WALNUT CREEK, California ― It’s no accident that oysters are identified by the specific tidal region in which they are grown. Think of the sweet Miyagi oyster lifted from Tomales Bay, that narrow, cool Pacific Ocean-fed inlet north of San Francisco.

Like that sense of place that defines a wine ― terroir ― the flavor of these beautiful bivalves is influenced by the nutrients, temperature and salinity of the water in which they are raised. In the industry, they call it merroir.

While oysters’ chewy texture and salty liquor may not be for everyone, those who down them can also delight in knowing that oysters have a low carbon footprint. They clean the water and draw their nutrients from the waves.

In many ways, they are stewards of the environment. So are the people who bring them to market.

“The people are each a pocket of experience, but when it comes to the bigger issues, they’re in it together,” says Gwendolyn Meyer, a photographer who fell in love with oysters while working as a chef in Big Sur. Her images in “Oyster Culture” (Cameron & Company, 2011) celebrate the oyster farms and culinary scene of West Marin, a bastion of oyster cultivation.

From the oyster farmer who harvests at dusk to the chef creating mouthwatering mignonettes, oyster people share a taste for sustainability, consumer education and culinary simplicity.

The oyster man: Scott Zahl was a marine biology student when he was bitten by the bivalve bug. Upon graduation in 1982, he took a job with the Tomales Bay Oyster Company in Marshall.

The following year, Zahl went into business for himself. He now leases 10 acres of water near Marconi Cove from the California Department of Fish and Game. He raises Miyagi oysters that he sources from hatcheries and nurseries.

“It’s a beautiful spot and I enjoy the work even though it’s pretty hard,” says Zahl, who lives in Marshall and sells his oysters to restaurants throughout San Francisco and Marin.

He baby-sits the bivalves for up to two years, growing them in a plastic mesh bag on a steel rack and harvesting them when they’re exposed, usually at low tide just before the sun sets.

“It’s like gardening. When the oysters get big and crowded in the bag you need to do a lot of thinning out of barnacles and sponge,” he says.

Several nights a week, Zahl trudges in sandy rubber boots to the Novato porch of Waterbar chef Parke Ulrich, where he deposits a cooler of 500 freshly-plucked oysters, bound for happy diners’ plates the next day.

The fishmonger: Not every restaurant works directly with a farmer. Many rely on fishmongers such as Mike Weinberg-Lynn of San Francisco’s Osprey Seafood to source their seafood.

“We’re the middleman between the ocean and the restaurant,” says Weinberg-Lynn, who has been a seafood wholesaler since 1977. He sources oysters from Tomales Bay to British Columbia for clients such as Postino in Lafayette, California, and Walnut Creek Yacht Club.

Twice a week at the crack of dawn, Weinberg-Lynn, who lives in Walnut Creek, Calif., sits down in his Pier 33 warehouse to taste through the supply.

Over a cup of black coffee ― its smokiness makes a winning pairing, he says ― he checks for various flavor profiles, from the rich, creamy flavor of Kumamotos to the crisp brininess of Malpeques.

Weinberg-Lynn says that factors such as diet and the salinity, temperature, and mineral content of the water all contribute to an oyster’s flavor and texture.

“It’s a rock with a piece of meat in it,” he says. “In that way it’s a very inexpensive delicacy.”

He credits the boom in oyster culture to Hog Island Oyster Company, which has two retail locations in the Bay Area, as well as the increasing interest in regionally specific food.

The chef: Chef Parke Ulrich of San Francisco’s Waterbar tasted his first oyster at the age of 5 on a summer fishing trip to New Jersey’s Ocean City.

“I liked it because it was cold and I could use my hands to eat it,” Ulrich recalls.

But he didn’t appreciate their toothy texture or merroir until he became a chef 20 years later.

“Oysters are like wine,” Ulrich says. “They are influenced by what they filter from the ocean. They clean the water and you don’t have to feed them anything. An oyster is the epitome of being sustainable.”

Waterbar has one of the largest oyster programs in Northern California. At any given time, there are 20 types of oysters on the menu.

Since they fetch $1 each until sundown, it’s no wonder the restaurant serves at least 1,500 a day.

