Yes, I think I just made up a word :) What is acceptable to substitute in a recipe. Like for like is the theory but how "alike" really are 2 different food. In a recipe that calls for oranges a reasonable substitution is lemons, right? On the basis of them both being fruits and from the citrus family. You wouldn't use apples? or grapes? or would you?
My thought process right now is regionality, If a recipe were to come to you from far away and all the ingredients were "exotic" would you just not try? or would you substitute? If you never knew the flavor of an orange would you make the leap to a lemon? If you knew only that it was a fruit would you choose a more local or easier to get fruit.
Once upon a time naive me thought that all cheese with holes in it was Swiss cheese, when I moved to Germany I found out I was wrong. There is also Emmentaler and Masdamer and many others. They taste similar and are constructed the same but why are they not Swiss cheese? because they are not from Switzerland. Now I gues sthis should have been obvious to me, but it wasn't. I just never thought of it in that way.
So now I ponder where the food comes from. Cheese, meat, sausage, all of it. What is "local" to where it was made and what is generic enough about it to make it cross regional and sometimes cross cultural.
While watching "Tales From the Green Valley" I realized how it played a large part in their lives. Ruth was making cheese and mentioned that the "cottage type" cheese was one of the few soft cheeses. It seemed wrong when she said it but maybe that was the only type known to the English, this will require delving into. I know though that in Italy there were several types of soft cheeses that are mentioned by Scappi. It seemed reasonable to me that they would be found everywhere. No?
Too much to think about, too much thoughts lead to more research. There are not enough hours in the day.