Previous studies in an atmospheric bubbling fluidized bed (BFB) gasification system indicated significant tar variability along the system. In this paper, the experimental procedure has been improved for reliable results and understanding of tar variability in the producer gas. By introducing a new sample point for tar analysis to the system, experiments indicated tar reduction in the gasifier, probably due to continuous accumulation of char and ash in the bed, as well as in the ceramic filter because of thermo- and catalytic effects. Thermogravimetric analysis of the filter sample indicated 14% of volatile inorganic compounds, and additional analysis of inorganic parts showed alkali and alkaline earth metal content, well-known as tar breakdown catalysts.