Remember all that hype about "underground" supper clubs a few years back? They lure adventurous diners into homes and makeshift spaces where fledgling chefs cook up feasts for pay. The hosts trade in secrecy and exclusivity, and play up food specificity with themes like "Pig Every Which Way," "Jewish Soul Food" and "A Taste Of Tripoli" (because there is no Libyan restaurant in town). And, on top of the food, attendees can revel in the novel experience of eating face-to-face, side-by-side with total strangers.

While these dinners may seem like old hat to some foodies, a handful of startups are betting that the concept is just taking off, and see it expanding to a growing number of cities. Here's the skinny on four companies dedicated to helping people find, organize, monetize and manage supper clubs:

Feastly says it's aiming to be the Airbnb of the food world, creating alternatives to impersonal dining the way that the travel rental company has created an alternative market to generic hotels.

"We want to be in every city in the world so wherever you're traveling, you can find a home-cooked meal," Danny Harris, co-founder of Feastly, tells The Salt.

Here's how it works: The site connects chefs (many of them professional) who want to host paid meals or tastings of a new product in their homes with "feasters" looking for a unique dining experience. The chefs set the price of the meal, and Feastly takes a 20 percent cut. Harris says chefs can make up to a few hundred dollars in profit at the end of the night if they play their cards right.

Of course, depending on local regulations, these supper clubs may be illegal. To assuage diners worried about food safety, the Feastly site says hosts "opt in" to its guidelines. But that doesn't mean supper clubs are above health authorities — one in New Jersey was shut down last year because it didn't have a license.

Harris and his partner, Noah Karesh, launched Feastly in early 2012 in Washington, D.C., and recently opened up to chefs in New York. Next month, it launches in San Francisco.

Gusta, another site, operates under a similar premise and has built a network of 287 chefs in dozens of cities from Berlin to Portland, Ore., to Charleston, S.C. Co-founder Carly Chamberlain, a former employee of Airbnb, told Food+Tech Connect in 2011 that it has a more international focus than other sites and can handle multiple currencies.

A newcomer to the supper club business is Kitchen.ly, which, like Feastly and Gusta, provides a space online for chefs to list events and diners to sign up for them. But don't expect to find much on there yet: It held its inaugural dinner in founder Mitch Monsen's kitchen in Ogden, Utah, on Friday. Kitchen.ly could turn out to be slightly more affordable than the others — the site claims that the only charges to organize an event are processing fees of 2.9 percent plus 30 cents.

For chefs and diners who prefer to organize free dinner events on their phones, there's an app for that, and it's called Supper King. A recent search turned up only two events — one in Oakland, Calif., and another in Hamburg. As with all of the services, the trick will be to find enough users to keep people coming back.

Feastly's Harris believes they will.

"There are all of these people out there who want to open a restaurant or food truck but don't have the money to do it, or they have a day job and make incredible vegan food and want to share it," he says. "They just need a platform to monetize their passion, and we believe we'll succeed with that."

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