What’s different between Oregon Wine Region and Washington?

Recently I have been thinking differently about wine regions. Instead of thinking about what makes the region distinctive, I’ve been trying to think more clearly about how to compare and contrast different regions that make wine.  One question I asked myself was what is the difference between Oregon and Washington in the US.

Well, here’s my stab at a sensible answer! Predictably, I have focused on soils, climate, weather, and varieties to help my thinking.

Climate

Oregon:

Primarily a cool, maritime climate, especially in the Willamette Valley, influenced by the Pacific Ocean, with cool, wet winters and mild, dry summers.

The Cascade Mountains create a rain shadow effect in some parts of the state, but overall, Oregon’s climate is cooler and more temperate, which is ideal for cool-climate varieties like Pinot Noir and Chardonnay.

Southern Oregon AVA has a slightly warmer, more Mediterranean climate, and therefore sometimes producers grow varieties like Syrah and Tempranillo.

Washington:

A continental climate prevails, particularly in the Columbia Valley where 99% of Washington’s wine is produced. The state is largely shielded from the Pacific Ocean’s influence by the Cascade Mountains, which creates a rain shadow. This rain shadow is critical as Oregon does not have this. It reminds me a little of Alsace and how mountain ranges there affect growing conditions and therefore grape varieties.

Anyway, this leads to hotter, dry summers and cold winters, with significantly more sunshine and lower rainfall than Oregon. Irrigation from rivers like the Columbia is essential to viticulture here.

Washington is more suitable for warm-climate varieties like Cabernet Sauvignon, Merlot, and Syrah. However, cooler areas like the Yakima Valley still produce high-quality Chardonnay and Riesling.

Soils

Oregon:

Predominantly volcanic, sedimentary, and loess soils, especially in the Willamette Valley.

Jory (volcanic), Willakenzie (sedimentary), and Laurelwood (loess) soils impart distinctive flavours to Oregon’s Pinot Noir and Chardonnay and give them their complexity.

Washington:

More diverse soils, influenced by the ancient floods from Glacial Lake Missoula. These soils include basalt, loess, and gravelly sand, with deep, well-drained soils well-suited for irrigation.

The dry climate and these well-drained soils give Washington wines a more structured and concentrated character, particularly in red wines. At my level, I would describe these as deeper, but more experienced tasters may be able to pick out darker fruits versus Oregon.

AVAs

Oregon:

Known for the Willamette Valley AVA, which is famous for cool-climate Pinot Noir and Chardonnay. Other important AVAs include the Rogue Valley, Umpqua Valley, and Eola-Amity Hills.

Washington:

Dominated by the Columbia Valley AVA, which includes several sub-AVAs like Walla Walla, Yakima Valley, and Red Mountain. These areas produce a broader range of varieties, with an emphasis on Cabernet Sauvignon, Syrah, and Merlot, along with Riesling and Chardonnay in cooler regions.

Key Varietals

Oregon: Pinot Noir, Chardonnay, Pinot Gris, Riesling

Washington: Cabernet Sauvignon, Merlot, Syrah, Chardonnay, Riesling