Scents definitely will go bad. I had a bottle I would use every now and then. I was fishing with my buddy one day and he asked me about the scent. He picks it up and smells the bottle and about pukes. The stuff smelled like week old road kill, and Ive got no idea how long it had been like that or how on earth I never noticed it. I check my bottles carefully now.

I really like the LPT from YUM, especially when bed fishing. Only problem is I use white baits, the scent is sorta red/pink, and it stains my white baits (they may offer other colors now, havent checked in a while) but for other baits its fine.