In 1825 Steinkeller resolved to sell the Niedzieliski business and move to
Warsaw, where he settled permanently. There he continued his pioneering economic involvement in several fields. He opened a large
Department store, imported salt from
England, invested in mining and
Steel production in
Dąbrowa Górnicza, where exploration of deep mining had just begun at
Zagłębie Dąbrowskie. He established a
Brickworks in
Pomiechówek and bought a steam-driven mill in
Solec in Warsaw. He expanded his zinc interests into large-scale production by leasing government owned tin mines and smelting facilities in
Congress Poland. He also imported zinc from the Kraków area, controlled then by
Habsburg Austria. Whereas in
London he set up a zinc works to produce galvanised sheeting and from there he developed an international trade in the metal. In 1838 he set up a
Courier service whose network covered virtually all the main tracts in the Russian-controlled
Kingdom of Poland and outlying areas, using specialist courier carriages he produced at his Solec depot, known as „steinkellerki" – Steinkeller's
Diligence”. He supplemented these with a river courier service. Until the opening of the
Warsaw–Vienna railway of which he was one of the early backers and investors, his messenger network was the chief source of his revenues. Thanks to his efforts, on
Nowy Świat Street, the main commercial thoroughfare in Warsaw, the road was laid out in timber blocks. He acquired a vast country estate near
Częstochowa, in an area known as
dominium żareckie or "Żarki domain", including the town of
Żarki, and villages like:
Jaroszów, Zawada, Leśniów, Przewodziszowice,
Jaworznik, Ciszówka,
Myszków,
Nowa Wieś and Warcianna. There he brought in modern agricultural techniques in raising crops and
animal husbandry. He also opened a factory to produce agricultural machinery. He was also an active investor and financier. Among his roles were consultant to
Bank Polski, where he worked closely with
Henryk Łubieński, and was a senior consultant to the
Warsaw Stock Exchange. The registered office of his business was in the Mniszchów Palace in Warsaw, that had been refurbished for the Warsaw
Chamber of commerce (Warszawska Resursa Kupiecka), of which Steinkeller was an active member. However, not all of Steinkeller's initiatives were crowned with success. This was due largely to problems of a technical nature. Faith in foreign specialists was sometimes misplaced. Examples of this were his over-reliance on them in the restoration of
lead mines in
Olkusz, or in the production of
Farm equipment, or importing river barges from England whose draught was inappropriate for Polish waterways. His own financial situation took a turn for the worse towards the end of the 1840s. His indebtedness to Bank Polski, a new management (Łubieński and president Lubowidzki had been removed on charges of
malfeasance) at the bank and a fire at his Solec works led to his being declared bankrupt in 1849. All his assets in Congress Poland were taken over by Bank Polski. He returned "over the border" to Kraków, where he still owned assets like his brickworks and a roof-tile factory in
Podgórze. Not long after he died of a cardiac arrest. ==Personal life==