When Rahel Lerner was growing up in Teaneck, New Jersey, turkeys were nearly everywhere she looked on Thanksgiving. Turkeys adorned the napkins on the table, turkey-shaped candles flickered, and, one year, the family feasted on a carved chocolate turkey. The only thing missing was an actual turkey. That’s because, as Lerner told me recently, her family refrains from eating the fowl, which, due to an obscure rabbinic dictate-turned-family-tradition, was considered in her household to be trayf.Lerner, now 34 and married with a child of her own, is a descendant of Yom Tov Lipmann Heller (1579-1654), better known as the Tosfot Yom Tov (the title of his tract on the Mishnah), who was the chief rabbi of Prague and went on to head the rabbinical court of Krakow. According to Lerner family lore, he declared that turkeys were verboten and that none of his descendants should eat the animal. Lerner’s extended family continues to observe his edict, though they wholeheartedly embrace turkey kitsch when the fourth Thursday of November rolls around.The debate over whether turkeys were kosher didn’t emerge until the birds, indigenous to the Americas, were introduced in Europe in the 16th century. Fish and animals must meet certain specifications in order to be deemed kosher (fins and scales; hoofed feet, chews its cud). For birds, by contrast, the Torah simply lists those that Jews are not allowed to eat, and these are mainly birds of prey. Turkeys were not on that list—they weren’t known at the time. But according to Gil Marks’ Encyclopedia of Jewish Food, the bird was ultimately accepted as kosher: a really big bird.Yet the Tosfot Yom Tov refused to budge. Lerner admits she doesn’t actually think turkey is trayf. Rather, her refusal to eat comes out of respect and pride. “It’s a family thing far more than a Jewish thing,” she clarifies. And, she admits, it helps that her husband is a vegetarian.