My partner worked at a water bottling station and they kept a “dead archive” of production for quality control: dark, cool room, away from machinery and chemicals.
Archived samples were cleared after 5 years. Out of curiosity, they decided to try the water before emptying the bottles and it was foul. Blamed on too long storage time.
When the plant shut down, the archive was fully cleared and samples older than 6 months were drinkable but not pleasant to, older than a year tasted bad.
Water does not stock well and even worse when exposed to sun light.