For now, sulfites are able to kill the yeast that might spoil this wine.

Wine sometimes tastes a bit funky because it was contaminated during fermentation with a yeast called Brettanomyces bruxellensis. This yeast can give wine a variety of interesting flavors like “…horse sweat, Band Aids, barnyard, and burnt plastic…”

Winemakers usually keep this from happening by killing off the yeast with those dreaded sulfites. But for awhile now, people in the know have been worrying about the emergence of a sulfite-resistant form of this yeast. And this is a well-founded fear.

Yeast, like bacteria, are fast growing microorganisms with lots of variation in their DNA. If you hit a population like this with something that kills them (like sulfites for B. bruxellensis or antibiotics for bacteria), some small percentage are probably going to be resistant. These resistant strains can then grow and replace the sensitive ones. The end result is sulfite-resistant yeast ruining our wines.

To try to head off this problem, a group of scientists in Australia has figured out this yeast’s DNA. The hope is that scientists will be able to use this data to determine how B. bruxellensis might evolve into a more resistant form.

Note that despite much trumpeting online, they haven’t really solved any problems with this knowledge yet. They have merely created the tool that might let them solve a potential future problem. And given how cheap and easy DNA sequencing is these days, it isn’t necessarily even an impressive feat of technological prowess.

Still, it may one day prove useful in allowing winemakers to more quickly defeat a sulfite-resistant strain. Which can only be a good thing for wine making.

I don’t want to end this before saying a nice word or two about B. bruxellensis. This yeast can spoil wines but it isn’t all bad.

For example, it gives Belgian beers their special taste. And some winemakers actively seek it to give their wine a bit of a “brett” taste.

Still, a sulfite-resistant form would definitely be a bad thing for most winemakers. So scientists should definitely stay vigilant and be ready to come up with quick solutions using this new tool (and whatever other ones they can find) when sulfite-resistant B. bruxellensis begin to appear.

Right on the heels of California Wine Month and the beginning of grape harvest, comes Ken Burns latest documentary: Prohibition. The six hour series, which airs on PBS stations October 2nd, takes us back to an infamous thirteen year time period in our nation’s history when the commercial production and sale of alcohol was banned. For those not glued to the prohibition era TV series Boardwalk Empire, the 18th Amendment was passed in 1920 at the urging of the temperance movement.

Prohibition agents. Photo: Library of Congress

California’s wine industry, which had recently rebounded from a major pest infestation and was poised for great things, was devastated by Prohibition. Vineyards were ripped up and a majority of the more than six hundred wineries were shuttered. The few that remained open did so by producing wine for religious purposes. Beaulieu Vineyard was one of them. Founder Georges de Latour was a Catholic and a friend of the archbishop of San Francisco. Latour cut a deal to sell wine to all the priests in the diocese.

Prohibition was supposed to curb alcohol consumption, but instead the party went underground, giving rise to a thriving criminal economy run by bootleggers and gangsters. Port cities, like San Francisco, managed to stay pretty wet during those dry years, thanks to illegal liquor brought ashore in the dead of night, carried on ships from Canada. The roaring twenties saw the rise of a new breed of young women, known as "flappers," while beer, wine and spirits—some bootlegged, some made in basement stills flowed in hundreds of backroom speakeasies.

Flappers in the prohibition era. Photo: ©Scherl / Sueddeutsche Zeitung Photo / The Image Works

After years of lawlessness, the 18th Amendment was eventually repealed. You can still visit remnants of the prohibition era throughout the Bay Area. Some former San Francisco speakeasies still remain and dozens of wineries survived Prohibition.

Called “Ghost Wineries” some have become homes, others used as barns or shopping complexes in Yountville and St. Helena. A handful of wineries have been restored and now have a second life including Freemark Abbey, Far Niente, Hall Wines and Storybook Mountain Vineyards in Calistoga.

Freemark Abbey 1898. Photo courtesy of Freemark Abbey

We’ve come along way since the dry days of Prohibition, in just seventy five years the state’s award winning wine industry has built itself up to be a world leader with more than 3,300 bonded wineries. But a new threat looms — this one from mother nature. Research shows that California's prime wine producing areas could shrink dramatically over the next three decades from climate change.

Find out much more about the past and future of California wines at California Academy of Sciences Prohibition NightLife this Thursday evening. You can purchase tickets online for the event or buy them at the door. QUEST will be screening the segment on wine and climate change featured below and serving up wines for warmer temps. Also, Cal Academy will be leading mixology classes and screening a sneak peak of Ken Burns and Lynn Novick’s new documentary on Prohibition. Can you think of a better way to commemorate the end of the 18th Amendment than with a cocktail party and wine tasting?

This post was originally published on KQED's Bay Area Bites.

