The anatomy of a wine barrel
Posted by Colleen | Wine News | Posted on December 21st, 2010
Oak barrels are like a winemaker’s spice rack…
…that was the analogy that someone once told me, when trying to explain what purpose the oak barrels served in making wine.
I thought that line was genius, because truly, oak barrels are to a winemaker, as a spice rack is to a chef. (Is anyone else having SAT analogy test flashbacks?)
My curiosity about oak began when we got barrels delivered just before harvest and they had been shrink-wrapped. I had never seen brand-spankin’ new barrels, let alone covered in plastic, so I asked that the deal was with them. Where they being preserved? Was the oak influence escaping via contact with the air? Come to find out, it’s nothing, just the way they are packed out. It’s the same, non-existent reason some barrels have that red stripe around their middles (Apparently that’s just for aesthetics. Who knew?)
I sat down with our winemaker, Richard Sowalsky, to have him explain what the oak of choice is around Clos Pegase…I had heard we used 100% French oak, but had no idea what that brought to the table. What makes French oak different than American? Or Hungarian? And exactly why does new oak-versus-old oak play a part?
Richard helped set me straight on the intricacies of all things barrel.
Different types of oak have different types and amounts of tannin, which is a component of wine. A very important one, in fact. Those tannins contribute to mouthfeel and body in wine, which is illustrated nicely in our Cab Sauv, Pinot and Chardonnay, among other varietals.
There is also a diversity of oak grain offered by the various types of oak. The grain size of the barrel helps to control the exposure of oak to the wine. With a smaller-grained oak barrel, the wine will receive a slower exposure to the oak influences. Larger-grained barrels exposure the wine to oak more quickly over time, and are most useful for wines aged for a shorter time in barrel, such as Chard or Pinot.
Then there is the region of the oak to consider. I found out in talking to Richard that while Clos Pegase traditionally used 100% French oak for almost all varieties, we do use a small percentage of American oak for our Merlot and Pegaso wines, because it brings some special characteristics to the winemaking table.
American oak, because it has more lactones (a chemical compound of sorts) offers hints of toasty, sweeter flavors like coconut and marshmallow; this species of oak also has naturally low levels of tannins. French oak, on the other hand, brings a whole new set of flavors and aromas to the party. Characteristic of French oak are baker’s spices (vanilla, cinnamon, clove, etc.) along with roasted coffee bean and chocolate characteristics. Hungarian oak rounds out the Winemaker’s Spice Rack, though it is not currently used at Clos Pegase. Hungarian oak is known to have a bit more of a kick since it imparts more peppery spice notes.
One important area of note is toasting level, which is essentially the controlled baking of the inside of the barrel over a fire. Toasting will move the flavors of the wood from lighter and spicier to darker and more deep and roasted, with a big impact on the wine. We use a variety of toast levels at Clos Pegase to enhance the wine and add complexity.
There is also the new-vs.-old oak to consider–as in, new barrels impart flavors more intensely than used barrels. The oak characteristics will, over time, get “leached” out of the barrels and after each use, the oak influence becomes more and more tame until there may not be enough to do the wine any good. It’s usually around the third or fourth go with the barrel that it no longer brings any oak influence to the party and at that point the barrel goes out of circulation.
Barrel size also plays a part in imparting oak characteristics on the wine. It would make sense that the smaller the barrel, the more concentrated the oak influence would be on the wine, since there is relatively more barrel surface touching the wine in these smaller casks.
One of the most common questions we get asked when we head into our caves is, “how much wine will a barrel produce?” and that answer, obviously, is that it depends on the size of the barrel. For the most part, we use Bordeaux-style barrels that hold 59 gallons or Burgundy style barrels that hold 60 gallons, or about 25 cases of wine. But for our Sauvignon Blanc, we use larger oak barrels called puncheons to impart just a touch of oak (just enough to balance out that acidity down so it’s not widely askew of the other components of wine). These sauv blanc barrels are noticeably larger and hold 79 gallons, or about 33 cases of wine.
Our winemaking team matches the barrel type with the wine in order to create the balance of all wine components and having different styles of oak to play with help make that possible.
