Ancient bread recipes: Archaeometric data on charred findings

This study examines charred bread-like samples found in several archaeological sites across northern Italy and dating from the Early Bronze Age to the Early Middle Ages, some of which are included amongst the UNESCO World Heritage Sites. The aim is to investigate differences and homogeneities in bread production processes in different eras and cultures. Bread was a staple food in many ancient societies, but has rarely been found amongst the materials that survive in archaeological sites. When it is found, it is usually because the bread was charred by accidental combustion (falling into the oven during baking) or deliberate combustion (for ritual purposes). The literature on the issue is not abundant, but has been growing over the past decade. There is, therefore, room to propose new study methodologies at this time. We studied eight samples of charred bread-like products and we used optical and scanning electron microscopy to identify plant tissue remains attributable to cereal caryopses, partly modified by bread-making processes. Energy dispersive X-ray spectroscopy and, for the first time, infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) were also used to investigate the composition and preparation methods of the different types of bread-like products. In particular, FTIR-ATR analysis can give indications about the presence of starch, gluten and lignin in the sample under investigation and it can, therefore, be used as a screening to guide subsequent SEM analysis in the search for specific cereal residues in the dough. In some cases, the different techniques used also revealed the presence of minerals such as silicates and carbonates, probably due to grinding residues or poor sample cleaning. During SEM observations, phytoliths, diatoms and framboids were also found in some of the samples.