“I don’t know what I want; there’s a lot of options,” said Lauren Maghini, staring into a cold case of sandwiches while holding a basket filled with bags of bulk rye berries, garbanzo beans, popcorn and green lentils, along with burritos and rice cakes. “Even though there are some grocery stores that are local to where I am,” she said, noting that she had come from Wallingford, “they have a wider variety of a lot of organic free-range, antibiotic-free, local produce here.”

As much as co-ops like to talk about their community roots and local job creation, Ms. Maghini’s reasons for co-op shopping were by far the most often cited.

On a late February afternoon at the Willimantic Food Co-op, Sharon Williams of Windsor Locks was on her weekly visit for 10 half-gallons of raw milk, and Kathleen King of Columbia, an eight-year member, was loading up on faro, garbanzo bean flour, sunflower seed butter, kale and daikon. “I’m vegetarian and I can’t eat soy products,” she said. “I can find a lot more things that I can eat here.”

After 32 years in business, Willimantic’s active membership is around 6,000. Customer demand for local meat forced the store to give up its vegetarian status last year; bulk offerings have increased by 10 percent to hundreds of items: 10 flavors of cashews, including maple, garam masala and nori sesame; 22 rices; two-dozen beans; 10 trail mixes; the requisite coconut; and of course those elusive kamut nuts. “I think that the interest in co-ops and product availability has totally increased,” said Alice Rubin, Willimantic’s general manager, who has worked at the store since 1984. “But now the competition has increased, and that’s a whole new twist.”

The surge is significant. Stuart Reid, executive director of the Food Co-op Initiative, said there are about 325 food co-ops nationwide, about 50 of them new in the last few years, and he was working with another 200 communities on new co-ops. Erbin Crowell, executive director of the Neighboring Food Co-op Association, said one-third of his 28 members in Connecticut, Massachusetts, New Hampshire and Vermont are startups. Both said the corporate aversion that has been propelling Occupy Wall Street is also buoying co-ops. The people who shop at co-ops are also the owners, Mr. Crowell said. “There is an extreme level of loyalty you don’t see in other businesses.”