A method of treating bio waste including the steps of (1) fermenting substantially raw biowaste in a pathogen reduction stage under anaerobic conditions for a predetermined period at a temperature in the mesophillic temperature range and (2) subsequently separating the solid and liquid phases to produce a fermented cake and fermented liquor. The fermented cake has at least 15% solids on dry basis and contains over 500 mg/L ammonia, over 1,000 mg/L total Volatile Fatty Acids (tVFA) and Escherichia coli less than 100,000 cfu per g dry solids. The fermented liquor contains over 10,000 mg/L COD, over 500 mg/L ammonia, over 1,000 mg/L tVFA and less than 5,000 mg/L of suspended solids.