"Napa Wineries Face Global Warming"

California Academy of Sciences
Address: Map
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Twitter: @calacademy
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This post was originally published on KQED's Bay Area Bites.

 Jim Wolpert’s Alternative Varietals - References ( pdf ) Jim Wolpert’s Alternative Varietals - References

While looking for the answers, I found agronomist Bob Shaffer. Shaffer started out as a farmer, but soon realized that he was more interested in the soil than in what grew out of it. That led to a career in making and applying compost. He now works with Recology, the company that composts San Francisco's green waste, at their composting facility in Vacaville and with farmers who want to improve their crops.

One of Shaffer’s clients is Old Hill Ranch in Glen Ellen. As the name suggests, the vineyard is one of the earliest in Sonoma County and has many 100-year-old vines.

When Old Hill was first established, it was planted in the traditional way – a lot of different grape varietals were planted, producing a blended wine. The vineyard has a colorful map that identifies the patchwork of varietals on the property.

The vines are dry farmed, with no irrigation system running between the vine rows. This makes adding compost really important, as it helps with water retention in the soil. Old Hill’s owner, Will Bucklin, is also experimenting with compost tea, in which a small amount of compost is “brewed” into a dark tea to develop beneficial microbes. The tea can be added to a water supply or sprayed onto the leaves directly. It’s another way of making nutrients and protective microbes available to the plant.

Tiny young grapes on a vine at Old Hill Ranch, in Glen Ellen. Photo: Kate Szrom.

When QUEST visited Old Hill Ranch, it was a hot, sunny June day. There had just been a full moon and the blooms on the vines had set into tiny green grapes.

As he does in the summer season, Shaffer checked to see if the vines were getting water and nutrients by observing the leaves and tendrils on the vines. He pointed out some of the cover crops he has planted to prevent soil erosion. Through their roots, cover crops like grasses and legumes can also carry carbon deeper into the soil than compost alone would.

In the fall, compost will be applied at Old Hill and on other vineyards like it. Over the winter, rains will help spread the nutrients and beneficial microbes in the compost through the ground to be made available for next year’s growing season.

Climate change could dramatically affect the microclimates that have made California wine country so successful.

You've probably heard of the wines that made Napa and Sonoma famous, like Cabernet Sauvignon or Chardonnay. But what about Negroamaro or Nero d'Avola?

They're wine grapes that are well-adapted to hotter climates – the kind of conditions that California may be facing as the climate continues to warm. But for wineries that have staked their reputations on certain wines, adapting to climate change could be a tough sell.

Talk to any wine lover in California and they'll tell you how lucky they are to live in such rich wine-producing region. Take the recent meeting of the San Francisco Wine Lovers Group at Toast wine bar in Oakland, where the favorites are California Pinot Noir, Russian River Zinfandel, and Napa Cabernet.

In fact, the type of grape – or varietal – is how most of us think about wine.

"That's the big problem," says Andy Walker, a grape breeder in Viticulture and Enology at the University of California-Davis. "We've spent the last 100 years emphasizing varieties and we've really marketed those names very effectively."

Walker is strolling through UC Davis's test vineyard, where hundreds of different wine grapes from around the world are grown. The vast majority are unknown to consumers, because most wineries focus on only a handful of grapes. "Chardonnay, cabernet, merlot, pinot noir – those would make up probably a large percentage," he says.

Those are all French varieties, mostly suited for cool climates. California is warm by comparison and thanks to climate change, it's expected to get a lot warmer. Extreme heat can be the enemy of good wine. "It destroys acidity primarily and it changes color and aromatics," says Walker.

According to a recent study from Stanford University, about two degrees of warming could reduce California's premium wine-growing land by 30 to 50 percent. That could happen as soon as 2040. Water supply is also expected to be an issue.

"I think the interesting thing for me as a breeder is to take advantage of this and say, OK, here's a chance now to change thought and let's actually readapt varieties to California," he says.

Andy Walker walks through UC Davis's test vineyard.

But in many circles, grape breeding is a dirty term, according to Walker.

"Viticulture is the most backward form of horticulture that exists. We use these varieties that haven't been changed for decades, for millennia in some cases. And it really doesn't make any sense."

The problem starts in today's vineyards. If you look at rows of Pinot Noir vines, you aren't just looking at the original varietal. You're looking at clones. That's because vines are grown from a branch that's taken off an existing plant.

"Pinot noir is being propagated year after year after year. This essentially means that grapes have not been having sex very much," says Sean Myles , a geneticist at the Nova Scotia Agricultural College.

He says breeding is key for other crops, since farmers need seeds to plant every year. Wine grapes miss this opportunity to develop adaptability and disease resistance, since vines don't grow from seeds

"That means that we're not allowing the genetic material to be shuffled anymore. That genetic material is now standing still in time. And while the pathogens are evolving, the pinot noir is not," says Myles.

