Archaeological plant remains from excavations at Qasr Ibrim, Egypt, preserve volatile decay products trapped within internal networks of structural and storage macromolecules, These volatile components can be linked to specific degradative reactions occurring during the long-term burial of organic matter, Abundant alkyl pyrazines are characteristic by-products of the Maillard (or browning) reaction of proteins and carbohydrates and provide evidence for the reaction occurring in buried organic matter.