ɪn wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti wˈʌn, æɾ ˈeɪdʒ twˈɛnti, kˈɑːk bɪɡˈæn wˈɜːkɪŋ æz fˈɔːɹmən ʌvðə tˈɪnʃɑːp fɚðə hˈɑːɹdwɛɹ fˈɜːm dʒˈɑːn pɹˈɪtslæf ænd kˈʌmpəni.
In 1861, at age 20, Koch began working as foreman of the tinshop for the hardware firm John Pritzlaff & Company.