Cultivating the Cape's famous oysters

WELLFLEET -- The more you talk to oyster connoisseurs, the more you hear the language of wine experts. They refer to an oyster's "finish" and describe the taste as "crisp" and "clean," or perhaps as "fruity" or with "vegetable overtones."

Nowhere is the taste and texture of the oyster examined more closely than on Cape Cod, described as the Napa Valley of shellfish by fisheries and aquaculture specialist Bill Walton. Oysters grown in cold, clear water -- as on the Cape or in Canada -- have a sweetness to them, says Walton, who works at the Cape Cod Cooperative Extension. Even within the Cape, conditions, and therefore flavor, vary from bay to bay and grower to grower.

The analogy to wine is apt. The environment in which oysters grow has everything to do with how they taste, much as the characteristics of wine are largely determined by soil and climate for growing grapes. Oysters are affected by water temperature (the lower the temperature, the firmer the meat), salinity (higher salinity creates a cleaner, sharper flavor), and the vegetation on which they feed. And they can have a different taste and texture at different times of year.

"Nationally, Cape oysters are distinguished by how clean-tasting they are," says Walton, who also works at the Woods Hole Oceanographic Institution Sea Grant. Restaurants recognize the similarities to wine, too. To Gwen Butler, manager at B&G Oysters in Boston, and Brian Flagg, executive chef at Jasper White's Summer Shack, West Coast oysters are "fruity," with vegetable overtones, but they love the characteristics of East Coast varieties. Wellfleet, on the Outer Cape, is the flagship of New England's oyster industry, with a seafaring tradition that dates back to the early 1600s. But in the last decade, several other parts of the Cape -- Brewster, Barnstable, Chatham, and Dennis -- as well as Duxbury and Martha's Vineyard have also become known for oysters.

Bob Wallace, of Billingsgate Shellfish, has been growing oysters in Wellfleet since 1982. Wallace, who says growing oysters is a "labor of love" despite the hard work, has two contiguous 2 1/2-acre grants in South Wellfleet, where the water is relatively shallow -- 10 feet deep at high tide. At this depth, oysters grow a thin shell with a lot of meat. Those grown in deeper, colder water have a thicker shell.

Wallace is proud of his oysters' deep cup, which means there is a lot of meat inside. "Once you've had an oyster when they're really meaty and full, you get spoiled," he says.

Like most commercial growers, Wallace begins with oyster seed, called spat, which he gets from a hatchery in Maine, though he has collected some naturally. When the seeds arrive, in tightly woven mesh bags, each is roughly the size of a pepper flake. It takes two to three years, with continuous care, for them to grow to market size, three inches or more.

Cultivating the oysters means daily visits to the flats, where they grow in mesh bags strung along poles. It is important that the oysters have plenty of room, so as they get bigger, growers transfer oysters of the same size to new bags, with larger openings. In the process, they sort through the oysters, separating those that have fused together and removing mussels and other animals that may have attached to their shells.

In mild, dry weather, life on the flats can be very peaceful. But when the wind whips up and the temperature drops, the labor of love is mostly labor. Though some oysters can survive a winter at the bottom of the sea, protected by sand, many growers take their oysters out of the water to protect them from ice that forms on the surface. They store them in pits, or temperature- and humidity-controlled chambers, between 32 and 40 degrees Fahrenheit. During this period, oysters stop growing and build up glycogen, a carbohydrate that sustains them through the cold weather and gives them their sweet taste.

Some in the business say this is one reason for the claim that oysters are best eaten in months containing an `r.' Another is the fact that oysters reproduce in the warmer months, which changes their physiology and, in turn, their flavor. "During the spring, the oysters are building their sperm and eggs." says Wallace. "The change in temperature triggers them to let go," meaning that they release their sperm or eggs. Then they have to eat for at least a month to regain their meat, he adds. Deep-water oysters let go at 72 degrees, he says, but in the shallow flats of Wellfleet, the water is warmer, so the oysters spawn early.

An exception is Duxbury oysters, which never spawn. "We get the southwest wind, which blows the warmer surface water to Wellfleet," explains Skip Bennett, a premier grower in this South Shore town. Bennett is part of a cooperative that grows and distributes Duxbury oysters under the Island Creek brand name. In July, Duxbury water can hit 70 degrees, but as soon as the southwest winds come, the temperature drops to around 54.

Duxbury oysters are "very plump and briny with a sweet, buttery finish," says Bennett, who has been farming the bivalves for roughly 10 years. "The plankton prevalent in Duxbury gives oysters their taste," he adds. Duxbury oysters are favorites at many Boston-area restaurants, including East Coast Grill, where they are the house oyster; B&G Oysters and No. 9 Park; and the Summer Shack.

"We buy and sell a lot of oysters, and focus on cold-water oysters -- nothing farther south than Connecticut," says Flagg, of the Summer Shack. "We use as many local products as we can because it helps the local economy and it means the food is fresher and generally tastes better."

Summer Shack features 12 to 13 different oysters at its raw bar at any given time. Most are from the East Coast, but the restaurant sometimes offers premier oysters from the Pacific Northwest. "They're great," Flagg says, "but we know [the growers] here better." Flagg says when he's shaking a grower's hand, " I know he's the guy who just took the oysters out of the water. It's nice to put the face with the bag of oysters."

The selection at B&G Oysters is slightly more expansive. The restaurant offers about 16 different oysters daily, and varieties are changed often.

There's never a bad time to eat oysters, but the prime season is just beginning. So enjoy the full variety of what our local waters
offer. And wash them down with
a glass of crisp, clean white
wine.