CRUSH:
Oak: The Winemaker's Spice Rack
March
2008
To amateur imbibers,
the wine barrel may appear a mere contrivance of
the glorified process of winemaking—a quaint,
rustic old container that simply holds and transports
that liquid luxury for which so many descriptive
qualities and biological properties have been named.
But seasoned samplers and wise winemakers know
that the oak tree—father of that dull and
unassuming barrel—is as much of a magical
plant as the vine, and it’s almost equally
responsible for those fancy flavors and aromas
in wine.
Specially selected for the style of wine desired, and entrusted to bring juvenile
juice to smooth, sophisticated maturation, the barrel seals the deal that began
in the vineyard. And, as it turns out, the humble barrel has a history of careful,
measured cultivation rivaling that of the noble grape itself.
A
Tradition Aged in Oak
Our history teacher is a young, spry New Zealand
native who climbs about the barrel room at Domaine
Alfred in Edna Valley, producing sample after
contrasting
sample of oaked wine as if it were his personal jungle gym. Their winemaker
since 2006, Fintan (Fin) Du Fresne generously lends his lovely accent, fully-stocked
barrel “classroom,” and seasoned knowledge of barrels and blending
to our education.
The craft of wine barrel making, or cooperage,
is an ancient and largely unchanged art.
Since the barrel is responsible for not
only storage but fermentation,
oxidization, aging, and, consequently, flavor imprinting (which are all dependent
upon the amount of air that seeps through the pores of the wood used, or the
tightness of the grain)—the choice of wood is critical. Oak, as opposed
to pine or chestnut, turned out to provide the perfect environment in which
to incubate the special elixir due to its tight grain, strength, flexibility,
neutral smell and color, and desirable flavors and tannins. Fin explains that “because
of the oxidative processes going on, you get evaporation of alcohol through
the wood, and that really softens the wine.” Depending on the oak type
and the cooperage, the barrel also imparts to the impressionable wine some
of those familiar texture descriptors (structure, roundness, creaminess) as
well as unique oak flavors like clove, nutmeg, cinnamon, caramel, chocolate,
coffee, vanilla, coconut, spice, and other savory seasonings at various rates
and intensities.
The
French Legacy
Terroir and “varietal” play as much of a role in barrel making
as in winemaking. Certain species of oak (Quercus robur and Quercus sessilis),
particular forests, and even specific sections of the forests were identified
as optimal for wine barrel production. The majority of the barrels used in
winemaking today still come from just five forests in France, planted in Napoleon’s
day: Allier, Limousin, Nevers, Trancais, and Vosges.
French cooperages also set the standard for calculated barrel craftsmanship
precisely tailored to the needs and desires of a winemaker. “Basically
after they’ve selected and cut the trees down, they split the wood into
staves and age it anywhere from two to three years, outside. The rain’s
on it, the sun’s on it, and it turns from green sappy wood to something
dry, shrunk, cured,” Fin details. After that aging period, coopers toast
the wood to bend it into shape, a process which “caramelizes the tannins
of the oak” and affects the intensity of the flavors imprinted on the
wine.
A Whole New World of
Wine
With a monopoly on both the wood and the construction of barrels, the price
of French oak barrels has soared to $500 – $1000 a pop, causing many
to look to newcomers in the industry: American or Hungarian oak cooperages.
Due not only to the difference in species (Quercus alba), but obviously
to the change in terroir and craftsmanship, early American barrels imparted
overwhelming flavors that covered the fruit. But as the U.S. coopers learned
to replicate French methods more closely through open-air curing and gradual
toasting, the quality increased dramatically. The biological differences, however,
remain: fast-growing American oak has more sugar and wider grains, resulting
in a more powerful punch of vanilla, coconut, and sweet spice as compared to
the subtle, savory effects of French oak. One is not better or worse than the
other, Fin says; it’s simply one of those exciting opportunities for
a winemaker to imprint the wine with his own style.
Domaine Alfred’s program, for instance, is mainly French oak with a little
bit of Hungarian. “We just find that the structure and the subtlety that
is imparted by French oak suits the style of wines that we do,” says
Fin. “We do mainly Burgundian varietals—Chardonnay and Pinot Noir;
they’re often overpowered by all the compounds and extraction that we
get from American oak.” While an American barrel might override the softer
spoken Pinot Noir, it would pair well with Zinfandel or Rhône varietals
from Paso Robles, for example, where some wineries are “looking for a
big, jammy, sweet wine.”
Gauging
the Impact
The greatest indicator of the effect any type of barrel will have is its age.
A new barrel, Fin says, has an “inversely logarithmic curve for extraction.” In
simpler terms, it has more flavors available for extraction than does an older
barrel. For that reason, winemakers can balance the oak-impact by using a percentage
of older, or “neutral barrels.” He says they use higher percentages
of new oak on their naturally intense and flavorful grapes designated for Domaine
Alfred’s Califa line of wines. “Our Califa Chard is typically big,
bold, buttery, creamy—so we use specific barrels for the lots that we
think will go to Califa to enhance that creaminess and butteriness.”
Obviously, much care and serious consideration go into a winery’s selection
of the material that can so indelibly affect the taste of their wine. “There’s
a lot of variables and it’s a little much to take in at first, but over
time you get a feel for what works best with different wines,” Fin says. “I
guess the important thing is you have some diversity in your cooperage so that
when it comes to blending, you’ve got this spice rack of flavors that
you can choose from.” And therein lies the art (and the fun) of winemaking:
taking mere juice and spicing it up with human craft, style, and a little bit
of good, old-fashioned oak.
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