I just crafted me some new items, and wanted to enchant them.
But I encountered an issue I dont quite understand.

I have an enchanting skill of 80+, I have plenty of soul gems of all kinds, but it will not let me use the best gens even though I have enough.

I could enchant 3 items with grand soul gems, then the rest I can only use petty soul gems with.
I see this all the time, even though I have plenty of gems of all kinds, I can not always use the best ones.

But if I wait a while and come back later I am sometimes able to use them after all.

The the enchanting workbench have some kind of charge I have to wait for or is there a limit to how much I can enchant?
Or how does this thing actually work?