The anaerobic reactors of a flavorless jelly producing company; had a low efficiency in the treatment of their wastewater, with approximately 12% of COD removal. For this reason, it´s operation was evaluated, in a pilot scale reactor, using as inoculum, sludge from the wastewater treatment of a similar facility, with an average Specific Methanogenic Activity of 0.115 g COD/gSSV.d. We worked with an initial concentration of 35 kgSSV/m3 of the inoculum, an average organic load of 2.6843 kgCOD/m3d and wastewater with COD of 6797 mg/L and total nitrogen of 1213 mg/L. The feed flow was 0.264 L/h, in order to obtain an hydraulic retention time of 27.14 h, equal to the value of the reactor of the company. An average COD removal of 65.24% was achieved. The results showed sulphide concentrations of 461.4 mg/L and ammonium nitrogen of 1054.4 mg/L; that were not inhibitory.