More out of curiosity than anything, when would one use "burnt" and when would "burned" be appropriate? For example,
This coffee tastes burnt.
This coffee tastes burned.
They burnt the coffee again.
They burned the coffee again.
Does it make a difference? I know when I speak either phrase they sound almost indistinguishable (my "t"s do not always sound sharp and come across like "d"s at times); can they be used interchangeably?
[ As an aside, the problem with the coffee at the local Dunkin Donuts is what prompted the whole curiosity about this :) ]