Hal Varian writes in in comments:
Paul Samuelson used potatoes as an example of a Giffen good in his Principles of Economics book and drew the well-known implication that they must therefore be an inferior good (i.e., the demand for potatoes falls as income increases.)
One year he got a letter from the Maine Potato Grower Association along with an econometric study that they had commissioned that showed that, in fact, potatoes were a normal good. They suggested that he find some other example to use in his textbook.
So what is it about you economists always bad mouthing potatoes?
Shouldn't that be "we" economists, kemosabe?