Israel has spent more than six decades weaving the two formerly disparate basic branches of the Jewish family, Sephardi and Ashkenazi, into one people. These days, nary an eyebrow is raised as they hang out, date and marry, and most of their cultural differences have nearly evaporated.

But during Passover, the lines are drawn all over again, over something as seemingly innocuous as a bowl of rice —  making for a lively seder debate.

Most Ashkenazim were raised with the belief that, along with yeasty breads, crackers, cereals and other baked goods, kitniyot — corn and rice and all foods made with them, as well as legumes of all kinds (yes, that includes tofu) — are also off the Passover menu. For traditional Ashkenazim, these foods are as hametz (leavened) as a fluffy loaf of challah. 

The Torah itself (Exodus 13:3) forbids Jews from dining on hametz during Passover, as defined as leaven from the “five grains”: wheat, spelt, barley, shibbolet shu’al (two-rowed barley, says Maimonides; oats, says Rashi), and rye. The rabbis in ancient times added to the list anything made from these grains other than matzah and matzah products.

Over the centuries, many Ashkenazim have expanded the list of Passover-prohibited foods to also include peanuts, green beans, snow peas, sugar-snap peas, chickpeas, soybeans, and sunflower and poppy seeds.

But in Israel, with two very different markets to please, packaging can be challenging.

“ ‘Kosher for Pesach for those who eat kitniyot’ is really the phrase you look for [on packaging] so you know not to buy it,” says Arlene Barnhart, an Ashkenazi living in Beit Shemesh. “Sometimes ‘Kosher for Pesach’ is in large letters and the rest is really small. So, even when you have great Hebrew … it can still take hours in the store struggling to decipher what you can and can’t buy.”

There is a subtle shift among many Ashkenazim to say yes to kitniyot: Some mainstream rabbis have ruled that kitniyot foods are acceptable, assuming that the ingredient in question isn’t the main one and is clearly recognizable.

There’s even a Facebook group called Kitniyot Liberation Front that boasts hundreds of followers.

The traditional U.S. Jewish community, meanwhile, is not seeing much of a kitniyot pushback, says Kashrut.com editor Arlene Scharf. And even in Israel, most   traditional Ashkenazim will pass on it at the seder table.

“It’s just something we’ve always stayed away from,” says Rabbi David Aaron, founder and dean of the Jerus-alem-based Isralight Academy of Adult Jewish Studies, adding, “For a week I can live without rice.”