose of aging wine in oak barrels? 

Unlike what many people think (even some professionals), the purpose of aging wine in a new barrel is not to give a certain taste to the wine. It has actually nothing to do with aromas or flavors.

A new oak barrel is “breathing”. Millions of little pores in the wood will allow a consistent exchange of oxygen between wine and the barrel. This is called micro-oxygenation. After 3 or 4 years of using the same barrel, these pores get clogged by wine and there is no more exchange going on. Thus, a barrel has less influence on wine each and every year. This is why the richest wineries renew their stock of barrels frequently. Also, when a winegrower explains that he lets his wine age in 8 year old barrels, remember that it doesn’t really affect it and that a stainless steel vat would probably give the same result.

The main purpose of barrel micro-oxygenation is to refine the texture of the wine  and to polish its body. Unfortunately, not all wines need to spend time in a barrel. Some wineries let their wine age in barrels for too long, or use a bigger percentage of new barrels than they should. It results in raw wines filled with wood tannins. Such a wine is often charming on the nose with vanilla or coffee aromas. However, on the palate, the wine might feel a little dry, tannic, and sometimes taste like a wooden board…

It is very important to understand that only a few wines, (the most structured, concentrated and balanced) tolerate a long aging in oak barrels. Basically, these are the wines that need to be kept in a cellar to mature.

This is why I’m often very critical with wood in some of my articles. Oak barrels have become a marketing and selling point. The vocation of wood is to disappear, to blend into the wine. Like spices with food or makeup with women, it should embellish without deforming the original.

Unfortunately, in too many wines, wood aromas and tannins crush the grape’s. It is then more of a wood liquor than wine…