Deproteinized cheese whey is the residual of ricotta cheese production, widespread in the Mediterranean countries. Its popular name is “scotta”. The scotta disposal rises concern because of its high pollutant load. Its exploitation as a substrate for biogas production could obviate to this problem. The main component of the scotta volatile solids is lactose. Due to the high susceptibility of lactose to fermentation, using scotta alone in anaerobic digestion may lead to digestion blocks, because fermentation lowers the pH to levels which are prohibitive for the methanogenic populations We studied methane production using pig slurry in codigestion with scotta (70:30) and bioaugmented microbial consortia as inoculum in a laboratory, in-batch, experiment. Treatments were: pig slurry, single stage (LI_U); pig slurry + scotta, single stage (LI+S_U); pig slurry + scotta two-stage, using a bioaugmented microbial inoculum in the second stage (LI+S_D); pig slurry + scotta, two stage, without any re-inoculum in the second stage (LI+S_D_NRI). A very low amount of CH4 was obtained in the LI+S_U treatment, due to the rapid acidification of the substrate. At the end of the incubation period (72 d), the CH4 yield with LI+S_D was 50% higher than that with LI_U. The time to join the stationary phase of methane production was reduced by 34% in LI+S_D_NRI treatment, and by 68% in the LI+S_D. A great amount of H2 was produced at the start of the digestion period in LI+S_U and in the first stage of the two-stage treatments. At the end of the digestion period, volatile solids were reduced by 59%, 66%, and 65%, in the LI_U, LI+S_D_NRI, and LI+S_D treatments, respectively. Using pig slurry in codigestion with scotta permits to avoid blocks in anaerobic digestion thereby increasing methane production, reduces the digestion time, and gives also rise to the production of an appreciable amount of H2.