In one of the most felicitous phrases in
wine writing, the great Hugh Johnson once called vineyard soil “the unseen dankness where the
vineroots suck.” It is in this deep and dark place where many people
believe wine is really made.
Here in the Pacific Northwest, some of the most cataclysmic geologic
forces ever to scar the face of the earth have created unique terraforms
that profoundly influence the character of our wines and helps distinguish
them from wines grown on other geologic foundations. Understanding the
nature of our soils and their relationship to our wines can only help
us better appreciate the special qualities of Pacific Northwest wines.
The Theory of Terroir
It is common these days to hear a lot of
loose talk about “the
terroir of Oregon” or the “terroir of Washington,” (and
even the terroir of this vineyard or that site) but little is ever written
to define what is meant by terroir.
“Terroir is an overused word,” says Patty
Green of Patricia Green Cellars in Newberg, Oregon, “but to me it describes what
different soil types deliver into the wine—for me soils play a
huge part in the flavor of a wine.”
The idea that it is the character of the
soil that is most responsible for the character of the wine is, like
most great concepts in winemaking,
primarily the invention of the French. But here in America, we have tended
to radically simplify their complex and nuanced concept of terroir, and
allowed it to become a shorthand term meaning generally “the impact
of the land and soils on the vine and wine.”
And since the Pacific Northwest has landforms and soils that are distinct
from other regions (California, for instance), it would seem to follow
by the theory of terroir that the wines we produce would be distinctive
as well.
After all, it only stands to reason: grapevines
depend upon the soil for their nourishment, and it is because of that
nutriment that they
can fulfill their reproductive imperative, the ripening of fruit. The
compositional qualities of different soils—their varying mineral
and nutritional contents—must surely influence the way the vine
grows, and consequently the characters of the fruit that vine can ripen.
And so, it would seem, it does!
The Willamette Valley Soils
Perhaps the place in the Northwest that most
clearly shows how soils can impact wine character is Oregon’s Willamette Valley. Here the
cataclysmic forces of earth’s geology (see sidebar) have resulted
in two predominant soil types upon which Pinot noir is planted: volcanic
and sedimentary.
At the mid- and higher elevations of the
hills and bluffs that rise from the floor of the valley, volcanic soils—typically
a distinctive red color—are generally found that contain decayed
basalt, clay, and occasional interloping rocks and boulders delivered
here by the Missoula
Floods (an ancient series of massive floods that periodically swept through
what is today the Columbia River basin). The most commonly recognized
volcanic soil type is Jory, which tends to be between 4- and 6-ft. deep,
overlaying a basaltic bedrock base. This is the predominant soil type
from the prime Pinot producing areas of the Dundee and Eola Hills.
Artist's Idea of the Glacial Lake Missoula, by Byron Pickering
Sedimentary soils (some of which are marine in origin, and some which
were deposited by the Missoula Floods) are found at lower hill elevations
in the north Willamette Valley, along the foothills of the Coast Range,
and in hills around Eugene, in the south Willamette Valley. These soils
consist of yellow-brown-red silty-clay and loam, usually overlaying sandstone
bedrock by 3- to 5-ft. This is the soil type often generically referred
to as WillaKenzie (though a recent reclassification of sedimentary soils
has changed the technical nomenclature). Pinot noir is planted on the
sedimentary soils surrounding the Dundee Hills, the Chehalem Hills, Ribbon
Ridge, Coast Range foothills, and other locations.
Over the years, winegrowers have come to see that the broad character
of Pinot noir is different depending upon which if these two soil types
it was grown in. Taking a broad view, Pinot from the volcanic
soils tends to show big cherry and brambly red berry flavors along with
accents of
flowers and spices. Winemakers have noticed as well that these wines
are often very consistent in their character, from the time they are
picked, through fermentation and ageing, and even in the bottle.
Sedimentary soil Pinot noir, on the other
hand, tends to display a darker fruit aspect, with more blackberry
and plum nuances, as well as additional
notes of earth, pepper, and minerals. Also, these wines tend to evolve
more as they age, displaying subtly different aspects as they evolve.
Patty Green, for one, attributes these different
styles to the different soils.
“After our first vintage,” working with sedimentary
soil vineyards, she says, “we clearly had a feel that there was
something different going on with the wines from the marine sediment
soils as opposed to the volcanic soils we had in the cellar previously.
It was really exciting to see how these wines each had their own character,
and how the taste of the soil was delivered in each of the wines.”
The Columbia Valley Soils
Washington’s Columbia Valley appellation
(encompassing the Yakima Valley, Red Mountain, and Walla Walla AVAs)
was perhaps even more dramatically
impacted by the Missoula Floods then the Willamette Valley was. However,
the Columbia Basin experienced much more volcanic activity, and the topography
and soil composition is thus quite different than in Oregon.
The bedrock of most of the Columbia Valley
consists of massive basalt flows—in fact, the largest lava flows on earth—that
were deposited by massive volcanic eruptions. Over the eons, the force
of
the Missoula Floods eroded huge channels and cataracts in the landform
and deposited layers of sediments across the Columbia Plateau. As geologic
time progressed, wind and other forces eroded rocks on the high points
of the plateau, and helped re-arrange and re-deposit sediments across
the area.
Today, much of the region is covered by a
thick layer of loess (fine grained calcerous silt) that provides the
topsoil for much of the region’s
best vineyards. But the actual composition of the loess varies considerably,
and accounts for distinctive wine qualities, even in nearly contiguous
vineyards.
