Abstract: An apparatus for fermenting liquids is composed of a rear member angularly disposed to the horizontal, two vertical side members attached to the rear member, and a front member angularly disposed to the horizontal attached to the vertical side members and the rear member at its base. The angular disposition between the rear member and the front member is no less than 20.degree. and no more than 140.degree.. The apparatus thus has a small horizontal cross-sectional area at its base and a large horizontal cross-sectional area at its top. An inlet for introducing liquids to be fermented is provided at the base and an outlet for removing fermented liquid is provided at the top of the apparatus. A top member may also be included. The inlet cooperates with the rear member, the two vertical side member, and the front member to create within the fermenting liquid two turbulent zones and a non-turbulent zone.