You are right by the fact that "spelt" is a form of wheat.
But when you look at these links, I'm sure that you
will be both astonished and shocked.
http://dictionary.reference.com/browse/spelt
This is the meaning of "spelled".
http://dictionary.reference.com/browse/spelled
It said that "spelt" is the past participle of spell, while "spelt" and "spelled"
have the same meanings.
In other words, I'm right and you called the wrong person foolish.