Although it's common knowledge that the optimal way to store nic base is in glass, with minimal head space, in the freezer, a repeated theme in some of the "stocking up" threads has been that some folks either don't have a freezer at all, or aren't willing to keep their nic base in whatever freezer they do have for various reasons. The question that then arises is: How much difference does it temperature really make? Although I have a dedicated freezer for my nic base, I decided it would be interesting to find out. So... Yesterday, I dug a couple of bottles of nic base out of my freezer. I bought this nic back in April of 2014 (when the Deeming Reg proposal was first published). It came in #1 PET plastic bottles. Since I had not yet started DIY'ing and didn't yet have my own freezer, I stuck them in my wife's big chest freezer "for a rainy day", where they got buried and more-or-less forgotten about. We found them again 2-1/2 years later and they got moved to my freezer with the rest of the nic I'd accumulated in the meanwhile. Given that it was in plastic rather than glass, I was worried that this nic would no longer be any good, so I decided to mix up a batch of my usual unflavored base with it and was pleasantly surprised that the nic was just fine. Anyway, the nic being used in this experiment is a month shy of 3 years old. WL claims to argon-purge their nic, which probably helps, but the dark brown bottles it was in aren't suitable for repeated evaluation of color changes over time, and besides, most people re-bottle their nic in glass prior to storage, so I decided I would re-bottle this in a couple of clear class bottles with polycone caps. Here it is, fresh from the freezer yesterday: I let it come to room temperature overnight, and today, I rebottled it in the clear glass bottles: As you can see, it has just a slight tinge of straw color. The bottle marked "F" is now back in my freezer, while the bottle marked "RT" is on a shelf, at room temperature, in a tin box (to keep out light) with a bunch of other e-liquid. I'll be back to update this thread periodically. My intention is to take pics of the two bottles side-by-side every few months to see whether the one being kept at room temperature changes (darkens) more than the one being kept in the freezer.