I had an interesting discussion today during lunch on when a food can actually be 'declared' a delicacy. Is there someone saying "this is hereby to be put on the delicacy-list", or is this something that goes by word of mouth? Also, who determines that an item should be classified as this? 
   who determines that an item should be classified as this   You do.   There is no official list of delicacies. No authority on deciding what food is tasty. If, to you, lavender chocolate is a delicacy, then you can say so. Others will say that it isn't, that it tastes like soap and, and they can't bring themselves to eat it. Saying "I like bacon" is just a personal statement about your preferences. Saying "Bacon is a delicacy" is a personal statement which carries a bit more information, namely that you find bacon tasty, but also consider it a luxury food item, as opposed to an everyday food (although this second semantic distinction is somewhat lost nowadays).   As tastes tend to be shared within a culture, you will probably find that the people around you tend to agree somewhat on what is a delicacy, although it's not a complete overlap. This can appear as if there a universal agreement on what is a delicacy. And I don't doubt that somebody, somewhere has compiled something they call a list of delicacies, the same way that a movie fan will compile a list of "really funny comedies". Both have equally little validity - what is funny to that person will not always be funny to you, even though there will be a correlation if you grew up in the same culture.  