The Van Duzer Corridor AVA, a sub-appellation of the

Willamette Valley AVA The Willamette Valley AVA ( ) is an American Viticultural Area which lies in the Willamette Valley of Oregon. The AVA is the wine growing region which encompasses the drainage basin of the Willamette River. It stretches from the Columbia Riv ...

located within

Polk County, Oregon Polk County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 87,433. The county seat is Dallas. The county is named for James Knox Polk, the 11th president of the United States. Polk County is ...

, in the United States, is an

American Viticultural Area An American Viticultural Area (AVA) is a designated wine grape-growing region in the United States, providing an official appellation for the mutual benefit of wineries and consumers. Winemakers frequently want their consumers to know about th ...

approved by the

Alcohol and Tobacco Tax and Trade Bureau The Alcohol and Tobacco Tax and Trade Bureau, statutorily named the Tax and Trade Bureau and frequently shortened to TTB, is a bureau of the United States Department of the Treasury, which regulates and collects taxes on trade and imports of alcoh ...

on December 13, 2018 and effective January 14, 2019. The Van Duzer Corridor AVA lies entirely within the established Willamette Valley AVA and covers approximately . When the petition was submitted there were 17 (now 18) commercially-producing vineyards covering a total of approximately , as well as six wineries (now 9), within the AVA. The distinguishing features of the Van Duzer Corridor AVA are its

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary s ...

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologica ...

, and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

Topography

Topography is characterized by low elevations and gently rolling hills. The low elevations allow cool breezes to flow relatively unimpeded from the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

, through the

Oregon Coast Range The Oregon Coast Range, often called simply the Coast Range and sometimes the Pacific Coast Range, is a mountain range, in the Pacific Coast Ranges physiographic region, in the U.S. state of Oregon along the Pacific Ocean. This north-south ru ...

, forming a wind corridor gap known as the

Van Duzer corridor H. B. Van Duzer Forest State Scenic Corridor is a scenic driving route along Route 18 in Lincoln, Tillamook, and Polk counties in the U.S. state of Oregon that passes through a forested corridor. The Van Duzer Corridor stretches from northwester ...

. The western end of the Van Duzer Corridor wind gap is narrow and squeezed by high elevations to the north and south, leaving little room for

viticulture Viticulture (from the Latin word for ''vine'') or winegrowing (wine growing) is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of ''Vitis vinifera'', the common grape vine, ran ...

. However, the eastern end of the Van Duzer Corridor wind gap, where the Van Duzer Corridor AVA is located, features the same low elevations and rolling hills as the western portion, with the distinction of having a wider area suitable for vineyards. Within the Van Duzer Corridor AVA, the elevation does not impede the eastward-flowing marine air, allowing higher wind speeds to flow through. In contrast, the surrounding regions all have higher elevations.

Climate

Climate is characterized by consistent high wind speeds and low cumulative

growing degree-day Growing degree days (GDD), also called growing degree units (GDUs), are a heuristic tool in phenology. GDD are a measure of heat accumulation used by horticulturists, gardeners, and farmers to predict plant and animal development rates such as the ...

(GDD) accumulations. The consistently high winds in the AVA contribute to thicker grape skins, and raise the levels of

phenolic compounds In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds ...

in the fruit. In contrast, the wind speeds to the north and south southeast of the AVA are slower. The Van Duzer Corridor has lower GDD accumulations than surrounding regions to the north and southeast, indicating that its temperatures are generally cooler. The cooler temperatures ripen the fruit slowly, creating a longer hang time than for the same grape varietal grown in a region with higher GDD accumulations. The longer hang time contributes to a reduced acidity level.

Soils

Soils are primarily uplifted marine sedimentary loams and silts with

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Al ...

overlay, as well as some uplifted

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...

. The soils are typically shallow, well-drained, and have a bedrock of

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

. The high

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel wh ...

and

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...

levels in the soils balance the overall pH level of the soil by buffering against a sudden increase or decrease in soil pH. The buffering effect is beneficial to vineyards because it boosts the ability of the soils to maintain a stable pH level. In contrast, the soils immediately outside the northern and western boundaries contain soils from different soil series. Farther north and west, the soils contain higher concentrations of basalt and other volcanic materials. In contrast, east of the Van Duzer Corridor AVA, within the

Eola-Amity Hills AVA The Eola-Amity Hills AVA is an American Viticultural Area located in Polk County and Yamhill County, Oregon. It is entirely contained within the Willamette Valley AVA, and stretches from the city of Amity in the north to Salem in the south. ...

the soils contain larger amounts of volcanic material than the AVA. Additionally, south of the AVA, the soils contain large concentrations of Ice Age loess, which is not found in the Van Duzer Corridor AVA.

References

External links

Van Duzar Corridor AVA
{{Portal bar, Geography, Oregon, Wine 2019 establishments in Oregon American Viticultural Areas Geography of Polk County, Oregon Oregon wine Willamette Valley