This is something that I just ran into...
I've had a can of crisco that I've had for several years for muzzleloading purposes. I have a thing that I use to squeeze the grease out of made of brass onto the balls in the cylinder so I don't even have to handle it, and I've melted the crisco slightly in order to pour it into the brass squeezer, and pout what I didn't use back into the can. I've done this for several years and really helps keep me shooting quickly and with little mess.
Anyway, it's started to smell kinda bad- just ever so slightly when close to it.
The crisco looks like mayonnaise that's been left out too long- kinda translucent. I got some of it on my hands and it's much harder to wash off and is far more sticky than usual.
I'm going to continue using the stuff even if it does smell a bit, or until my shooting buddies complain about the smell or I can't stand it.
I'll likely have it shot up in another year and have to get a new can anyway.
Maybe I'll just stir in some mint tincture to cover the smell.
I'll try the butter flavored crisco next time.
Maybe it'll smell better.