Michael Quinion says he has solved the mystery of the red herring—how the phrase “red herring” came to have its current meaning:
The matter is now cleared up as the result of a pair of articles in the October 2008 edition of Comments on Etymology, edited by Professor Gerald Cohen at the Missouri University of Science and Technology. One article reprints notes Prof Cohen made on the term in the same journal in 2000, the other is by Robert Scott Ross, who suggests a plausible origin for the expression. Their findings are supported by the Oxford English Dictionary’s revised entry for red herring, which is to appear online shortly….
The retrieval of that explanation we leave to the reader as an exercise.
BONUS: We leave as a further exercise for the reader the finding of the answer to the question “Who is the editor of Comments on Etymology“?
BONUS: A recipe for red herring: