Agriculture Reference
In-Depth Information
Mayacamus
Mountains
Vaca Mountains
Napa River
Alluvial/colluvial fan
All
u
vial ri
d
e
posits
ver
Oceanic
crust
Volca
n
ic deposits
Marin
e
sediments
Figure 9.9
An east-west section through the strata of the Napa Valley, California (redrawn from
Livingston 1998).
Mayacamas Mountains in the afternoon. Yields are low (ca. 5 t/ha), and the de-
gree of stress suffered by the vines as the fruit matures produces intense flavors.
On the western side, the Rutherford AVA is renowned for its Cabernet Sauvi-
gnon, and distinctive wines are also produced in the Oakville and St. Helena AVAs
to the south and north, respectively. Similarly, Cabernet Sauvignon wines from
the Stag's Leap AVA on the eastern side have a distinctive character attributable
to the volcanic parent material of the alluvial and colluvial soils found there (Liv-
ingston 1998).
The emphasis on soil as an important component of the
terroir
of ultra-
premium and superpremium Napa Valley wines has come fairly recently. Previ-
ously, Winkler et al. (1974, p. 74) wrote that “varieties of the highest quality pro-
duce excellent wines when grown on a number of different soil types. Thus, the
difference in the character of wines can hardly be attributed to specific soil types.”
These authors argued that the principal factor controlling fruit quality in Cali-
fornia was the mesoclimate (expressed by heat summation), through its influence
on the sugar:acid ratio, total acidity, tannin content, and other minor constituents.
Grape variety was the determinant of inherent characteristics, such as aroma and
flavor. But the current view is that quality depends on how well the grapes are
grown and the wine made, whereas the character of a particular varietal wine that
has been well made depends on soil type and other factors such as mesoclimate
and topography, including aspect (Elliot-Fisk 1993).
The Willamette Valley of Oregon
9.6
Location, Climate, and Geology
The Willamette Valley AVA is relatively small, production-wise, but it has estab-
lished a reputation for its Pinot Noir wines. Chardonnay, Riesling, and Pinot Gris
9.6.1
