Nestled in the hills just north of San Francisco is one of the most famous wine-producing regions in the world. Visitors come from all over to sip wine at bucolic wineries overlooking thousands of acres of grapes. But how did this region become famous for wine? That’s what Bay Curious listener Michael Viray wanted to know. The temperate Mediterranean climate would be good for growing all types of crops. How did wine come to dominate here?

The First Wine

Catholic priests planted the first wine grapes in Sonoma County in the early 1820s at the Mission San Francisco Solano. And just a decade later, in the 1830s, when European settlers began making their homes in the Napa Valley, wine grapes would have been one of their crops. Commercial winemaking in what we now know as “wine country,” however, traces its roots back to a German immigrant named Charles Krug.

While living in San Francisco, Krug managed a German language newspaper and is said to have experimented with winemaking as a hobby. When Krug married Carolina Bale in 1860, her family offered land just north of St. Helena for her dowry, says Jim Lapsley, professor of viticulture and enology at UC Davis. The Charles Krug Winery opened there in 1861 and is considered to be the first commercial winery in Napa Valley.

The Gold Rush

The Gold Rush rapidly increased California’s population, and the state joined the union in 1850. In 1840, California had about 8,000 people. Just 10 years later, the population had grown to roughly 100,000. Meanwhile, San Francisco was booming. In July 1849, 5,000 people called it home. Six months later, the population was five times that. By 1870, the population of the city had reached 100,000 people.

In reaction to this population boom, more and more grape growers began to plant grapes in what we now know as wine country, an area that stretches through Napa, Sonoma, Mendocino, Lake and Solano counties. But California wines only represented a fraction of the wine consumed in the United States. California had no bottling plants, so grapes were shipped east on trains for bottling. And it was cheaper for consumers on the East Coast to import wine from Europe by boat.

In 1875, the federal government stepped in and increased import taxes on European wines. That made shipping wine from California more financially competitive, and California began to dominate the domestic table wine market. The more expensive wines still tended to come from Europe.

Booms and Busts

By the 1880s, a small bug related to an aphid arrived in the Napa Valley. Phylloxera ate the roots of European grape varieties like Vitis Vinifera. Jim Lapsley says that when phylloxera arrived in wine country, “It killed the vineyards. And the only way you could really come up with a solution was to plant on grafted vines. The bottom, the rootstock would be a native variety,” which the bugs didn’t like, “And then on the top we have a graft with the European vinifera.”

Grape growers also tried a few other solutions, including pumping poisonous gas into the soil and flooding entire vineyards. But the grafted rootstocks worked best, and they are still used widely on vineyards in Sonoma, Napa and surrounding counties today.

The 1920s brought another rough patch to California winemakers. The U.S. Congress passed the 18th Amendment — better known as Prohibition — in 1919. Prohibition outlawed the production and sale of alcoholic beverages. Many wineries went out of business, and Lapsley says those that survived took advantage of a loophole in the law that allowed people to produce wine at home.

“The grape industry in California switched from producing wine grapes to be sold to wineries, to grapes that could be shipped back east to home wine producers,” Lapsley said.

Despite Prohibition, by the end of 1921 Americans were drinking again at almost two-thirds the level they had before the law was passed. And eventually lawmakers gave in, overturning the 18th Amendment in 1933, and making alcohol of all types legal again in the United States.

The War Years Changed Everything

Before World War II, the wine produced in the North Bay still didn’t look much like what we see today.

“California wineries were producing bulk wine and shipping it out of state to bottlers,” Lapsley says. ”So most of the wine that was produced in California was not bottled under a California label.”

This would change as the government took over various parts of American industry for the war effort. The railroad cars that used to send wine east for bottling, were commandeered, leaving the wine industry with one solution — move their operation to California. So, Lapsley says, “In ‘43 bottlers start bottling in California for the first time.” And, those new bottles printed the locale on the label — making California wine a bottled and branded commodity.

The popularity of wine produced in the North Bay exploded in the 1970s thanks to the millions of baby boomers coming of age. They loved white wine. Around this time, new innovations were arriving at wineries around the region. Things like refrigeration and stainless steel tanks not only helped sterilize and streamline the winemaking process, but also made it taste better.

“When we ferment grapes, and especially white grapes, at lower temperatures, the fruity characteristics that are inherent in the grapes are enhanced and maintained,” Lapsley says.

Judgement of Paris Brings Respectability and Renown

The real turning point for the respectability of California wines came in 1975 at the so-called “Judgement of Paris.” California wines went head-to-head with European favorites and won a blind-taste test by French judges. The results sent a shockwave through the wine industry.

“It was a feature article [in] Time Magazine,” Lapsley says. “And basically it was a shot in the arm for the industry. It was validation. And we had even more people coming in and wanting to start wineries or plant vineyards.”

Today, wineries and grape growing operations work side by side in wine country. The industry has survived a lot in the past 160 years, but its challenges aren’t over. Climate change has led to hotter, drier weather and is forcing the industry to plan for and adapt to an uncertain future.

But don’t worry. People in the know say with absolute confidence that wine country — and its spirit of innovation — are here to stay. Cheers!