Impact of charring on cereal grain characteristics: linking prehistoric manuring practice to δ15N signatures in archaeobotanical material

► We conducted controlled charring experiments of naked barley, emmer and spelt. ► Charring influence on grain characteristics and isotopic composition was examined. ► δ15N in uncharred grains was similar across six different grain weight classes. ► Charring did not distort the manure-derived isotopic imprint on δ15N in grains. ► We found the archaeobotanical applicability of the isotope approach very promising.