I haven’t been putting plastic film on top.
It’s usually in plastic containers with lids, or little Pyrex bowls, with plastic wrap on top, but not touching the fat.
I am at the super taster end of the spectrum. Very sensitive to fat that tastes rancid, whether it’s nuts, sesame seeds, peanut butter, pork fat (in frozen bacon or sausage), poultry fat (in turkey sausages or duck fat).
Or, maybe my freezer is part of the problem. Even though it’s the type you need to defrost every so often, that the salesman told me would help keep frozen food stay fresher longer, the frost builds up quickly, so it might not be consistently cold enough to prevent some fats from oxidizing.
I don’t like duck fat enough to work on its preservation. I make duck legs every 6 weeks or so, giving me another cup of duck fat that I will keep in the fridge until I need space.
Virtually always using olive oil here. Schmaltz if available. I don’t eat bacon and rarely have duck fat around. Sometimes I’ll toss a little butter in with the crispy potatoes in the cast iron skillet at the end.
I picked duck fat for the roasting, but could also have given the nod to schmaltz (I just am more likely to have duck fat in the freezer). On the other hand, for firm, mild fish I like a combination of olive oil and butter.
I answered duck fat but I don’t usually have any so use a neutral flavored vegetable oil. When I have it I only use duck fat with potatoes. With most other vegetables, I want a lighter flavor than duck fat.
Duckfat for sure, and butter is a close second. But I find bacon fat too bacon-y for most applications. As much as I love bacon, I don’t want all my non-bacon foods to taste like bacon.
