While it is generally agreed that food processing has had a role in human evolution, the specific ways that is has affected our evolution are not well understood. Using a Niche Construction Theory (NCT) perspective, coupled with methodologies borrowed from “post-harvest” research in the plant sciences, this paper investigates the means and mechanism by which food processing is of evolutionary consequence. The central tenet of NCT is that organisms have an active role in their own evolution through reciprocal interactions with their environments; niche construction is understood to occur when organisms initiate long-term changes to their environments that modify the selection pressures on themselves and their descendants (and on other organisms in the environment). Humans and our hominin ancestors are considered to be the ultimate niche constructors due to our ability to modify selection pressures through diverse culturally generated and transmitted cultural means, i.e. cultural niche construction. In this paper, post-harvest methods are used to identify how food processing could feasibly have permitted hominins to modify their evolutionary selection pressures. Food processing is shown to facilitate access to increasing amounts of digestible nutrients and energy (kilocalories/kilojoules) as well as promoting increased dietary breadth and making possible the production of safer and more stable foods. It is argued that these advancements catalysed related technological and ecological skills and knowledge, which together with the nutritional benefits, further triggered changes in hominin brain and body and locomotory adaptations and increased longevity, disease prevention and juvenile survival rates.