Andy Walker says there's plenty of genetic diversity out there for breeding, if you wanted to make today's varieties more heat tolerant or drought resistant. But there's a very big problem. Once your breed your pinot noir with something else, you can't call it pinot noir anymore.

"The last decision that hardest. Can we market this variety? We know it produces exceptional wine. We know the quality is better. But the next step is can we actually market it," says Walker.

That's a deal breaker for many vineyards, who think consumers won't buy varieties they don't recognize. Walker says looking ahead to climate change, there are already varieties out there today from Italy and Spain that would do well in a warmer California. "We could produce Barbera instead, or Negroamaro or Nero d'Avola from southern Italy and we'd be far better ahead."

These lush reds are popular in Italy but not so well known to Californians. Walker says it'll come down to marketing. "I don't think it's the consumer that's gonna make the shift. They have to be directed."

"I think it's really a pull from consumers," says Nick Dokoozlian, a Vice President at E & J Gallo Winery, the largest family-owned winery in the US. "In most cases, we're responding to consumer demand for a cultivar."

Dokoozlian says Gallo has been testing new wine varieties throughout its vineyards and has found some promising grapes. "The problem is we can't necessarily sell those varieties. Consumers aren't aware of them. The marketing aspect of climate change and the adaptation to climate change, really, the hurdles on the marketing side are much, much more significant."

Since vineyards can last up to 30 years, he says switching varieties is a major financial gamble. "The wine business is an extremely capital intensive business. The financial risk of planting the wrong variety in the wrong place is pretty significant."

Still, given the temperature and water supply changes projected for California, Dokoozlian sees the market shifting eventually. "I'm looking forward to having world-class California Nero d'Avola soon."

I just got back from a month-long rock climbing trip near Barcelona, Spain—and though I’d never been there before, the vegetation looked a bit familiar. Hiking around, my skin was constantly scratched by the stiff, sharp leaves of shrubby plants—similar to California’s chaparral. Lizards I almost recognized darted across dry patches of dirt. The weather was similar to California’s, too—being summer, it was hot and dry. This was no coincidence. Spain, in the Mediterranean Basin, is California’s climate cousin.

On every continent except Antarctica, the west coasts share a similar climate, called the Mediterranean climate. It is characterized by warm to hot summers with basically no rainfall, and winters that are short, mild, and wet. A world map of Mediterranean climate regions shows that in addition to the Mediterranean Basin and the coast of California, the west coast of South America from Peru to Chile, the northwest part of Africa, parts of western and southern Australia, and parts of South Africa all share the Mediterranean climate. The sweet spot is at about 35 degrees latitude, both north and south.

Climate is a product of ocean currents and the up-and-down movement of air above Earth’s surface. In the northern hemisphere ocean currents swirl clockwise, and in the southern hemisphere ocean currents swirl counter-clockwise, thanks to Earth’s rotation and the resultant Coriolis Effect. The direction of the currents means that water flowing along the west coast of all continents is cold, having recently come from the poles. Air follows the ocean currents, binging storms and precipitation in winter. In summer, the effect of the up-and-down movement of air in the atmosphere kicks in and influences climate. In summer, dry air sinks along the latitude band of about 30 degrees to 35 degrees. The dry sinking air prevents storms from moving in, and is largely responsible for Mediterranean regions’ summer droughts. Sinking and rising of air on Earth’s surface is due to the Sun’s uneven heating of Earth.

Those scratchy shrubs that plagued me throughout my vacation are the signature flora of Mediterranean climates. Drought-tolerant evergreen shrubs exist in every Mediterranean region. In fact, the word to describe California’s scrappy shrubs, chaparral, has Spanish origins—chaparro (initially txapar in Basque) means dwarf evergreen oak. We now use the word chaparral to refer to the whole habitat type, not just the shrubs themselves. Elsewhere, this habitat type goes by other names. In the Mediterranean region, it is called maquis; in South Africa, it is the fynbos; and in Australia, it’s called kwongan.

These shrubs are not phased by the fact that Mediterranean summers are bone dry. They have evolved plenty of adaptations to drought: small, light-colored leaves that reflect sunlight, rather than absorb it; leaves that often point towards the sky, to minimize the amount of sunlight (and heat) they absorb; and the ability to hang on to those leaves from year to year, rather than waste energy making a new set each spring. But by autumn, the crispy vegetation is pretty flammable. Spain appears to be prepared; it seemed like half the rock climbers I met were bomberos, or firefighters. However, climbers are probably drawn to this career not because they could potentially save their favorite climbing areas from fiery infernos, but because the hours (24 hours of work, 72 hours of weekend, repeat) facilitate frequent climbing trips.

