On a recent evening, Jhos Singer could not be found at the JCCSF or Congregation Chochmat HaLev — his usual haunts — but instead was behind the bar, muddling aromatic herbs like basil and mint with citrus, adding various spirits and bitters, and shaking vigorously.

It wasn’t really a detour from his Jewish interests as much as it was a merging of his passions. Mixology has become quite the hobby for Singer — an educator at the JCCSF and the maggid at Berkeley’s Congregation Chochmat HaLev — and with Tu B’Shevat approaching, Singer offered a holiday-inspired lesson on the art of mixing cocktails.

The event took place at the Battery, a posh, members-only club in San Francisco, as part of the JCC’s pop-up series held at outside venues. The following week, Singer mixed cocktails at Tiburon’s Congregation Kol Shofar in a fundraiser for the Sarah Bendiner Fenner Fund, a new initiative of the Bay Area Jewish Healing Center to aid families with young children who are touched by cancer.

Speaking to the group at the Battery, Singer said his interest in mixology isn’t so curious given that he once worked as a cook and later wrote his master’s thesis at the Graduate Theological Union on the history of Manischewitz wine — “arguably the most ridiculous joke of a wine ever created; it tastes like purple bubble gum.”

The story of this Jewish wine, he said, goes back to the days of Prohibition when Jews still needed wine for sacramental purposes. In the years leading up, there was no wine culture in America to speak of, and most of the grapes grown in American soil gave off a “foxy” scent, meaning redolent of wet fur.

The Jews realized they could solve the problem by adding sugar — a lot of it. “No one would have been interested in it if not for Prohibition,” said Singer, a natural storyteller who went on to recount some lesser-known history of Tu B’Shevat.

The holiday has biblical roots, but celebrating it fell out of favor when Jews could no longer possess land. It was then repurposed by Jewish mystics in Tsfat to become the birthday of the tree of life. While the seder at Passover is much more widely celebrated, the mystics also came up with a seder aligned with this agricultural holiday. It tells of the four worlds of creation: the physical, the emotional, the intellectual and the spiritual.

“We’re going to riff on a Passover seder, which can sometimes take six hours, by fast-tracking it into a cocktail,” said Singer.

I was in my late 30s before I ever actually enjoyed alcohol.

In a follow-up email, he explained that his interest in mixology started when he was a student at UCLA and worked for a catering company. He didn’t drink then — he had grown up in a home with alcoholism — so he was often tasked with mixing the batch cocktails and working the bar, since he could be reliably trusted to do so.

“I was in my late 30s before I ever actually enjoyed alcohol,” he said. Once he established that his genetic history did not put him at risk for alcoholism, he found he not only enjoyed drinking but also liked mixing, too.

“I love the alchemy of turning hard liquor into something with complex, nuanced flavors and also beautiful to look at — and since I didn’t want to do it professionally, I figured the best way to learn was to use my existing set of kitchen skills and study the master mixologists on my own.”

At the event, Singer offered a tip that every home bar should have at least three types of bitters: Angostura, orange, and Peychaud’s or Creole.

Four stations had been set up according to the characteristics of the four worlds. For example, since the spiritual world was about essence or fragrance, there was basil and mint. The other worlds were represented by citrus slices, pineapple chunks, strawberries, blueberries, cucumbers, mango chunks and olives.

Participants gathered their chosen ingredients on a small plate and took them to the bar, where Singer and another bartender asked about their preferred spirits and cocktails and then used the ingredients to make up an original cocktail on the spot.

Every participant I spoke with loved the result, and certainly people who came for the cocktails left a bit more knowledgeable about Jewish mysticism, too.