When deploying an SOFC system on a biogas plant, one of the main concerns is the management of sulfur impurities. Sorbent- or reactive beds are usually employed to reduce sulfur concentrations well below 1 ppm. However, during long term operations, there still exists a risk that hydrogen sulfide, dimethyl sulfide (DMS), or other organosulfur compounds leak through the cleaning unit and pre-reformer. It is shown through impedance spectroscopy that even low levels (< 1 ppm) of sulfides degrade the anode charge transfer resistance and deactivates the water gas shift reaction; this in itself acting as indicator for sulfur breakthrough. Deactivation mechanisms take place through adsorption steps which are therefore highly dependent upon the temperature. We show how temperature control can mitigate sulfur-induced degradation and/or help in the regeneration of deactivated anode material. H₂S and DMS were used as sulfur impurities which exhibit different interactions with the anode surface. Their specific deactivation mechanisms are discussed based on electroanalytical data and gas chromatography.