Just a little something I do with storing my Nic guys, I keep a big 250ml & 500ml bottles in the freezer sealed with heat shrink wrapping the lids, I pour 3 x 30ml bottles from the 250ml bottle and use all 3 x 30ml bottles First, then refill these 30 ml bottles from the bigger bottles always, thus having to open my bigger bottles less often, just how I do it. I also shrink seal ALL my bottles not in use the bigger ones. This way less opening of the bigger bottles, less light and oxygen getting to them the better.