Bed material coating in fluidized biomass combustion plants is a precursor for bed agglomeration. While bed agglomeration is a well-described problem in connection with biomass combustion plants, the literature on bed agglomeration or bed material coating in gasification plants is sparse, Recently developed biomass gasification plants face similar ash-related problems, but inorganic matter is also linked to their catalytic activity to reduce the tar concentration in the product gas. This paper summarizes recent ash-related research activities at a dual fluidized bed steam gasification plant located in Gussing, Austria. The used fuel is forestry residues; the bed material is olivine. The setup of inorganic flows and loops is described. Bed material analyses were carried out and presented, such as X-ray fluorescence, X-ray diffraction, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The analyses show the building of two calcium-rich layers around the bed particles. The inner layer is homogeneous, composed mainly of calcium and silicate, while the outer layer has a similar composition to the fly ash of the plant. Analyses of the crystal structure of the used bed material show the formation of calcium silicates that were not detected in the fresh bed material. This has consequences on the performance of the plant concerning the catalytic activity of the bed material and the tendency for fouling in the plant.