A thermal extraction method, comprising: i) preparing a diterpenoid-containing biomass starting material comprising a species of the genus Taxus or Austrotaxus, wherein the biomass is reduced in size to an average diameter of less than 2 cm in its smallest dimension; ii) introducing the reduced size biomass starting material into a thermal extraction system comprising a contained vessel, a heat source, and at least one recovery unit; iii) heating the reduced size biomass starting material to a temperature of from 250 °C to 650 °C to form a taxane-containing vapor; iv) quenching the taxane-containing vapor with a quench liquid in a direct liquid contact condenser; and v) collecting a thermal extract comprising: a) paclitaxel; and b) 7-epi-taxol, wherein: a) the ratio of the concentration of 7-epi-taxol to the concentration of paclitaxel in the condensed thermal extract is approximately 10; b) the ratio of the concentration of 7-epi-taxol in the condensed thermal extract to the concentration of 7-epi-taxol in the starting material is at least 10; c) the total residence time of the biomass starting material in the thermal extraction system is in the range of 0.2 to 5 seconds, wherein the total residence time of the material in the thermal extraction system is measured as the time interval from the heating up of the starting material in the thermal extraction system to quenching. i) preparing a diterpenoid-containing biomass starting material comprising a species of the genus Taxus or Austrotaxus, wherein the biomass is reduced in size to an average diameter of less than 2 cm in its smallest dimension; ii) introducing the reduced size biomass starting material into a thermal extraction system comprising a contained vessel, a heat source, and at least one recovery unit; iii) heating the reduced size biomass starting material to a temperature of from 250 °C to 650 °C to form a taxane-containing vapor; iv) quenching the taxane-containing vapor with a quench liquid in a direct liquid contact condenser; and v) collecting a thermal extract comprising: a) paclitaxel; and b) 7-epi-taxol, wherein: a) the ratio of the concentration of 7-epi-taxol to the concentration of paclitaxel in the condensed thermal extract is approximately 10; b) the ratio of the concentration of 7-epi-taxol in the condensed thermal extract to the concentration of 7-epi-taxol in the starting material is at least 10; c) the total residence time of the biomass starting material in the thermal extraction system is in the range of 0.2 to 5 seconds, wherein the total residence time of the material in the thermal extraction system is measured as the time interval from the heating up of the starting material in the thermal extraction system to quenching. a) paclitaxel; and b) 7-epi-taxol, a) the ratio of the concentration of 7-epi-taxol to the concentration of paclitaxel in the condensed thermal extract is approximately 10; b) the ratio of the concentration of 7-epi-taxol in the condensed thermal extract to the concentration of 7-epi-taxol in the starting material is at least 10; c) the total residence time of the biomass starting material in the thermal extraction system is in the range of 0.2 to 5 seconds, wherein the total residence time of the material in the thermal extraction system is measured as the time interval from the heating up of the starting material in the thermal extraction system to quenching.