This article is a preparation for WSET Diploma Unit 5. It’s about sparkling wines from United States of America, including those from California, Oregon and Washington.

Location, climate & soils

The majority of the sparkling wine made in the USA comes from California, accounting for approximately 90% of American sparklers.

The best sites for premium sparkling wine in California are located in Napa Valley and Sonoma County.

• Los Carneros AVA is ideal for sparkling wine, because it benefits from cooling influences from the San Pablo Bay. Domaine Chandon, Mumm Napa and Taittinger’s Domaine Carneros are situated here.
• In Sonoma, there’s also Russian River Valley AVA, which tends to be a bit cooler due to the more open exposure to the Pacific Ocean. The sub-AVA Green Valley is the coolest and foggiest portion of the Russian River Valley.
• The western parts of Mendocino County AVA are relatively cool due to its proximity to the Pacific Ocean and its northernly location. The sub-AVA Anderson Valley benefits the most from these advantages. Roederer Estate is located here.

In Oregon, most of the vineyards for sparkling wine are located in Willamette Valley AVA. It has a moderate maritime climate, dry and sunny summers with the occasional breezes from the Pacific and a large diurnal temperature range.

In Washington, the growing of grapes for sparkling wine is concentrated in Columbia Valley – east of the Cascade Mountains which function as a rain barrier. It’s dry and sunny throughout the summer with a large diurnal shift.

Grape varieties

There are no limitations, but these are the grape varieties which are predominantly used.

• California: chardonnay and pinot noir
• Oregon: chardonnay and pinot noir – but also muscat, pinot gris, riesling and muller thurgau
• Washington: chardonnay – with some riesling and pinot noir

Vinification

The best sparklers are made following the traditional method. There are no minimum ageing requirements, but most producers will age their wines for 12 months minimum.

Styles and production

Brut is the most popular, but all styles are made.

• If a vintage is stated on the label, 95% of the grapes should come from that year.
• If an AVA is stated on the label, 85% of the grapes must come from that AVA. (Oregon is the exception to the rule and demands 95% of the grapes to come from the AVA stated on the label).

You like? Check out other WSET Diploma study notes.

Sources & suggested reading:

Tom Stevenson & Essi Avalan – The World Encyclopedia of Champagne & Sparkling Wines
Oregon Wine Press – Two sides on every label

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