I keep kosher, so I can't partake in any part of a pig, which unfortunately includes its lard. But I was wondering if I can use duck fat as a substitute for baking (savoury) pie shells, biscuits and the like. I understand it might taste quite 'ducky', but as a topping for pot pies or an accompaniment to eggs and potatoes at breakfast, I wouldn't mind. What I'm more concerned about is the differences in pig lard and duck lard when it comes to the baking process. Do they break down differently?