Beach plums are a rare and rather glorious fruit and if you have a beach plum tree, you really ought to learn how to make beach plum jelly. What else are you going to do with the rather bitter small plums? A beach plum plucked off the tree is far from tasty, but the jelly? There’s nothing more delicious and tart than a jar of this prized preserve.  Beach plums are cherry-sized, red, and purple plums that grow on craggy trees in sandy soil along the coast of New England.  We have quite a few of them at our house on Martha’s Vineyard. My favorite one is an old, wizened, bonsai-shaped tree that takes up most of our wee garden. Were it not for memories of the tangy beach plum jelly my father-in-law used to make, we would have jettisoned this particular tree long ago.

Beach plums are notoriously fickle.

Beach plums are notoriously fickle and ours did not fruit for ten years, despite constant pruning, careful organic fertilizing and battling an insidious caterpillar creature that took over whole branches with a net-like web. After years of treating our beach plum tree like a prized sovereign prince, it began to fruit. The first year, it sported just a few plums and then finally, two years later? We had a veritable bonanza of beach plums. Truth? We have no idea how long this beach plum windfall will last. Friends who own beach plum trees complain that their tree only fruits once every few years, with no regular pattern.

My husband and I both come from a long line of jammers. David’s father, Anthony Lewis, a Pulitzer Prize winning journalist for the New York Times and a long-time summer Vineyard resident, approached picking beach plums and making jelly with the fervor of a madman. He owned a large tan burlap bag that looked like an ancient woodsman’s rucksack which he hung on a hook to extract the juice. Every August, he’d send out the grandkids to various “secret” patches of beach plums on the island to collect the ripe berries. A stickler for what was indeed ripe, he tossed any berry with the least amount of green on its round body.  Once I sat at the kitchen table while he carefully stewed the berries and slowly began to pour the mushy mixture into his draconian jelly bag, only to realize he had forgotten to put a bowl underneath to catch the juice.  He screamed so loudly, I thought somebody had died. The screams were followed by a litany of foul words so horrible that surely no other Pulitzer Prize winner had uttered such filth. It wasn’t until I began making my own beach plum jelly that I truly understood the depth of his rage. A hearty hoard of beach plums might yield little more than 2 cups of the precious juice. Sadly, when he died, the draconian burlap bag was never recovered. Worse, we neglected to get him to write down his recipe.

If you google Beach Plum Jelly recipes, you’ll get a scattering of wildly divergent procedures and device. I tried and failed at making the precious jelly and finally reached out to Linda Alley, owner of New Lane Sundries on Martha’s Vineyard. She knew my father-in-law well and occasionally the two shared their favorite picking spots.  She recited the recipe to me.  Here it is:

• 10 heaping cups beach plums (which should yield 4 cups juice)
• Water to cover
• 6 & 1/2 cups sugar
• 2 package Certo® (or 3 ounces liquid pectin) * Disclaimer: Usually I avoid pectin and try to get my jams and jellies to firm up naturally. However, when it comes to this rarest of plums, Linda Alley advises you don’t take your chances on getting it to gel.

Pick over your beach plums, picking out any stems and throwing away any fruit that are blistered or too green. Ripe beach plums really are burgundy colored or deep purple. Put the beach plums in a large stock pot and add water until the beach plums are just covered.  Cook the plums over medium-high heat until they get soft and start to exhale juices.  As they soften, feel free to use a potato masher to squish the plums and extract more juice. Bring the mixture to a boil and cook over moderate heat for 10 minutes.  This process might take 35-40 minutes.

Once the plums are soft, pour the mixture into a cheesecloth bag, or a colander lined with cheesecloth and allow the liquid to slowly drip out. Be patient, because you’ll want to retain every precious drop of juice. (Linda strains her plums through an old pillowcase and lets it hang over night or at least a few hours).  Do not squish the bag or plod through the mushy beach plum mixture, because this will make your final jelly murky.

Rolling Boil, fire and brimstone style.

Hopefully this effort will yield a solid four cups of beach plum juice. Clean out the pot and pour the 4 cups of juice in with the 6 & 1/2 cups of sugar. Bring the mixture to a rolling boil. When I say roiling boil, I mean fire and brimstone – like the jelly rears up in the pan.  Reduce heat and then add a full package of Certo®. Bring entire mixture to a rolling boil for one solid minute.

Test your jelly for done-ness using the plate in the freezer method.  (I don’t mean to be a jam snob, but If you don’t know the freezer plate method, you probably should practice making jam on an easier fruit. Here are some tips.)

If jelly shows it’s set, pour into pre-boiled 4 or 8-ounce jelly jars, leaving a half inch of space on the top. Seal jars and put in boiling water for five minutes. (I haven’t gone into detail on all the safety measures that go into preserving jellies, it’s called botulism baby. If you aren’t skilled, I suggest spending some time on the Ball Jar® website which has an elaborate section on dos and don’ts of jamming. Remember, even the most skilled preserve maker occasionally has a fail.

Don’t panic if your jelly doesn’t set right away. I find it takes a good week to fully gel. Enjoy beach plum jelly on a piece of rye toast or dab a bit on goat cheese. It’s tart and tangy and simply divine.

And if that sounds too complicated, I have an excellent solution. Reach out to Linda Alley at New Lane Sundries, she ships her jams and jellies all the time!  You can also find her at the West Tisbury Farmer’s Market every Wednesday and Saturday. And if you manage to make a successful jar, let’s make a trade. I’ll send you some of my iconic “Georgia is Blue-berry jam” in exchange for your beach plum jelly1