Unsung Heroes of Cahokian Cuisine: Materials and methods for maize nixtamalization in southwestern Illinois

People who rely on maize for significant portions of their diets must process it to improve its nutritional quality, or risk severe malnutrition. A common method historically employed throughout the Western Hemisphere consisted of soaking maize kernels in an alkaline solution created from wood ash or burned carbonate material (e.g., limestone or shell), a technique referred to as nixtamalization. Recent research on pottery and limestone recovered from the East St. Louis site (11S706) by the Illinois State Archaeological Survey (ISAS) during an Illinois Department of Transportation (IDOT) project has yielded intriguing new data indicating nixtamalization was also practiced in the American Bottom of present-day Illinois as Cahokia grew to prominence as the first and largest Indigenous city north of Mesoamerica (ca. 900–1100 CE). A pilot study was conducted employing portable X-ray fluorescence, analyses of morphological variability and depositional contexts of archaeological samples of stumpware, and experimental use of stumpware replicas. The results of this study indicate Cahokian Mississippians and their Terminal Late Woodland predecessors nixtamalized maize using such seemingly mundane materials as locally available limestone and crude pottery utensils known as stumpware.