To open an oyster, Ulrich lays it in a small towel on a table. He holds the shell cup-side down and inserts his shucking knife into the top, twisting until he breaks the hinge. Next, he slides his knife down until he finds the abductor muscle. He severs it and lifts the top shell, careful not to let any liquor escape.

“That’s the seawater, the flavor of where it comes from,” he says.

Ulrich bakes oysters with French butter or house-made sauerkraut. He serves barbecued oysters, a dish made famous in Marin. And he certainly knows his way around an oyster stew or Po Boy.

But, like most chefs, he is a purist. He prefers them raw with a drop of hot sauce.

“They’re just so delicate,” Ulrich says. “The more you don’t mess with them, the better.”

What goes well with oysters?

Salt is usually a wine killer. But there is something almost ethereal about the brine of a freshly shucked oyster and its ability to pair with a host of adult libations, including wine.

If you need proof, spend an hour with Kevin Weinberg and Ellen O’Connell McCarty of Walnut Creek Yacht Club. Their formidable seafood restaurant is a great place to get an education in all things bivalve.

I stopped by to slurp and sip with the pair on a recent afternoon and explore the extent to which texture, flavor, and that signature sea spray contribute to an oyster’s compatibility.

By the end of my visit, our corner table looked like it had been inhabited by the cast of “Deadliest Catch.” Or Anthony Bourdain.

Half-empty cans of Guinness sat next to uncorked bottles of Sancerre, sauvignon blanc and a lone single-malt scotch. Shells once filled with oyster meat were scattered about the table, empty and meaningless. I tried to make sense of the tasting and decide whose side I was on.

O’Connell McCarty, the wine director, stood by the classic notions of oyster pairings. Low-alcohol white wines with high acidity.

“I think low alcohol is crucial,” she said, pouring me a nonvintage Nicholas Feuillate Brut. “It cleanses your palate for the next bite.”

Agreed, I thought, as I considered the icy spread of a dozen oysters on the half shell, their jiggly, gray bodies glistening in briny baths.

I popped a small Malpeque, an East Coast oyster, into my mouth and took a swig of the Champagne. Oh yes, definitely. Bubbles are an extra step in scrubbing away the brine ― like the rough side of a kitchen sponge on your palate.

Next, she busted out a 2009 Andre-Michel Bregeon Muscadet Sevre et Maine from the Loire Valley. By French law, muscadet cannot top 12 percent alcohol. And because the wine has a flinty essence, it’s great to capture the sharp mineral flavors of European Flats, like Belons. Another great combination.

Executive chef Weinberg, who puts his staff through an oyster class complete with final exam, said oyster devotees should not get carried away with wine pairings. Matching species and their unique flavor profiles with different wines is “like splitting hairs,” he said.

But when you consider that one of the main factors in pairing food and wine is texture, or mouth-feel in wine-speak, splitting could be worth your time. Some oysters are big. They are also chewy and chunky. And if they lack brine because the water they grew in was low in salt content, you may feel like the bivalve is taking over your mouth. I personally feel like gagging when I have an oyster like that.

Enter the 2010 Domaine Daulny Sancerre. Sancerre benefits from having the steely acidity of sauvignon blanc but with a soft, almost milky texture.

“You’ve simply got more oyster in your mouth so the creaminess of the Sancerre complements that,” Weinberg said. He was right.

Another favorite was the 2009 Gurrutxaga Txakoli. Txakoli is a light, citrusy Basque wine that is bottled with a bit of carbon dioxide for a natural spritz. That fizz accentuates the freshness and acidity of the wine. I probably liked it because it reminded me of sparkling wine.

Tradition is powerful. But cultures have different ones. So, when Weinberg cracked open a can of Guinness and offered me a cold glass with one of two remaining oysters, I wasn’t about to insult the man. I slurped down a Belon with a gulp of Guinness. You know what? I dug it.

“Isn’t that good? That’s why we like smoked salmon and smoked trout,” O’Connell McCarty explained. “It’s that smoky, roasted-like element of Guinness that is natural with fishy flavors.”

It certainly explains why Irish folks take their raw oysters with a drop of scotch. I tried that too, under McCarty’s and Weinberg’s watchful eyes. McCarty asked me what I thought. “Too much heat for me,” I told her. “I’d rather stick to hot sauce.

By Jessica Yadegaran

(Contra Costa Times)