The objective of this research was a feasibility study for biohydrogen production from raw brewery wastewater through dark fermentation by using the mixed culture originating from the brewery digested sludge. Heat, acid, base, chloroform, and freezing and thawing pretreatment methods were applied to suppress methane-producing archaea, which are hydrogen-utilizing microorganisms. A glucose-based substrate was used to acclimate the pretreated microorganisms. The acclimated mixed microorganisms were used as a parent culture. Digestion of brewery wastewater by the separate pretreated microorganisms was performed in semi-continuous and batch modes. The results indicated that raw brewery wastewater digested with the pretreated microorganisms under the tested conditions was not appropriate to produce hydrogen. Methane-producing archaea in brewery digested sludge were found to be stress-tolerant to temperature change and chemicals then could be recovered to produce methane effectively when sufficient time was allowed. Raw brewery wastewater and brewery digested sludge treated anaerobically were appropriate to produce methane rather than hydrogen. Copyright (c) 2015 John Wiley & Sons, Ltd.