Hi Marissa,
Great questions!
The shelf life of our resin from the date of production is one year. We advertise only a shelf life of 6 months to give customers a bit of a cushion when using up their resin. After the one year, the resin hardener will gradually start to turn yellow. This will cause the resin to cure with a slight yellow tint. The change is gradual and I would say that most people wouldn’t notice, but we want to make sure customers are aware of everything that could impact their resin projects. While the hardener may start to turn yellow, the resin/hardener mix will continue to cure as normal.
Resin (our super clear and others as well) must be kept in a climate controlled environment. It should be kept in a cool, dark place, away from temperature variations. Putting it in a freezer will damage the resin and it will not work once thawed.
Here’s an article on how to store resin:
https://resinobsession.com/resin-frequently-asked-questions/how-to-store-resin/