An Etymological Dictionary of the German Language/Annotated/Koch
Koch, masculine, ‘cook,’ from the equivalent Middle High German koch, Old High German choh(hh); compare Dutch and Old Saxon kok, ‘cook’; adopted before the High German permutation of consonants, at latest in the 6th century (contemporaneously with Küche), when the art of cookery and horticulture were introduced from Italy; the word is based on Latin coquus, or more accurately on the form koko- (compare Italian cuoco). The word passed into English in a different form — Anglo-Saxon côc, English cook, where the ô, compared with High German and Latin ŏ, is due to a change of quantity in an open syllable (compare Schule and Kuchen); on the other hand, the ŏ of the High German word is probably derived from the verb kochen. The earlier Teutonic word for kochen is sieden; an Old Teutonic word for ‘cook’ is wanting. —