For instance, two of the most famous Washington
vineyards are separated by only about 500 yards, yet each produces
wines of distinctly different
characters. Ciel du Cheval vineyard sits on top of an ancient gravel
bed, with a thin layer of weathered topsoil. The red wines grown here
are well-known for their elegance, complexity, and softness. Nearly next
door, Klipsun Vineyard’s soils are much deeper, sandier, and with
more loam. Their red wines are famous for displaying bigness, power,
and concentration.
Connoisseurs of Washington’s Cabernet sauvignon and Merlots will
undoubtedly have compared their relative qualities with the great wines
of the same varietals from California. If terroir has any reality, the
differences in overall character (winemaking expertise aside) can be
chalked up to the differences in soil compositions. Washington’s
relatively arid, calcerous, and sandy soils are said by many to impart
mineral notes, depth, and softness that are different from wines made
in California’s more fertile soils.
In the end it may not be quite fair to say that the great wines of the
pacific Northwest taste like dirt, but it is certainly the dirt of the
Northwest that makes great wines!
From the USDA:
The Jory series soil consists of very deep,
well-drained soils that formed in colluvium derived from basic
igneous rock.
These soils
are in the foothills surrounding the Willamette Valley. They have
been mapped on more than 300,000 acres in western Oregon.
They are named after Jory Hill, Marion County, Oregon.
Jory soils generally support forest vegetation,
dominantly Douglas fir and Oregon white oak. They are very productive
forest soils. Many areas have been cleared and are used for
agricultural crops. The Jory soils and the climate of the Willamette
Valley provide an ideal setting for the production of many crops,
including Christmas trees, various berries, filberts (hazelnuts),
sweet corn, wheat, and many varieties of grass seed.
The soils
are suitable for the grapes used in the expanding wine industry.
Growing urbanization of the Willamette Valley is resulting
in a
great deal of pressure for development in areas of the Jory
soils.
Reprinted with permission USDA
Terroir - A
French concept that is difficult to translate, but which
is frequently used in wine discussions. The full
term, gôut de terroir, generally means the total characteristics
of a vineyard location that combine to create a unique “taste
of place.” The idea is that each grape growing site
has its own particular set of circumstances—elevation,
aspect, topography, soil composition, wine, rail, sunlight
hours, etc.—that combine to create a unique character
that can be tasted in the wines grown from that spot. Further,
terroir is neither good nor bad, but is indigenous to the
spot where the grapes were grown—it is just as possible
to have a terroir that is unpleasant as it is to have one
that is good.
The idea, then, is for
the grower to find terroirs that produce appealing wines.
Unfortunately, most people
feel that terroir doesn’t truly show itself in a vineyard
until the vines reach a certain age, or until the roots of
the vines grow deep enough to be in contact with the bedrock.
Though a controversial concept in American winegrowing, ity
has proven particularly appealing in the northwest.
The most commonly
recognized volcanic soil type is Jory,
which tends to be between 4- and 6-ft. deep, overlaying a basaltic
bedrock base. This is the predominant soil type from the prime
Pinot producing areas of the Dundee and Eola Hills.
What About Climate?
Skeptics of terroir point out
that the effects of climate—sunlight,
rainfall, temperature, wind—have at least as much,
if not more, to do with the ultimate quality of grape growing
as does the soil in which the vine is planted.
They have a point!
It would be difficult indeed
to declare that there is an “ideal
soil” for the growing of winegrapes—there is
almost no soil type, given proper drainage, where vinifera
can’t be grown. Yet it is quite easy to define an “ideal
climate” for different winegrape varietals, Indeed,
vinifera grapes simply can’t be ripened (or even grown
at all) under many common climate conditions.
So climate most definitely does
play a pivotal role in determining the quality of wine.
Just look at how Pinot noir grown in
Oregon’s cool climate regions consistently delivers
a different character wine from Pinot noir grown in California’s
warmer climate areas.
But the importance of climate does not invalidate the importance
of soil in determining the character of wine. The fact is,
the full meaning of terroir encompasses both the soil and
the climate (as well as, truth be told, the culture and even
psychology of the winegrower and winemaker).
It is a misunderstanding of the
concept of terroir that leads people into the false dichotomy
of “soil is more
important” or “climate is more important.” Actually,
they both are more important—and the best Northwest
winegrowers constantly strive to understand and use the myriad
ways the weather and dirt interact with the vine!
Titanic Tectonics
of the Northwest
The geology and topography of the Pacific Northwest are
the result of some of the most titanic tectonic events ever
detected. Nowhere else on earth have geologists found evidence
of such gargantuan volcanoes and floods as is found in what
is today the wine country of eastern Washington and northern
Oregon.
For instance, the bedrock of
the Columbia Valley consists of an estimated volcanic eruption
volume of 3,000 cubic kilometers
of what is today basalt rock. As a comparison, the eruption
of Mt. St. Helens released approximately one cubic kilometer
of material—and we think that was big! The erosions
and uplifts of this material over the eons has resulted in
some of the largest swaths of sedimentary soils on the continent.
The Missoula Floods were equally
enormous. Geologists estimate that the ancient ice dam
that held back the glacial Lake
Missoula (formed during the last Ice Age along the Clark
Fork River in northern Idaho)) was about 1,968 feet deep.
When that dam broke (as it repeatedly did over time), it
sent approximately 2,500 cubic kilometers of water across
the Columbia Plateau and down into the Willamette Valley.
The water raced at a speed and volume that equaled 10 times
the combined flows of all the world’;s rivers today—that’s
a heck of a lot of water! It has been estimated that the
depth of the flood in the Willamette Valley may have been
as high as 400-ft.
(Thanks to the article “Terroir of the Red Mountain
Appellation, Central Washington State, USA” by Lawrence
D. Meinert and Alan J. Busacca, published in Geoscience Canada,
December 2002.
For more about the Missoula Floods and
the formation of the Columbia Gorge, see our article:
