At the southern edge of the Calchaquí Valley, in the town of Tolombón, the malbec vines are over half a century old. Each year at harvest (our spring) they select only grapes from the best plots for a wine called Atypico (91 pts – Atkin).

After fermentation in stainless steel, the wine ages 18 months in oak.

But not just any oak.

Atypico sits in ultra fine grain barrels from Vicard, of the Cognac region, the last of the French artisan tonneleries (cooperages). According to Julien Miquel, they are the best coopers in France.

Calchaquí winemakers tend to split down the middle on whether oak is appropriate for extreme altitude malbec. At Raúl Dávalos’ Tacuil, there was a time when suggesting it might get you kicked off the property (at best). On the other hand, if you follow the historical roots of Calchaquí winemaking far enough back, you run into France, an unrepentant bastion of oak.

We’ll leave the debating to the winemakers.

Instead, this week we’ll ask “why do winemakers use oak at all?”

More on that in a moment. But first… never pair a Riesling with oysters. This week, we revisit Julien Michel's explanation of “aromatic” versus “neutral” whites… including why you’d never say a red wine is aromatic… how to properly pair those aromatic whites… the ‘magic’ white wine combo that wins every time… and more...

Do Calchaquí Winemakers Hate Oak? (Cont’d)

In the 5th century BC, Greek historian Herodotus described Mesopotamians transporting their wine in containers made of palm wood. The Greeks were still moving their vintages around in clay amphorae with a layer of olive oil on top to stop oxidation.

Clay has its merits. In Eastern Europe, they still store wine in giant clay qvevri. In a clay container, the wine comes into contact with tiny amounts of oxygen – a process called micro-oxygenation. (The oxygen tempers the wine’s tannins.)

But clay also breaks.

The Romans pioneered oak barrels. Eventually, winemakers noticed that long hauls in oak barrels changed the flavor and mouthfeel of their vintages.

Winemakers today continue to use oak to modulate flavor, color, and mouthfeel. Micro-oxygenation rounds out the tannins. Phenols in the wood make the wine darker while adding notes of vanilla, tea, or spice (and sometimes dill). The pores in the wood also allow a small amount of wine to evaporate, concentrating its flavors.

Using oak is a bit of an art to itself. Its effect on wine will depend on the timing (where oak enters the process), the type of oak, and the type of barrel. For example, fermenting in oak tends to prevent its flavors from entering the wine (yeast neuters phenols). That’s why many winemakers ferment in stainless steel, then transfer the wine to oak for aging (which is the case for Atypico).

Choosing the right oak comes down to the wood grain, which controls the exchange of oxygen, evaporation, and oaky flavors. Until the first world war, the French used oak from the Zemplén Mountains in Hungary. The tight fine grain kept the flavors subtle and oxygen seepage slow. The Italians, too, favor a less aromatic oak from Slavonia, in eastern Croatia.

You’ll hear critics sometimes refer to “toast” in a wine. That’s an oak thing. Making oak barrels requires seasoning and bending hand-cut staves. The method used will influence the amount of “toast” in the barrel, not just because you might get a light note of burnt toast in the wine’s aroma, but also because the process affects micro-oxygenation, and therefore the degree to which the tannins soften.

Traditionally, seasoning involves simply letting the oak staves sit outside for about 24 months. A speedier process uses kiln drying, the drawback (or benefit for some) being that the oak loses less of its phenols in the process. A wine stored in kiln dried oak will come out with more intense oak flavors (and, perhaps, more toast).

Once seasoned, the staves are heated over an open fire to bend them into the barrel shape (more toast). An alternate method uses a steam tent (less toast).

There are two main categories of wine barrel – regular and enormous, with a few variants on each in between.

In Bordeaux, they favor “barriques,” the classic wine barrel you’re picturing in your head right now. Barriques are small at 225 liters and don’t last long (maximum 5 years). Burgundy and Cognac use slightly larger variations on the barrique. In Italy (and some parts of France), the barrels are over ten times larger. The Italian “botti” (and its French cousin, the “foudre”) ranges from 1,000 to 30,000 liters. When you hear about Barolos aging for ten years before release – they’re doing so in botti, not barriques. Botti last 25 years or longer.

You’ll hear winemakers specifically state that they use “new” or “used” barrels for such and such vintage. A new barrel will have more flavor to impart. A used barrel will have less. Over time, the wood simply runs out of phenols. The grain also stops letting in enough oxygen. The typical barrel gets 3 to 5 uses. Then, the funeral pyre.

Until next time,

The Wine Explorer

Bonner Private Wine Partnership