We’ve come a long way since oak was merely a storage and maturation medium for wine. Judging from an all day seminar that Taransaud organized in London for the Institute of Masters of Wine, its role today is second only to the grapes themselves. The seminar was divided into two parts: a morning that considered individually many of the parameters that determine the effects of oak; and an afternoon looking at innovations to respond to changes in modern winemaking. Here’s a report on the morning; the afternoon will follow.

The background according to Henri de Pracomtal, Chairman of Taransaud, is that use of new oak is declining, down to 85% instead of a mandatory 100% when the vintage isn’t up to it in Bordeaux, although typically staying more or less around a third new, a third one year, and a third two year in Burgundy. The use of 200% oak (successive use of new barrels) is “dead.” There’s been significant backing off from new oak in the New World. The focus here was all on oak barrels,  although Taransaud also own Canton in Kentucky, where other formats are used. When they bought Canton, Henri was horrified to see oak chips, and wanted to stop their production, but “look at the profit margin” they told him. “Oak chips are for short term aromatics rather than long term élevage,” he says. The seminar was entirely about the effects of different barrel regimes on wine quality and style.

A long list of aroma and flavor compounds that are extracted from oak made it clear in a talk from Taransaud’s oenologist, Nicolas Tiquet-Lavandier, that the effects are profound. Considering how long oak has been used, it seems surprising that new compounds are still being discovered. I was also surprised that the role of oxygen loomed so large, with discussion about the porosity of the oak, entry between the staves, and through the bung. I thought it had now been established that basically all oxygen enters through the bung (which should mean there’s much less since the change to the new silicon bungs).

The heart of the seminar was a series of comparative tastings with wines that had been specially vinified under different conditions. The results of comparing French, Hungarian and American oak were fairly predictable, with a strong contrast between the toasty vanillin of Château Puygueraud (Côtes de Francs) 2011 in French oak and the stronger aromas of coconut from American oak. Since French and American oak are different species of trees this was not surprising, but the difference between French and Hungarian, which are the same species, was pronounced: the French oak gave a refined impression to the wine, the Hungarian was somewhat coarse. This emphasizes the effect of growth conditions on the oak: it’s colder in the Hungarian forests and the trees tend to be smaller. This links in to a change in the way tonneliers in France handle their sources – there is much less emphasis on individual forests, and more on the grain of the individual wood. “Within a forest is not a unique location. This is why we at Taransaud have gone our of the forest, we blend forests, the grain is very important, the tighter the grain, the more slowly the wine matures,” says Henri.

I was quite fooled by the blind tasting to test the effects of duration of seasoning. The wood at Taransaud is air dried by exposing staves in the open. A critical element is the need for rain and humidity in the first six months, which is becoming a concern in view of reduced rainfall in some years. The seasoning at first extracts compounds from the oak – this is crucial for reducing bitterness – and then adds other compounds as fungal infections occur; Henri likened this to maturation of cheese. I placed the three samples of Château Phélan Ségur 2010 in order on the assumption that more seasoning gives more subtle results, but this turned out to be too simple. Certainly the sample from 12 month seasoned French oak seemed a bit harsh compared to the others, but the 30 month seasoning seemed to produce a better balanced and more subtle wine than the 55 month seasoning, which had stronger wood spices. A similar test of American oak with the Swanson Vineyards 2010 from Napa Valley gave an overwhelming impression of coconut and dill on the 24 month seasoned sample, still pretty powerful and pungent with 36 months, but finally damped down a little with 48 months. Here longer is better. I was reminded that Paul Draper at Ridge, who uses American oak for the Montebello Cabernet, told me that American oak has a bad reputation not because of its intrinsic properties but because it’s not treated in the same way as French oak (it’s usually sawn instead of split and not air dried).

Blind tasting to test the effects of time spent in barrels also fooled me, as I was working on the assumption that impression of oakiness would be in direct proportion to time in oak (especially allowing for the fact that shorter time in oak would be followed by time in bottle). But Phélan Ségur 2010 showed the most vanillin, and even a touch of coconut, after 8 months in oak, still a touch of vanillin after 16 months in oak, but the cleanest and purest expression of fruits after an intermediate 12 months. However, the 16  months showed overall the most classic and best balance. Clearly this is not a simple matter of absorption into the wine with time, but of more complex interactions. For example, ellagitannins increase with up to 250 days in barrels and then decline.

The percentage of new oak at least was predictable: new oak was quite evident on the nose and palate of a Château Branaire-Ducru example from 2010, with an example that had been matured in second year oak showing more direct and purer fruits; but the blend had more weight, and was softer, rounder, and more complex. An interesting demonstration of classic balance obtained by not going to extremes.

Along the way, a panel of four winemakers commented on their impressions. With a range of different backgrounds (Sandrine Garbay from Yquem, Edouard Labruyère from Jacques Prieur, Peter Sisseck from Dominio de Pingus, and Stephan von Neipperg from Château Canon-la-Gaffelière), it was not surprising that their opinions differed. In a demonstration of how individual palates can agree or disagree, I was interested to see that there was one winemaker with whom I agreed on everything, one with whom I disagreed on everything, and two who were in between. I know whose wine I’m buying in the future.