Testing Flotation Recovery Rates

The poppy seed recovery test is a simple and inexpensive means of determining the effectiveness and consistency of any particular botanical flotation system. By adding a known number of charred poppy seeds (Papaver somniferum) to a sample before it is processed, archaeologists can check for loss, damage, and inter-sample contamination. Different systems, equipment, methods, and personnel tested since 1976 yield recovery rate percentages ranging from 6% to 98%. Such percentages provide a basis of comparison among widely differing flotation systems and enable the archaeologist to decide which flotation system to use under particular logistical constraints.