In our rough hunting camp we keep a 2-burner Coleman stove as back-up to the propane kitchen stove. One year we had to cook on the Coleman stove for a week as we had problems with the propane.

I do not know how old the Coleman fuel was (it was both in the tank and an open can), I would say over 5 years but less than 10 years. The stove burned poorly, it produced a yellow flame and smoked a lot. After we filled the tank with new fuel the stove ran great, with an efficient blue flame and little smoke.

Mike