Rabbi Reuven Flamer remembers the plates and plates of food he saw while he was working for a kosher catering company in Montreal—salty brisket and cholesterol-laden kugel. The food might have been good for the soul, but Flamer could tell it definitely wasn’t good for the body.

“I’ve always had an interest in a more healthy, natural lifestyle,” he says. “I realized a lot of the food being served didn’t fit my values; as you grow in your knowledge, you realize that though it may be kosher, it’s not actually healthy. If someone wanted to mark a pack of cigarettes as kosher, I’m sure they’d find a way. And though something is healthy and kosher, it may not be marked as such.”

The Jewish scriptures outline the rules for kosher food; there are restrictions on which animals can be eaten (no pigs, no fish without scales, i.e. no shellfish), how those animals should be slaughtered, how the food should be served (no mixing meat and dairy). There are also instructions about food made by non-Jewish producers. But as the methods for making food evolve, it takes rabbinical approval to grant kosher status to foods where it isn’t obvious.

And this presents an interesting conundrum: While many non-Jews read the kosher certification as an assurance of healthfulness (think about the Hebrew National hot dog commercials), there are still a number of mainstream health foods that can’t quite break into the Jewish kitchen due to a lack of appropriate labeling or alternative kosher versions. And with trends spreading across health food store shelves, who’s to tell which among the latest miracle foods is actually kosher?

In a Pickle

Fermented foods such as kefir, kombucha, pickles, wine, beer, and cider are hot in health food circles, especially after the 2013 release of the best-selling book The Art of Fermentation: An In-Depth Exploration of Essential Concepts and Processes from around the World by Sandor Katz.

Katz’s concept was simple: “Fermented foods help people stay healthy,” a premise many fans of fermentation wholeheartedly believe. And now there’s actually some science to back up the theories that fermentation is good for our guts (see Feeling Anxious? Have a Pickle.)

Jordan “Uri” Laio is a believer in the power of fermented foods, and he loves kimchi. But as a Hasidic Jew living in Van Nuys, California, Laio had some issues with the kimchi he found in stores. It wasn’t the fermentation itself. While there has been debate over whether the microorganisms in kimchi and kombucha are kosher, Laio’s frustration was was with the shrimp paste and other non-kosher ingredients used to flavor foods after they’re fermented.

To solve this problem, Laio founded Brassica and Brine, a Los Angeles-based food company that’s all organic, raw, vegan, gluten-free and kosher-pareve (meaning OK to eat with milk or meat.) And it goes beyond snacks. For Laio, the company connects spiritual and physical nourishment.

“The way fermentation works is that these microorganisms in the air and on the skin of, for instance, cabbage leaves and grapes, are waiting to get inside, to get at the starches or sugars inside, and to transform them,” Laio wrote on his kosher health blog, Old Growth Yiddishkeit. “When we crush the cabbage leaves and the grapes, we allow those microorganisms access and they, in turn, create a whole new product, much more valuable and special than cabbage or grapes on their own, and yet at the same time, the cabbage and grapes had the spark of potential waiting to be expressed the whole time.”

Certifying GMOs

The intertwining of the spiritual and physical is important to others in the Jewish community as well, including Rabbi Flamer, who currently runs the Natural Food Certifiers (NFC) and administers its Apple K Kosher certification program. Products that meet the NFC’s guidelines for being both kosher and healthy are stamped with NFC’s certification symbol: a stark white “K” drawn inside the lines of a a bubbly red apple.

Flamer started NFC as a way to give a voice to brands and consumers who keep a kosher and a health-conscious diet. In his mind, this excludes not only scripturally-prohibited foods, but genetically modified organisms (GMOs) as well.

Whether GMOs are kosher is still up for debate. According to the Library of Congress, “Israel’s religious kashrut authority has determined that the use of GMO ingredients in food does not affect its kosher status because GMOs are only used in ‘microscopic’ proportions.” But Flamer says GMOs aren’t acceptable in a kosher diet.

“As a certifier, I felt uncomfortable endorsing products with GMOs,” he says. “First of all, the more natural a food is, the better it is for us; you don’t have to tinker with it.”

Amy Rogers, who writes about food, culture, and kosher issues for Charlotte, North Carolina, NPR station WFAE, agrees.

“Modern agricultural technologies are leading to difficult questions about what’s kosher and what isn’t. For example, salmon is a mainstay of traditional Jewish cuisine,” she says. “But when that fish is ‘enhanced’ with GMOs from prohibited foods, it’s no longer allowable. Without GMO labeling, it’s impossible to tell what we’re eating, which creates a real dilemma for people who follow the Jewish dietary laws.”

Flamer says he wants to “put informed choice back on the shelf” with his work. And as our understanding of nutrition and our appetite for new foods change, he’s also making sure souls can keep up with minds and stomachs.