If they smell like veggy oil toss them.One way to keep them fresh and last longer is to keep them in the frid when not in use.I also try not to buy to much at one time.I buy my scent for the fishery that I'm fishin only.Like Steelhead season I'll buy some pro-cure shrimp oil and some shrimp glo smelly jelly,this will get me through winter runs.Then for springers I'll buy some special mix.I will run through these scents before buying more.Good luck,
STRIKE ZONE