Ryan, bacon grease from grain fed pig meat is high in polyunsaturated
fats. These are not particularly stable and oxidize easily. Oxidized fat
is definitely not healthy. I would not use old bacon fat. I would use
bacon fat that is brand new, or that has been refrigerated. I am not
crazy about using bacon fat even here, because it has already broken
down from cooking, I believe. Beef fat, chicken fat, goose fat, are all
highly stable even at high temperatures and would make great cooking
fat. I just rendered some beef fat last night that I plan to use.

(Thanks to Adele for pointing out that I should have known better and
should not have been using butter. Not only non-paleo, but I am very
dairy allergic and somehow thought that becuase it has very little
"foreign protein" I would get away with it. So I am going to be cooking
a lot with animal fat from now on.)

Just a thought.

--Richard