Interesting findings Rob, I do like to keep my base in the fridge, sometimes up to 6 days and I find the flavour very good.
For storage I use an IceCream tub with lid on, how did you find the ajwain worked in the base? I find it has a strong flavour that penetrates.
I first discovered this spice in my mushroom fried rice when visiting North Wales, very nice report looking forwards to more of your findings.