We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications provide for (1) a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation of state, (3) temperature, volume, and pressure measurements of low uncertainty suitable for equation-of-state development, (4) consistency with a century of historical data, (5) an assessment of the energy content of each distillate fraction, (6) trace chemical analysis of each distillate fraction, and (7) corrosivity assessment of each distillate fraction. The composition-explicit channel is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to the measurement of rocket propellant, gasolines, jet fuels, diesel fuels, and crude oils. In this paper, we present the application of the technique to representative batches of commercially available biodiesel fuels sold as B20 and B100. The distillation curve data that are presented are of sufficiently low uncertainty that they can be used for thermodynamic modeling of these complex fluids. Moreover, we present not only the distillation curves but also a chemical characterization of the 0.025, 10, 50, and 80% fractions and discuss the contrasts among the various mixtures.