"Melmelada de tomàquet is not so much a tradition as it is a necessity," says Georgina Regàs, the creator of Catalonia's Museu de la Confitura.

"You know how tomatoes are, they come in such overabundance." That's easy for her to say. She lives in l'Empordà—a kitchen-garden-rich corner of Catalonia with a ridiculously long tomato-growing season. No one on my cold New England sandbar would dare to speak so casually of that kind of success with tomatoes, for fear of being struck down by blossom end rot.

But this year we did have tomatoes. And once the thrill of tomato sandwiches (thick slices, white bread, mayo, salt) eased up, the season kept on long enough to allow us to act like Catalans. That is, pa amb tomàquet for breakfast, lunch, and dinner. Until I remembered the tomato jam with locally made fresh cheese at Georgina's little confiture workshop in the village of Torrent.

When I called, she didn't really want to talk about tomatoes. She was gearing up for her autumn classes. "The madrones are so beautiful right now. They say if you eat them in full sunshine, they'll get you drunk. Plus, they're loaded with pectin." "Wait a minute, is madrone jam traditional in Catalunya?" I've seen madrone trees there and in California, but I never knew those little orange fruits were edible. "Probably not," she says. "Catalans are not really a serious jam-eating people. But I'm into the recovery of the art of preserving. I'm not interested in limiting myself to traditional Catalan jams."

Georgina started her museum after an English visitor turned her on to lemon marmalade as a way to use the fruit that was littering her dooryard. "This project is more about nature's treasures than it is about national ones."

I think maybe Georgina is herself a Catalan national treasure. She is 79 years old and started this project just seven years ago. She does have a business partner, Teresa Millàs. "I had to cut her in," she says, "Because I'd go to the bank for a loan on kitchen equipment and they would say I needed someone who was going to be around a while to back it up." "But really," she goes on, "the only part of this I'm too old for is Facebook. I've lived my whole life without it just fine." (Nonetheless, you can "like" the museum here.)

Teresa and the rest of the museum's small staff all share Georgina's passion for preserving and teaching. And in spite of their prize-winning forays into foreign jams (they won a gold medal for their kumquat marmalade at the Dalemain Marmalade Festival last year, which landed their jars on the shelves of Fortnum & Mason in London), they do teach classics from her region, including tomato jam.

Georgina approves of my totally simple recipe, though she would add an apple to the pot. Its pectin will make the jam set faster, which she says translates into fresher flavor. She also recommends another combination locals are fond of: tomato-watermelon jam. Both are traditionally eaten alongside fresh cheeses for breakfast or for a mid-afternoon snack. A smidge on a cracker loaded with goat cheese makes a nice American style hors d'oeuvre.

I predict we'll soon see see tomato jam as part of a fancypants restaurant dessert in New York or Barcelona. I imagine it alongside, say, basil ice cream, with a drizzle of arrop.

"After the war, when nobody could afford sugar, preserves were made with arrop—grape juice, boiled into a thick, slightly caramelized syrup," Georgina says. "But yes, I hear arrop is in fashion again."

Melmelada de Tomàquet—Tomato Jam
makes about 4 half pints

3 1/2 lbs perfectly ripe plum tomatoes
1 1/2 lbs sugar
1 oz (two tablespoons) freshly squeezed lemon juice
a big pinch of salt
a sprig of fresh thyme

Blanch the tomatoes for half a minute in boiling water. Then peel and core them and drop them into a large, heavy jam-making pot. Add the sugar, lemon juice, salt, and branch of thyme.

Bring to a simmer, then a steady boil, stirring every few minutes. Watch the jam closely as the water cooks off and the juices become syrupy: you'll need to stir it steadily to make sure it doesn't stick to the bottom of the pan. Squash any big chunks of tomato while you're at it. Skim off any sticky foam that forms on the surface, too, since those dense little bubbles will cloud the jam's sparkle later. The jam will begin to set up in about 25 to 35 minutes.

When it's softly set, remove the thyme and ladle the jam into clean hot jars and seal.

If you need instructions on testing jam for doneness or on preparing, sealing, and processing your jars properly, the people at Ball jars are more than happy to tell you what to do.

El Museu de la Confitura is on the Plaça Major in the village of Torrent, Tel: +34-972-30-47-44. Summer classes are for kids, but during the rest of the year, the museum offers classes for adults, about once a month. A typical Saturday class covers techniques, hands-on preserving, and a light tasting menu that can stand in for lunch. Don't be afraid to join a class just because your Catalan is rusty: Georgina speaks Spanish, French, and English and, besides, when people are cooking, they nearly always understand one another. Coming up, Saturday, October 4: madrone jam and picapoll grape jelly. Winter classes move on to preserved pumpkin, and for the holidays, there's Cava jelly, and citrus marmalades.