This is not to contradict anything in your piece but just in case anyone else here likes useless bits of information (what do I mean, “in case”??). I remember reading in an interview with or article on the late Arthur C Clarke where he mentioned that the great scarcity and relative strangeness of naturally blue foodstuffs inspired the use of that colour for all of the food found by Dave the astronaut at the end of his trip through the Star Gate.
Thanks for all of the great items over the years. Please keep up the good work of educating the teeming millions.
Welcome to the Straight Dope Message Boards, PAUL S, we’re glad to have you with us. When you start a thread, it’s helpful to other readers if you provide a link to the column under consideration. Saves search time, and avoids repetitions, and keeps us on the same page. I’ve added the link at the end of your post; no biggie, you’ll know for next time. And, as I say, welcome!
For the rest of you: Folks, this thread is in reaction to a column by Cecil. There’s no need to repeat information already covered in the column (like blueberries and blue cheese, say.)
Forelle (raintrout), Karpfen (carp) and Felchen (powan aka cisco) blau: If you cook these fishes in water with some vinegar their mucosal skin turn into blue.
It is a delicacy from Switzerland, Austria and the southern states of Germany served with boiled potatoes and melted butter.