An Etymological Dictionary of the German Language/Annotated/Küche
Küche, feminine, ‘kitchen,’ from the equivalent Middle High German küche, küchen, kuchîn (Upper German without mutation kuche, kuchi), Old High German chúhhī̆na, feminine; corresponding to Anglo-Saxon cyčene, feminine, English kitchen, Dutch keuken. An old West Teutonic word, probably not derived immediately from late Latin coquîna, ‘kitchen,’ but rather from a common Romance and Middle Latin cûcina (kukī̆na; compare Italian cucina, French cuisine). The High German ch (Old High German hh) for c, k, in consequence of the High German permutation points to the adoption of the term about the 6th century, at which period the South European arts of cookery and horticulture were introduced into Germany; compare Koch, Kuchen, Kohl, Kümmel, and Pfeffer.