John Hurley and Justin Hafen tried comfort food. They tried gourmet. They tried deli. They tried Asian. And now, they’re done.

After operating four less-than-successful restaurants over the past three years at the Jewish Community Center of San Francisco, the pair of restaurateurs have decided that this is a riddle they cannot solve and are leaving it to someone else.

The California Deli and 415 restaurant served their last hot meals in late May before Hurley and Hafen sold all of their assets — the kitchen equipment, liquor license, furniture and even the salt-and-pepper shakers — to the JCC.

“There’s not one reason. It was 1,001 things,” said Hurley when asked why he could not find success at the JCC.

“I can’t say it’s the location, the food or the service. If I knew what made a restaurant a success, I’d be a billionaire. You just never know.”

Aaron Rosenthal, the JCC’s communications manager, confirmed that the JCC did buy the restaurants’ assets, though neither the center nor the restaurateurs would disclose the price.

The JCC is extensively polling its membership as to what sort of restaurant they’d like to see in the site, an advantage Hurley and Hafen did not have when they opened up three years ago. Readers can still add their two cents at www.jccsf.org/restaurant. So far, 1,200 people have offered their opinions.

Between completing the poll, negotiating with potential restaurant operators and, likely, converting the pair of defunct restaurants back into one space, Rosenthal believes it will be several months, at the very least, before a new eatery opens at the JCC.

Years ago, Hurley opened up Home restaurant at Church and 16th streets in the Castro — you’ll still find it there even though he sold his interests long ago. And yet he found that novelist Thomas Wolfe was right — you can’t go Home again. The second incarnation of Home, at the JCC, failed.

A second restaurant, Sydney’s, failed as well.

Acquiescing to a demand for a Jewish deli, the restaurateurs split the space in half and opened the California Deli and 415, an Asian restaurant.

Hurley said he was surprised, in all cases, how little patronage the restaurants received from the neighborhood community.

While some have weighed in that the JCC ought to be providing kosher fare for its observant diners, even a cursory glance at the San Francisco Jewish community would lead one to believe that this likely would be a chancy business proposition.

Hurley said he “never got much flak” for not being kosher, adding that, with advance notice, kosher food could be provided for observant diners, many of whom brought their own chicken or meat to be cooked.

Egregiously non-kosher items such as pork or shellfish are not permitted in the JCC; 415 was the rare Asian restaurant sans pork.

Both Hurley and Rosenthal said the parting was amicable. Hurley wishes his successors the best of luck — and wishes he had advice for them.

“It’s such a good location. And 4,000 people a day walk through there. I’ve been trying to figure this out for three years.”