If you’ve ever been in a Jewish delicatessen, you’ve probably seen Dr. Brown’s Cel-Ray soda, the celery-flavored soft drink that sounds so counterintuitive yet tastes so satisfying.It’s ubiquitous at kosher delis but hard to find anyplace else.

But there’s another celery soda available in New York, and it’s available at a very different sort of venue: Franny’s, the Prospect Heights pizzeria specializing in artisanal wood-oven pies. The restaurant makes its own simple syrup, infuses it with leaves from the lovage plant (a kind of wild celery), and then mixes the syrup with seltzer to create a drink that’s sweet yet vegetal, earthy yet refreshing. It’s way better than Dr. Brown’s version.

Franny’s is just one of several restaurants around town that offer homemade sodas.The results are uniformly excellent, and there’s no better time to discover these innovative beverages than right now, as the increasingly hot weather makes a cool drink that much more attractive.

If you think soda pop is kids’ stuff, think again. Soda’s origins go back to the late 1800s, when pharmacists were peddling all sorts of foul-tasting elixirs and realized they could make the potions more palatable by mixing them with flavored syrups and soda water. (That’s how soda fountains got to be fixtures at drugstores for so many decades.) Later, during Prohibition, soda became a stand-in for alcohol,which is how we got terms like root beer and ginger ale, along with the cherry-flavored soda brand Cheerwine, which is still popular in the South.

Serious soda geeks, a group in which I happily include myself, can wax rhapsodic — or, okay, pedantic — about all sorts of carbonated arcana, like the superiority of Mexican Coca-Cola (it’s a bit crisper because it’s made with real cane sugar instead of corn syrup) or 7–Up’s original name (Bib-Label Lithiated Lemon-Lime Soda, of course). But you don’t have to care about any of that to appreciate the sodas being served up around the city today.

Most of Jean-Georges Vongerichten’s restaurants feature homemade sodas, including his new venue, Perry Street (176 Perry St., between Washington and West streets, 212-352-1900), where four flavors are available. These are unmistakably adult beverages that have to be sipped, not gulped: The ginger ale and the passionfruit-chili flavors both pack a peppery punch, and the lemon-thyme is as herbaceous as it is tart. The orange-elderflower is a bit muted by comparison, though still delicious.

All of these are made from house-prepared syrups infused with the respective ingredients.”We use the syrups in various cocktails,” the bartender explained one recent afternoon.”But a lot of people just like them mixed with club soda, so we sell of lot of them that way.”

Four flavors are also available at Tigerland (85 Avenue A, between 5th and 6th streets, 212-477-9887), a new Asian fusion spot in the East Village. The best two are the lime and tamarind, both of which are made with fresh juice and organic simple syrup.They’re exactly what you’d hope someone would hand you after a hot afternoon in the sun — or after sampling some of the restaurant’s spicy cuisine. Tigerland also has an excellent ginger ale, which is peppery, much like Perry Street’s. The only misstep is the lychee soda, which is too unassertive and nondescript to compete with the other flavors.

Down at Novo (290 Hudson St., between Dominick and Spring streets, 212-989-6410), a recently opened Latin bistro in SoHo, several soda flavors are prepared fresh daily. A few nights ago, the bartender was serving up passionfruit and blood orange, the latter of which looked particularly appealing as it gave off little iridescent red bubbles. These sodas are closer to commercial varieties, at least in terms of their sweetness — any child would happily slurp them right down. But it’s a bright, non-cloying sweetness that’s miles away from Coke or Sprite. And the fruit flavors explode with each sip.Like all the best sodas, these drinks provide an irresistible mixture of sweetness, flavor, and fizz.

The spiritual godfather of the current house-made soda movement is the Noho Star (330 Lafayette St., between Houston and Bleecker streets, 212-925-0070), whose freshly made ginger ale has been a signature offering for years. Not quite as fiery as the renditions at Perry Street or Tigerland, but definitely stronger than a can of Canada Dry, it strikes a good balance between sweet and spicy. The Star also makes raspberry and black currant sodas to order, but those are prepared from commercial syrups, while the ginger ale syrup is made on site.

“God, we sell so many of these,” a barmaid said as she mixed up a glass for me last week. “People never get tired of it, you know?”

I took a sip — it tasted like summer. “Yeah,” I said. “I know.”