How long can I keep Sterno® on my shelf?
It is recommended replacing Sterno® gel product 2 years after purchase. Always replace cover when not in use. Sterno® is made partly of denatured alcohol which evaporates from prolonged exposure to air.
http://www.sterno.com/faq_gels.aspx?kwid=1&descid=2&pg=faq_gels.aspx
That scratches it off my list then, perhaps that is why I never invested in the stuff. (Having learned and forgotten about the shelf life)