In order to better understand the BGO-crucible interaction, the wetting of the molten BGO on Ir substrates has been studied by the sessile drop method at 1050 degrees C. It was found that the oxygen partial pressure in the surrounding atmosphere is an important parameter. For P-O2 > 0.1 mbar, full wetting is observed without any visible contact angle. X-ray diffraction analyses have shown that Bi2Ir2O7 is formed at the interface. For P-O2 < 0.1 mbar, a drop is observed with a contact angle of 70 degrees and no chemical reaction is detected. Attempts to grow BGO samples under low oxygen partial pressure resulted in ingot without sticking with the crucible.