Beach plums: A secretive, seasonal treasure hunt on Long Island

Laura O’Brien’s annual preparation of beach plum preserves involves a collection so secretive that she uses East End foragers who pick the wild fruit in places their grandparents revealed to them decades ago.

Not even O’Brien, who owns the food company Josephine’s Feast and sells the preserves through her website, is sure where her forager — whose name she won’t reveal — finds the beach plum shrubs throughout Sag Harbor, East Hampton and Amagansett. He won’t tell her.

"I have a third-generation forager, a gentleman who has been foraging in the wild with his grandmother. He said if he told me where the beach plums were, he’d have to kill me," she jokes.

Beach plums only grow wild on bushes in areas near saltwater such as Long Island’s East End, Cape Cod and a few other areas in the Northeast. They ripen to purple in August and can be made into jams, jellies, preserves, sorbets, pies and syrups that are primarily sold in September, O’Brien says. "It’s a seasonal thing. People will start to pick them at the end of August. You have to get to them before the birds get to them, but when they are ripe. It’s tricky," she says.

A couple of East End farms sell beach plum jams and jelly, but when contacted, they did not even want to share that information. "We barely have enough to meet the demand that is there already," said one farm stand owner. Members of the Ladies’ Village Improvement Society of East Hampton once made and sold the jelly locally as a fundraiser. "We haven’t done it for quite some time. Not since COVID," says Rachel Cooper, director of operations for the society.

LOCAL ROOTS

The fruit gave rise to Montauk names such as Beach Plum Road and Beach Plum Resort. The beach plum is also said to be the namesake of Plum Island in Long Island Sound, which is in the news because the federal government, which runs a laboratory there studying highly transmissible livestock diseases, wants Suffolk County to take over the island.

Beach plums are the size of a niçoise olive, have a pit in them and are rarely eaten raw. "They’re not as sweet as a regular plum. They’re not great to eat raw because they’re slightly bitter. Also, they’re small, and there’s not much fruit on them," says Aimee Lusty, a local history librarian at the Montauk Library. "My son and I were picking them yesterday," she says. "They grow kind of all over. You can find them in the dunelands." The bushes are knee to waist high, Lusty says. "They have beautiful white flowers that bloom in the spring," she says.

O’Brien describes their taste as a cross between a wild cherry and Italian plum. "They’re not sweet, they’re almost prunelike," she says, which is why O’Brien boils them down, scrapes their skin and makes preserves.

The fruit is hard to cultivate purposefully, so O’Brien and others often depend on collecting the beach plums where they can — O’Brien even has some bushes in her Southampton yard. One East End farm stand has a small plot of shrubs, she says. But the plums are fickle — growing profusely one year, offering none the next, which makes a return on any cultivation investment really small, O’Brien says. "This year is above average. It's not a gangbuster year, but it's a much better year than anybody expected," she says.

‘IT’S A CHALLENGE’

O’Brien says she started her company, Josephine’s Feast, as a hobby, making apple butter after her daughter, for whom the company is named, was born 23 years ago. As she learned about what she calls "the wonders of New England and Long Island," she branched out into jams. She now works out of a commercial kitchen in Williamsburg, Brooklyn.

"We get all of our beach plums from Long Island," she says, using three foragers in all. "I go through 400 to 800 pounds of beach plums a year." She says if she’s lucky, 120 pounds of beach plum will make 200 8-ounce jars. Jars cost $18 each and typically sell out, she says.

The preserve process takes three days, she says — one day to cook the beach plums, one to scrape them, and one day to make the jam. "It’s a challenge, that’s what makes it fun," she says. "Why do I like it? Because nobody else does it."