NOVELTY - The method involves recovering a portion of hydrogen and carbon dioxide from bioreactor (22). A portion of first liquid effluent is introduced into gravity settler for separating a portion of first liquid effluent into first biomass including a portion of microorganisms and a second liquid effluent including a portion of volatile fatty acids, alcohols and microorganisms. A recovered biomass is provided by recovering a portion of first biomass and second biomass and introducing the recovered biomass into biomethanator (40) for production of methane and carbon dioxide.    USE - Method for producing hydrogen, methane, volatile fatty acids, and alcohols from organic material.    ADVANTAGE - Hydrogen, methane, volatile fatty acids, and alcohols can be recovered effectively from the organic material.    DETAILED DESCRIPTION - A portion of the first biomass is provided into the completely mixed bioreactor to maintain a concentration of microorganisms in the completely mixed bioreactor at a preselected value. The pH of the completely mixed bioreactor, the biomethanator, or both is controlled. The pH is controlled by adding pH adjustment compounds to the completely mixed bioreactor, the biomethanator, or both. The pH of the completely mixed bioreactor is maintained within a range of 3-6.8. A temperature of the completely mixed bioreactor, the biomethanator, or both is maintained. The temperature of the completely mixed bioreactor is maintained at a temperature range from about 25-37 degrees centigrade. The temperature of the biomethanator is maintained in a temperature range from about 25-37 degrees centigrade. The microorganisms include one or more of the species selected from the group consisting of Clostridium species such as C. butyricum, C. beijerinckii, C. acetobutyricum and C. bifermentants, enterobacter species, such as enterobacter aerogenes, bacillus species such as megaterium, thuringiensis, and R. sphaeroides. The completely mixed bioreactor is a reactor selected from the group consisting of a single continuously stirred tank reactor, a multi-stage continuously stirred tank reactor, an up-flow anaerobic sludge blanket reactor, an expanded bed granular sludge blanket reactor, a down-flow anaerobic granular media reactor, an up-flow anaerobic granular media reactor, an anaerobic baffled tank reactor, an anaerobic migrating blanket reactor, and an anaerobic fluidized bed bioreactor. An INDEPENDENT CLAIM is included for a system for producing hydrogen, methane, volatile fatty acids, and alcohols from organic material.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a system for producing hydrogen, methane, volatile fatty acids, and alcohols from organic material.    Biohydrogenator (20)    Bioreactor (22)    Biomethanator (40)    First biomethanator vessel (42)    Second biomethanator vessel (44)