Adithya Sambamurthy/The Bay Citizen

This white bean, kale, tomato and sausage stew was traded at a recent food swap at 18 Reasons

After all, she was inviting them to feed their children meals, including roasted pears and curried lentils, made by people they did not know.

But for parents interested in consolidating food preparation while providing organic, homemade food to their newborns — as well as some impromptu parenting advice — Solomon’s swap at 18 Reasons, a nonprofit food center in Mission Dolores, was just the thing.

“Most mainstream baby food just isn’t very appealing,” said Solomon. “Anything that saves young families any amount of time is enormously valuable.”

Solomon’s event, which is now more than a year old, is one of a number of food swaps popping up around the Bay Area. Taking cues from the food co-operatives of the 1970s, these urban dwellers are restructuring their food economies around face-to-face relationships.

In San Francisco, 18 Reasons, which is affiliated with Bi-Rite Market, is the swapping hub. In the East Bay, the backyard-fruit-focused group Forage Oakland has been host to several produce and preserve swaps, and two new series begin in April: the Homemade Food Swap from East Bay Swappers, led by Kendra Poma, and the Belly to Belly Bartermart, hosted by Ellen Johnson, a chef who is host to underground dinners made with local, seasonal foods.

Some have termed the swaps “collaborative consumption”— a new, tech-savvy angle on the familiar idea that sharing and trading is crucial to creating prosperous communities. Clothes swaps, co-working and car shares are among the most visible forms of the new sharing economy, with sites like thredUP (for children’s clothing), RelayRides (for cars) and Sharable.net (everything from bikes to data) gaining traction nationally.

Food sharing is an inherently personal form of collaboration; it is hard to quantify because most swaps occur privately. But thanks to social media and a resurgence in urban food production and preparation, it is now fairly easy to set up more formal exchanges.

No money changes hands at food swaps, and thus far, public food swaps have not been subject to Department of Public Health regulations, as underground restaurants and food markets are.