This study aims to get a better understanding of the passing phenomena of a rising gas bubble passing through a liquid-liquid interface. This is done experimentally with a narrow column by capturing the rising gas bubble with high speed imaging. The light phase consists of silicone oil and the heavy phase
consists of water with different glycerine concentrations. The viscosity ratio of the liquids and the size of the bubbles were varied in the experiments. Experimental results show the effect of liquid viscosity and bubble size, represented as the Reynolds number, on the retention time at the interface. Moreover results show the shape of the bubble when moving through the phases and compares the experimental results with bubbles in infinite medium. The results also gave interesting insights into conditions where the bubble passing the interface was encapsulated by heavy liquid.