Dairies generate residues of which whey is the most important wastewater produced with extremely high organic content. Such a high organic-strength wastewater is particularly suitable for methane production via anaerobic digestion. The biological degradation of cheese whey is characterized by unstable operation. Supplementation of alkalinity is necessary during the start-up or high loading rate period. pH control system was created by using porous composite material (AM) with additional buffering capability up to few weeks. The porous structure provides slow alkali release system which is necessary in anaerobic fermentation processes with unstable pH to provide optimal conditions for the microorganisms. The addition of AM resulted in significant biochemical methane potential increase.