The invention relates to a process for producing organic acids, acid derivatives thereof and/or organic alcohols. In particular, the invention relates to a process for culturing a butyric acid-producing micro-organism in a culture vessel; transferring a portion of the butyric acid which is produced in the culture vessel to a separate compartment; and then reintroducing a portion of the acids from the second compartment in a controlled manner into the culture vessel. The invention also relates to a process for making butanol. The invention further relates to a process for culturing a butyrate-producing micro-organism in a first compartment of an electrochemical reactor, passing a direct current electric field across the electrochemical reactor and harvesting butyric acid or acid derivatives thereof in a second compartment of the reactor. The invention further relates to a process for producing butanol from the butyric acid.