Pyrogenic dissolved organic matter (pyDOM) is known to be an important biogeochemical constituent of aquatic ecosystems and the carbon cycle. While our knowledge of pyDOM’s production, composition, and photolability has been studied recently, we lack an understanding of potential microbial mineralization and transformation of pyDOM in the biogeosphere. Thus, leachates of oak charred at 400 and 650 °C, as well as their photodegraded counterparts, were incubated with a soil-extracted microbial consortium for up to 96 days. Over the incubation, significantly more carbon was biomineralized from the lower versus higher temperature char leachate (45% versus 37% lost, respectively). Further, the photodegraded leachates were biomineralized to significantly greater extents than their fresh non-photodegraded counterparts. Kinetic modeling identified the mineralizable pyDOC fractions to have half-lives of 9 to 13 days. Proton nuclear magnetic resonance spectroscopy indicated that the majority of this loss could be attributed to low molecular weight constituents of pyDOM (i.e., simple alcohols and acids). Further, quantification of benzenepolycarboxylic acid molecular markers indicated that condensed aromatic compounds in pyDOM were biomineralized to much less extents (4.4 and 10.1% decrease in yields of ΣBPCA-C over 66 days from Oak-400 and Oak-650 pyDOM, respectively), but most of this loss could be attributed to biomineralization of smaller condensed clusters (4 aromatic rings or less). These results highlight the contrasting bioavailability of different portions of pyDOM and the need to examine both to evaluate its role in aquatic heterotrophy and its environmental fate in the hydrogeosphere.