Does ESSRI have a shelf life?

[ceebert]

I want to buy some ESSRI. Is it a bad idea to buy, say, a year’s worth at a time? I know the cool-and dark bit, I’ve used Diamine Registrars for a few years, but it’s easy to get, so I’ve always just bought one or two at a time, 100ml. I’d like to buy several bottles of ESSRI, but I don’t want it to go bad and throw away good ink money.