Modern industrialization has resulted in an ever-increasing demand for petroleum-based fuel production and electricity generation. Exploitation of fossil fuel reserves have, however, raised grave environmental concerns due to rising carbon dioxide emissions in the atmosphere. While there is existing technology to generate electricity without having to combust coal or natural gas, there are severe engineering challenges at stake that hinder the production of a “carbon neutral” energy source capable of displacing petroleum-based fuels. One option to counter act the engineering challenges to some extent is the thermochemical conversion of lignocellulosic biomass to produce biofuels. Due to its vast abundance in the Earth’s surface, lignocellulosic biomass is a promising source of renewable energy source that is considered carbon neutral which can help dwindle the dependence on fossil fuels. Torrefaction/Pyrolysis of biomass is one thermochemical strategy with the ability to produce high yields of bio-oil; however, few unfavorable properties of bio-oils produced in such manner raise economic viability concerns due to the increasing costs associated with the upgrading/refining of the bio-oil and the resulting infrastructure required for such purification. In this contribution, we consider the effects of heritable traits achieved on the thermochemical product streams of mutant and wild type (i.e. unmodified) switchgrass samples. This study incorporates genetic modification to understand and examine the broad thermal stability of lignin. It is hypothesized that mutant switchgrass samples exhibiting low S/G ratio will result in lower phenolic yields at low temperature thermal treatments without altering the total lignin content present within the biomass. By changing various process conditions (temperature and time) and calculating the cumulative yield of phenolic products per milligram of the raw biomass upon torrefaction and pyrolysis, it was observed that the hypothesis held its ground. This approach helped develop a more thorough comprehension of which compositional features of the biomass are responsible for resulting thermochemical product distribution; such understanding will, in turn, allow catalytic valorization techniques to be customized for each specific product stream, thus making the process more economically viable.