Abstract In the work reported here, baker’s yeast ( Saccharomyces cerevisiae ) was used as feed for the production of liquid biofuels in a continuous one-step process under hydrothermal conditions in the presence of excess hydrogen and K 2 CO 3 . The yeast conversion experiments were performed in an up-flow reactor under near-critical water conditions ( T 330–450 °C, p 20–32 MPa). The products consisted of three phases, an oil-like organic phase, a gaseous phase, and an aqueous phase. Higher concentrations of organic carbon in the process resulted in a higher product yield. The heating value of the organic phase was up to 38.6 MJ/kg. Liquefaction of yeast without any addition of K 2 CO 3 also resulted in liquid oil, but the quality and the yield of the oil product were lower. A reaction temperature of 400 °C was found to be optimal for the oil yield and quality.