At the dawn of the 20th century, observant Jewish women made pie crusts and other pastries using rendered chicken fat as shortening! They actually fried chicken skins until yellow fat oozed into the pan — which sounds so savory and Old World. But this shortening complied with the Kashrut Laws, which forbid mixing dairy products and meat at the same meal. Because butter wasn’t an option for kosher housewives serving meat, what else could they do but turn to schmaltz, glistening chicken fat? In 1911, Crisco burst on the scene as an all-vegetable shortening. Procter & Gamble, its manufacturer, proudly...