AbstractThe purpose of this work was to develop a two‐chamber bioelectrochemical cell to modify the metabolic activity of rumen microorganisms by applying an electric potential to the ruminal liquid. Carbohydrate fermentation changes were evaluated along with a molecular characterization by DNA sequencing of the ruminal microbial community. We observed that an electrochemical stimulation potential of 0.75 V enhanced basal acetate, propionate, and butyrate production by 71%, 86%, and 63%, respectively, with no detectable effects on grass substrate disappearance. The applied electric potential also led to changes in the volatile fatty acids production but not on the core microbiome.