I have had fuel that was around 15 years old, it had been opened but put inside a closed cabinet in a garage all that time, it was just fine. The garage was unheated and it was in the central valley of Calif. The fuel was in clear plastic jugs. I just didn't see a lot of daylight over the years. My own fuel I buy is in cans, light has no effect on it at all. It's in a cool dry place, my shop. My shop runs from 100 degrees in the summer to 30 degrees in the winter and all points in between. People in other parts of the country may have problems with condensation but if kept in a dry environment there shouldn't be any problem. How you store your fuel is the key. Even storing my fuel in an unheated shop when I lived in the mountains created no problem. My unheated shop there was nice and dry. One good way to test your fuel is to put in in a plane and fire it up and run it. If you have moisture in your fuel your engine isn't going to run. If it fires up and runs then you have no problem. Other then moisture the nitro, oil and alcohol isn't going to go bad over time. It either works or it doesn't.