The "grape" in Grape-Nuts comes from having contained maltose, the "grape" type of this
[DOC] [TLE] The Straight Dope: How can Grape-Nuts cereal contain no grapes or ... [PAR] Feb 26, 1982 ... ... "grape nuts brand natural wheat & barley cereal," etc., but the type ... (3) In any 
case, how did they come to call them Grape-Nuts?