Mysterious vessels in sight: Archaeologists have discovered the purpose of characteristic bronze cauldrons that are often found in modern-day Mongolia. Protein analyses of the remains of the contents show that Mongolian nomads used them to collect blood from animals – probably to make sausages. Traces of yak milk were also found in the cauldrons, which are around 2,700 years old. This is the oldest archaeological evidence of the use of this special type of cattle in the Mongolian steppes, say the researchers.
The focus is on a region that at first seems remote, but whose inhabitants have repeatedly shaped history: the north-eastern steppes of Eurasia were home to peoples who early on harassed the Chinese Empire and built great empires. Later, the region in the area of present-day Mongolia also gave rise to the feared cavalry troops of Genghis Khan. This far-reaching significance makes research into the history of the Eurasian nomadic peoples particularly interesting.
As the research team led by Shevan Wilkin from the University of Basel reports, certain objects have often been discovered in the region that have so far remained a mystery. These are characteristically shaped metal kettles with handles that date from the Bronze Age or early Iron Age. In addition to the archaeological finds, rock drawings also testify to the importance of these vessels. They can be seen between images of the nomads’ huts. What exactly they were used for, however, remains unclear.
Remains of the content analyzed
To find out what was once the contents of these vessels, Wilkin and her colleagues have now examined two examples that were found in the north of what is now Mongolia. To determine their age, the team first carried out radiocarbon dating using samples of the leather material in which the bronze vessels were wrapped. They are therefore both around 2,700 years old and were therefore used by nomads in the region in the late Bronze Age. Inside, the researchers found incrustations that are obviously remnants of the former contents. They then subjected these traces to proteomics analysis methods. This allows proteins to be identified and assigned to specific origins based on their molecular characteristics.
As the researchers report, the remains of blood from ruminants such as sheep and goats were clearly detectable. “Various historical reports claim that the steppe inhabitants regularly drank blood,” says co-author Bryan Miller from the University of Michigan. However, the researchers do not see the finding as evidence of this alleged custom. They believe that the blood in the cauldrons was hardly intended for drinking, but rather for making long-lasting products from the animal blood. Blood sausages are still one of Mongolia’s typical culinary specialties today. To make them, the blood from slaughtered animals is collected in containers, mixed with other ingredients and then filled into intestines. “It is obvious that the processing of blood was already a traditional part of Mongolia’s food culture back then,” says Wilkin.
Milk from special farm animals
In addition to the blood proteins, the researchers also identified traces of milk in the vessels. What was special about this was that they were able to attribute the corresponding proteins not only to domestic cattle, but also to special farm animals: yaks. This robust type of cattle still plays an important role in Mongolian livestock farming today. However, it is unclear exactly when this tradition began there. “The finding now proves that yaks were domesticated and milked in Mongolia much earlier than previously thought,” says Wilkin.
But why are there traces of blood in the cauldrons, but also of milk? As the team explains, there are two possible explanations for this: In addition to processing blood, the cauldrons could also have been used occasionally to make yoghurt. Perhaps the milk was also used as an ingredient in sausage production.
Source: University of Basel, specialist article: Scientific Reports, doi:10.1038/s41598-024-60607-4