The mysterious story behind Schramsberg’s quirky Napa dessert wine

The Schramsberg Vineyards Cremant Demi-Sec, a sweet sparkling wine made from the esoteric Flora grape.

Schramsberg Vineyards makes some of my favorite sparkling wines in California, mostly from Pinot Noir and Chardonnay — the standard Champagne grapes. But every time I’ve visited the Calistoga winery, I’ve been struck by a curious detail on its vineyard maps, noting the winery's use of a third grape variety that I’d never heard of: Flora.

After years of making mental notes to figure out what the heck Flora actually is and why Schramsberg is making sparkling wine from it, I finally got to the bottom of it.

Flora was one of many brand-new grape varieties bred at UC Davis in the mid-20th century by one of its legendary viticultural professors, Harold Olmo. To create Flora, Olmo crossed two European grapes, Semillon (a white grape found mainly in Bordeaux) and Gewurztraminer (a white grape found mainly in Alsace). Like many other genetic crossings, Flora was intended to inherit desirable traits from each of its parents — in its case, the honey-like notes of Semillon and the intensely floral aromas of Gewurztraminer.

To Schramsberg founders Jack and Jamie Davies, those characteristics looked ideal for sparkling dessert wine. "They wanted to have a unique California expression," said their son Hugh Davies.

They found some Flora planted in Yountville, at the Yount Mill Vineyard, which today appears to be the only Flora grower in all of California. According to Kendall Hoxsey-Onysko, whose family has owned Yount Mill since 1903, Flora was planted there soon after Olmo released his new creation in 1958. The first winery to buy the fruit was Charles Krug. Then Hoxsey-Onysko's grandfather entered into a "handshake deal" with the Davies, who have remained the vineyard's biggest Flora client — they’ve used it for their dessert wine, Cremant Demi-Sec, since 1972.

"My grandfather called it ‘pinkies,’" said Hoxsey-Onysko, because of the grape's pinkish color. (Gewurztraminer grapes turn pink as they ripen on the vine.) "The longer you let it hang, the more Gewurztraminer flavor will be there." That grape is famous for smelling like perfume and tasting like lychee.

It's remarkable that in Yountville, prime Cabernet Sauvignon country, a grape this obscure has endured for more than a half-century. Hoxsey-Onysko's family could undoubtedly improve their profit per acre by ripping out the Flora and planting expensive reds. But, improbably, there is a quiet demand for the grape. Schramsberg isn't the only winery buying the fruit: Matthiasson Wines buys some of the Yount Mill Flora to make vermouth, while ZD Wines blends some into a rosé, according to Hoxsey-Onysko. She also makes it into a straightforward white wine for her own label, Elizabeth Rose.

Taste the Schramsberg Cremant Demi-Sec, and you’ll get a sense of what Flora can do. Aromatically, it's not quite as over-the-top as Gewurztraminer, but traces of that grape's typical lychee and honeysuckle notes are present. It summons thoughts of baking spices — allspice, cinnamon — and citrusy desserts, like lemon souffle and creamsicle. The Schramsberg Cremant is fruity, bold and far less restrained than what you might expect from sparkling made from Pinot Noir or Chardonnay. I opened a bottle of the 2013 Cremant Demi-Sec recently and loved the toasted-brioche flavor it had developed.

This wine makes up just 2% of Schramsberg's total production, said Hugh Davies, a reflection of how unpopular dessert wines have become. Nevertheless, the Cremant Demi-Sec does have a small, devoted following among some longtime wine club members. Apart from its heightened level of sweetness, it is made differently from other Schramsberg bubblies: The base wine undergoes full malolactic fermentation, which turns a tart, brisk wine into a creamier one, and it has a softer bead — about a third less effervescence than wines like Schramsberg's Blanc de Blancs.

"It's ageworthy too," said Davies. "I have no issue breaking out 30-year-old bottles of Cremant Demi-Sec. The fruit will be a little more caramelized. There's a certain nuttiness and richness that develops over the course of time."

Schramsberg remains so committed to this wine, and by extension to the Flora grape, that it's preparing to plant two additional acres of Flora at one of its own vineyards in Carneros to supplement the Flora it buys from Yount Mill.

Sparkling dessert wines, and any wine made from the Flora grape, may never become Napa Valley blockbusters. But I’m glad they exist.

"Plenty of other wineries make Chardonnay and Pinot Noir-based sparkling wines," said Davies. "This is something that we do that nobody else does."