Here is the story of my first, traumatic encounter with a Jell-O mold.

I ate Jell-O, of course — it was the first thing I learned to “cook,” in a dedicated set of Tupperware bowls. Its bright primary colors sparkled in glass coupes at every coffee shop in the city, and it had a taste of forbidden fruit, like melted hard candies. With a crown of whipped topping, it was considered a luxurious dessert.

But in my 14th year, the Jell-O paradigm shifted. My pack of friends was invited to dinner at the home of another friend; her mother, a transplanted Southerner, had already set the table with the first course. All of us New Yorkers stopped dead, goggling at plates that held individual molds of red Jell-O topped with a dab of something too yellow to be Cool Whip.

Someone blurted out, “If that’s mayonnaise, I’ll choke!” Naturally, this was greeted with shrieks of laughter. With ice water in her voice, the heroic hostess simply said, “You can scrape it off if you don’t like it.”

I remember eating the rest of the meal in silence, cheeks burning with shame. Still, I wondered: Why was dessert served as an appetizer? Why was it topped with sandwich spread?

I had stumbled into the eternal conundrum of Jell-O: Is it a salad, a dessert or somehow both?

This time of year, many Americans have Jell-O molds on their minds. Jell-O consumption has gone down steadily since its peak in the mid-20th century, but many cooks bring back a favorite dish in this category for the holiday table. Whether it is called a Jell-O mold or a congealed salad, or has a given name like Golden Glow Salad, Celery Nut Circle or Strawberry Pretzel Surprise, it is usually sweet and tangy, sometimes creamy or salty, occasionally crunchy and briny.

But even those who love them are not always sure what they are.

“It goes on the buffet with the turkey and the ham, and it stays through the pies,” said Jeffrey Zweben, a lawyer in Atlanta. He ignores Jell-O for most of the year, but starts stockpiling his favorite, the hard-to-find black cherry flavor, in September. For his signature Thanksgiving mold, he combines it with whole cranberries, crushed pineapple, cream cheese, whipped cream and — of course — a tablespoon of mayonnaise.

“It goes with everything,” he said firmly. “Jell-O is a processed joy.”

But do all Jell-O molds evoke joy? A spin through The New York Times Food library turned up a Mormon community cookbook recipe with lemon Jell-O, canned tuna, canned condensed chicken-and-rice soup, salad dressing, whipped cream, celery, peas and walnuts; a 7Up Cheese Aspic with lime Jell-O, 7Up soda, grated onion, diced Velveeta, celery and olives; and a corned beef loaf with lemon Jell-O, for which there are no words.

It took more than 20 years for me to exorcise and explain that first Jell-O mold encounter. The process began at luncheon at the Woman’s Club in Richmond, Va., where each guest received an exquisite plate: a half-moon of red Jell-O surrounded by cheese straws, cream cheese-stuffed celery sticks and a scoop of chicken salad.

I loved this meal, but I still didn’t understand it.

I tried. I learned that gelatin salads flow from the traditions of Edwardian vegetable aspics; of ancient, naturally gelled bone broths; of European classics like jellied meats and Bavarian cream and blancmange. I learned that the United States is far from alone in its dedication to jellies: grass jelly in China, kanten in Japan and gulaman in the Philippines are all made from agar, a bouncy gelling agent extracted from algae.

I learned that sweet, cheap, instant Jell-O was a dessert that truly reflected the Space Age, that its artificial qualities were part of its appeal.

I learned that women who were nudged back into home kitchens after World War II brought their pent-up ambition and creativity to the new phenomenon of “entertaining,” and that a molded salad could be seen as a metaphor for how women of the era were supposed to be: well-contained, bright, pretty and resilient.

“A salad at last in control of itself,” is how historian Laura Shapiro described Jell-O molds in “Perfection Salad,” her book about American cooking at the turn of the 20th-century.

The book is titled after a popular concoction of lemon Jell-O with shredded cabbage, carrots, celery, peppers and pimento-stuffed olives. (The recipe won third place and a sewing machine in a 1904 Knox Gelatine contest, and was published in its booklet “Dainty Desserts for Dainty People” in 1915.)

Kitsch is definitely part of the Jell-O-mold conversation.

Victoria Belanger, the self-proclaimed Jell-O Mold Mistress of Brooklyn and an expert in the gelatinous arts, said that among fans of her work, “there’s a kind of ironic attitude toward Jell-O molds.”

She said the tradition has recently morphed again among younger cooks, who make fancy dessert Jell-O shots in flavors like cranberry spice and apple pie a la mode. Modern holiday Jell-O-shot recipes are layered like parfaits and garnished like craft cocktails, with herb sprigs and sugar-frosted cranberries.

Ashley Baker, a law student in Colorado, planned pumpkin spice Jell-O shots for her holiday table.

“This way I don’t have to make pumpkin pie,” Baker said. “No one ever ate it anyway.”

CHERRY-LEMON CREAM JELL-O MOLD

By Julia Moskin

>> 1 large (6-ounce) package lemon Jell-O

>> 4 cups boiling water, divided

>> 1 (16-ounce) container sour cream

>> Neutral cooking spray

>> 2 large (6-ounce) packages black cherry Jell-O, or use plain cherry or cranberry Jell-O

>> 1 quart sweet or tart cherry juice, or use cranberry juice (opt for less cloudy varieties)

>> Fresh holly sprigs, bay leaves or edible flowers, for garnish

>> Pour lemon mix into medium bowl, add

>> 2 cups boiling water and stir until dissolved. Let cool about 10 minutes.

Gradually whisk in sour cream until smooth.

Spray a 10- or 12-cup mold or Bundt pan, very lightly with cooking oil spray. Blot extra oil with paper towels. Pour in lemon mixture and refrigerate until set, about 1 hour.

After about 45 minutes, pour cherry mix into large bowl, add 2 cups boiling water and stir until dissolved. Stir in cherry or cranberry juice. Let cool just to lukewarm.

When lemon mixture is set, gently ladle cherry mixture over it (don’t pour it on, as mixture breaks easily). Refrigerate again until completely set, at least 3 hours.

When ready to unmold, run tip of a sharp knife around edge of the pan. Dip bottom half of mold in warm (not hot) water for 15 seconds. Place a serving plate over top and flip to unmold. (If the mold doesn’t come out immediately, don’t shake it; try the warm water treatment again, 15 seconds at a time, until it comes out. Don’t let mold sit in water longer or it may start to melt.)

Garnish, then use sharp knife to slice, wiping blade between slices. Serves 10 to 12.

Nutritional information unavailable.