Steam gasification of biomass to produce synthesis gas (CO, CO2, H2) was performed at high temperature (1273-1623 K) in an aerosol flow reactor. High temperatures and rapid heating lead to fast reaction kinetics, high conversion efficiencies, and very low tar production. The formation of syngas from biomass is a critical reaction in a promising method to produce liquid fuels from a renewable energy source. Current methods of gasification burn a portion of the biomass to provide the heat of reaction which decreases the quantity and quality of the syngas. Concentrated solar thermal energy offers a renewable alternative that can greatly increase the syngas quality and yield. Fundamental understanding of reaction parameters on conversion efficiency is needed to optimize the solar reactor design. An electrically heated aerosol reactor was constructed to investigate the effects of temperature, particle size, carrier gas flow rate, and steam addition on the carbon conversion efficiency in a controlled environment. Conversion efficiencies ranging from 6% to 88% were observed using corn stover at residence times on the order of 0.5 seconds with a particle size ranging from 150-2000 μm.