I only have one russian tortoise, and since I try to vary her diet a good bit, by the time I'm a third to halfway through a bag of spring mix it's starting to look pretty nasty-ish. I've been storing it just in the packaging bag in the vegetable crisper drawer in my fridge. Are there any tricks to maybe making it last a bit longer? I doubt it freezes well, but maybe if I put it in a bowl that's not covered so it doesn't get slimy as fast? Anyone have any tips or tricks?