The similarity of climates at about 35 degrees latitude is not lost to the wine industry. A map of wine producing regions of the world matches up almost exactly with a map of the Mediterranean climate regions. Growers can take advantage of the perfect conditions for growing grapes. And vacationers can take advantage of these conditions, too—I returned from my vacation relaxed, suntanned, and having tasted quite a few good wines.

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I often look at the chemical ingredients in what I buy. I shop at farmers markets for organic produce and use green cleaning supplies. So, it caught me off guard when a friend remarked, "you are so aware of what you eat, why aren't you just as curious about what you drink?" Well, we drink organic coffee but not organic wine. I was worried about sacrificing taste and I just didn't think most vineyards were heavily sprayed with pesticides. Then I learned that wine grapes are the second most sprayed crop in the state. This didn't seem like it could be that good for the farm workers, the Earth, or the consumer. Several studies have found trace amounts of pesticides in wine. They may be at extremely low amounts, but what kind of impact could pesticide residues have overtime?

Armed with a new green cause, I set out to find more information about eco-wines. I learned that organic wine is just one type of green wine — there is also wine made with organic grapes. It turns out I had been drinking some of these wines and enjoying them. The thing is, you can't call it "organic wine" if the wine has added sulfites, a naturally occurring compound. Most winemakers add sulfites to help preserve the wine and make it more stable. If a wine is made from organic grapes but contains sulfites, the world "organic" can only be mentioned as part of the ingredient claim on the back of the bottle. No wonder I didn't know I was drinking wine farmed organically.

It turns out northern Sonoma County and Mendocino county are hotbeds for green wine. In the course of reporting this story, I visited several of these wine makers. Bonterra Vineyards, below Ukiah, has been farming organically since 1987 and now farms one of their ranches, McNab, biodynamically. Their red blend is nicely balanced and tastes very good.

Biodynamic is a novel form of organic farming practice with its roots in France. A biodynamic vineyard is a self-sustaining ecosystem — making organic compost, removing chemicals from the soil and farming with the cycles of the Earth.  Biodynamic has its own international certification. (Here is a list of their certified wines). Just up the 101 from Bonterra is Parducci Wine Cellars. This family run company is farming organic grapes and in some cases, biodynamically. Parducci also claims to be one of the most sustainable wineries in the country.

Sustainable is a squishy term. Sustainable wineries may be running off solar power or doing creek restoration to save spawning salmon but they are not necessarily organic and they are not certified. However, the California Sustainable Winegrowing Program is working toward an industry certification. The idea is to raise the entire industry's practices and help vintners make more eco-friendly choices that often include using less chemicals in the vineyards.

Back to sulfites. This ended up being the main reason for the stigma still associated with green wine. Twenty years ago, green wines were uneven and there were not that many choices. Now, several of these eco-wines are winning high points from the industry. Organic wine can only contain naturally occurring sulfites, under 10ppm. Wines farmed organically must keep the added sulfites below 100ppm. Conventional wine can contain sulfites as high as 300ppm. When I was reporting this story, several folks asked me if I was going to explain why they get headaches from red wine. Isn't it the sulfites? Actually, it is not known why some people get headaches from drinking red wine. It could be the histamines. It doesn't look like it's the sulfites. Less than 1% of the population, according to the FDA, is sensitive to sulfites. The reaction is a respiratory one.

Anyway, if you enjoy wine, I encourage you to think beyond red and white but to consider green, too. To find out more, listen to our radio story and check out our links. Also, green wine pioneer, Paul Dolan together with Parducci has created a green wine handbook which is very helpful.

Listen to the The Politics of Green Wine radio report online.

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In our radio story, we feature the stylishly high tech Vineyard 29 and the Robert Mondavi Winery, but scores of other wineries are using a similar toolbox of technology to help them monitor the soil's water content to grow better grapes. The technology ends up conserving water, too. Remote sensing, ground penetrating radar and satellite technology have helped Mondavi cut back on water use by 30% in recent years.

Winemakers are using some of the same technology that NASA uses to study Mars and engineers use to build hi-rises and freeways. A typical toolbox includes multi-spectral imaging, weather stations, neutron moisture probes, and pressure bombs and there is a plethora of newer technologies in the pipeline. But enough with all the high tech gizmos. How does wine from high tech vines taste? The answer might be found in the success of the winery. Mondavi has won numerous awards over the years and there is a two-year waiting list just to purchase Vineyard 29 wines.

Check out our slide show to see some of these technologies or listen to our radio report on high tech in the vineyards.

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Quest Educational Resources

 Print Guide - Bothe-Napa Valley State Park

 Bothe-Napa Valley State Park KML file

 Tips to get the kids in your life out into nature

 Designing an Exploration on Google Maps

Additional Links

• Soil Survey of Napa County, California
• The Sparkling Science of Champagne
• Check Please! Bay Area – KQED