The present invention is directed to a gas scrubbing process for removing at least one odorous vaporous compound from a gas stream generated by a rendering process or at least reducing the concentration of that odorous vaporous compound. In one embodiment, a series of two gas/liquid contactors is used, each having a different liquid scrubbing solution, with one scrubbing solution controlled at an alkaline pH and the other scrubbing solution controlled at an acidic pH. In another embodiment, the pH of the respective scrubbing solutions in each of the two gas/liquid contactors is reversed.