The differences in copper slags produced at a single smelting site are dependent upon the ore and the smelting process. The problem investigated was whether copper ore containing mainly sulfides could be transferred into copper matte in a first smelting operation or whether the ore had to be roasted first or whether there was only one smelting process allowing a production of some sort of blister copper. The authors' smelting procedure is described; it was determined that only copper matte was probably produced at the smelting site at Jochberg, near Kitzbuhel. The results of the tests, and the possibility of prehistoric copper smelting from sulfide ores are discussed.