Archaeologist had long argued that stone vats at the sight were evidence of occasional ceremonial beer consumption. Teasing answers from the stones there and other its is not a simple process. Researchers use sieves, fine mesh and buckets to wash and separate debris from archaeological sits. Tiny bits of organic material, such as seeds, charred wood and burnt food, float to the top while heavier dirt and rocks sink. The vast majority of what emerges amounts to the raw ingredients, the bits that never made it into the pot.