en Cuevana 3. “Kosher”, in a figurative sense, means “pure”. And in the Jewish kitchen, everything that is pure is certified as such by the kosher certificate of purity. In “Being Kosher”, Ruth Olshan applies this Jewish tradition of verifying the purity of things to her own Jewish family history. A tragicomic exploration of Jewish purity laws! From kosher food to ritual hygiene, sex by the book to the “not quite kosher” Jewish identity and family history of the filmmaker.