As stated, store it right and good to go, I have 6 gallons right now that is at least 5 years old. It is inside and in the dark and just like I purchased it. If you want to see it you fuel has water in it let it freeze, guess what, the water will rapidly show! Actually a small amount of water seems ok if you shake up the fuel, jet liners use agitators to keep jet fuel and water mixed to get a clean burn, it like glow fuel will become water laden if exposed. Diesel fuel behaves much the same........