For a diminutive mollusk, the slipper snail sure has managed to rack up a lot of names.* Among scientists, the creature goes by Crepidula fornicata and has a reputation for invading the phytoplankton feeding grounds of other shellfish and, as its Latin name implies, a particular dedication to reproduction.* New Englanders—and particularly Rhode Islanders—know the animal best by its nickname, decker, after the way it grows in stacks (or decks) so thick, hard, and deep that they can impede the clamming process. Recently, Sean Barrett, owner of the sustainability-minded seafood purveyor Dock to Dish, has tried to rebrand the animal as “wild Montauk escargot.” This is because, if he and others in the seafood industry have their way, slipper snails will trade in their competing identities for a simpler appellation: dinner.
Slipper snails (or slipper limpet, in the United Kingdom) have been consumed by humans for many years—just not in the United States. In France, the species has yet another name, this one loving: le berlingot de mer, or “candy of the sea.” The term refers both to a popular, pyramidal French candy sold in Brittany, and to the flavor itself of the snail, which is sweet. Although the snail has had a strong presence on America’s East Coast for a long time—so much so that the Long Island–based Native American tribe the Shinnecock historically used the shells as wampum—it has never been broadly regarded here as a food source.
In fact, slipper snails were for many years harvested in tandem with other Long Island shellfish and then promptly discarded, a bayman’s nightmare. The hermaphroditic animal can produce thousands of offspring in a year, and the mere act of clamming can actually help it spread. “They’re so abundant, and you’re talking to traditional clam diggers who go out with rakes,” Barrett told me. “They’ll tell you stories about how they have to break their backs and dig down a few layers of these to where the clams are.”
But as sustainability grows as a priority in a world where traditional food systems feel unsteady, there is renewed passion for investing time in unlikely and overlooked food sources. And there’s no better example than the slipper snail. “I can’t remember the last time I’ve had this much ooh, ahh, wow excitement over a seafood item,” Barrett said. He has placed the slipper snail in some of the finest restaurants in New York. Tech giant Google has recently added the snail to the famously well-curated menu of its employee cafeterias. At Dan Barber’s Blue Hill, the snails are served in a traditional escargot style, bathed in butter and garlic and baked until bubbling. Thomas Keller’s Per Se serves them in the shell beneath a Parmesan custard that is then topped with toasted garlic and parsley oil.
The slipper snail’s path to such esteemed tables has been a peculiar one. Originally native to the Northeastern coast of the United States, it hitched a ride east during World War II, on the hulls of ships, eventually landing in Europe. “They set up colonies of slipper snails that just flourished and bloomed,” Barrett explained. “This really spooked out the French and the Brits.” The only effective way to cull the population whose presence was damaging the other shellfish was, naturally, to begin eating them.
“The old saying has always been: How do you control a nuisance? You control a nuisance by making it edible, and humans control the rest,” said W. Brett McKenzie, professor at Roger Williams University. McKenzie has authored the sole stateside report of slipper snail market potential in the United States. Among his conclusions is this: Slipper snail meat and its taste is not the problem regarding its lack of popularity; reaching the meat, however, is. The shell’s chamber and stubborn exterior—made from calcium carbonate, a formidable adversary to shucking—make the meat resistant to harvest.
Some years ago, Pierrick Clément, owner of France’s Britexa, a company that both harvests and processes the slipper snail’s meat, developed a solution, but it remains proprietary. “He figured out how to process the shellfish—and that is one of the big roadblocks,” McKenzie said. “How do we process it? Pierrick packages them. What Pierrick did was the same thing that we need to do here. Pierrick found a method to process and package it for the market. Harvest, process, and package.”
Luxury restaurants aside, the goal of making the slipper snail accessible for the average consumer hinges on whether an American company can recreate Clément’s harvesting and processing magic. “[I]t comes in this bulky shell that is just a little off-putting, and it requires some scrubbing and cleaning,” said Sarah Schumann, acting science director of Eating With the Ecosystem, a group promoting sustainable seafood consumption. “The yield of the meat is low, compared to the bulk of the shell. I think that the secret to making it marketable is making a pre-shucked product like they have in France.” For now, in the United States, the only consumer-based access to the slipper snail—apart from finding it on the shorelines and digging right in—lies in restaurants, where small-scale processing is currently possible. The hope, Schumann says, is that technology catches up to what she sees as a burgeoning demand. If slipper snails cannot be broken down for home cooks in the United States, the way they have been in France, there may be no path to marketability.
The secret to promoting slipper snails, too, lies in culinary education: The anatomy of the slipper snail poses both a puzzle and an opportunity for cooks. Meat is divided into two distinct and different-tasting sections. “If you flip them upside-down, there’s a small little deck inside the shell, and then it’s got two anatomical hemispheres,” Barrett said. “One is a suction cup disc that’s kind of tough. There’s a traditional, true snail body that’s attached to that. … The suction cup is [a] dense, tougher, saltier morsel. And that backside of that is a sweet, soft, delicious little scallop-tasting snail.”
The combination is, to hear Barrett tell it, “a real party in your mouth.” But those differing textures and tastes also require thought, foresight, and some broad culinary understanding. The tough exterior may not, after all, benefit from gentle cooking or delicacy, just as the tender interior may not benefit from more aggressive methods or stronger flavors.
Still, Mr. Barrett believes that he has, in fact, stumbled on culinary gold. “There is a degree of mystery as to how this just laid dormant and never got recognized as a culinary delicacy until 2020,” he said. “Necessity is the mother of invention. When you get into the colder months is when you really have to sit with the fishermen and ask what is available. In the rest of the seasons of the year, you have such robust variety.”
A lack of seasonal variety (winter is notoriously nonabundant, as far as Northeastern fishing goes), paired with an overpopulation of slipper snails, could, Barrett says, fuel increased popularity. And the benefits extend far beyond the basic pleasure of encountering a new, delicious food. Barrett suggests that consumers look to the trophic scale—a directive diagram of the food chain, with major, low-reproduction predators at the top and more abundant sea-based foods, like kelp, at the bottom—when making decisions about what they should eat from the ocean. “What we’re looking to do essentially is put a light harvesting pressure on as broad of the ecosystem as possible,” he said. “People need to be eating lower on the trophic scale.”
Eating items toward the bottom of the scale—phytoplankton, seaweed, and, yes, slipper snails—can maintain balance in the environment. “Eating the ecosystem is all about balancing our diets with what the ecosystem is producing,” Schumann said. “This is a species that’s actually increasing. The anecdotal evidence coming from the species is that we’re experiencing a surge.” The goal is to ensure that no single species overtakes the others, since the stability of ocean life is, at best, fragile.
On the culinary side, chefs working with Barrett and Dock to Dish have taken this new-to-them ingredient and run with it, creating everything from slipper snail pasta to traditional escargot to Japanese dashi—a fish broth traditionally made from kombu and bonito flakes. With no real blueprint for an American approach to using the slipper snail, chefs see a rare tabula rasa, an incomparable opportunity to forge new ground in a field often hidebound by traditional expectations. For those invested in the intersection of innovation and dining, then, the slipper snail—or if you insist, wild Montauk escargot—pulses with possibility.
Correction, March 4, 2020: This article originally misidentified the slipper snail as a bivalve. It is a gastropod, a subset of mollusks. It also mischaracterized the feeding habits of the slipper snail. They eat phytoplankton, not other shellfish.
