I would assume if the fuel was stored in the proper manner it would be O.K., but take note to the word I used ASSUME since I do not know any facts about this.

I am also old school I guess because I see where some people use two or three types of fuel for the same plane/engine because one may be cheaper today than the last brand they bought last time. Myself I think once you start using a brand and nitro% you should stay with it if it is working good for you.