Monday, 28 April 2014

Grinding of cereals using quern stones

Grinding flour on an ancient quern stone
As part of the “Archaeology of Food” module that I am currently teaching at UCD School of Archaeology, the class recently attempted to grind whole cereal grains into flour, using both ancient and modern saddle-shaped quern stones. Although it was quite a lengthy process, we were successful, producing a relatively fine flour from both wheat and oat grains.
 
What are saddle querns, and how are they used?
Saddle quern stones have been used for thousands of years as grinding implements (Connolly 1994; O’Sullivan and Downey 2006). A saddle quern consists of a large lower ‘bed-stone’ and an upper ‘rubber-stone’. The bed-stone should be wide enough to contain the rubber-stone and of sufficient length to allow the rubber-stone to be drawn backwards and forwards on it (Connolly 1994, 26).

The rubbing-stone is hand-manoeuvred on the bed-stone, moving it in a to-and-fro action to crush and grind the grain. Quern stones can be also used in activities beyond flour production, such as the crushing of grain for meal and ale, as well as crushing and reduction of other substances such as bone and metal ore.

Making flour
Under licence from the National Museum of Ireland, we began to grind our cereal grains on an ancient granite saddle quern stone from Spahill, Co. Carlow. The date of this saddle quern is uncertain, but there is considerable Bronze Age activity in the area that it was found, reflecting a period with which saddle querns are often associated. Although it had been many years since the ancient quern was used to grind grain, we found it to be a very effective tool in producing flour.

Making flour on a modern quern stone
We also began grinding cereal grains on a modern granite saddle quern, produced by UCD Archaeology MA student, John Murphy. It was fascinating to learn from John about the process involved in making a quern stone. John’s finished product was both impressive and effective.

Lessons learned
The flour we produced was quite gritty. Students could understand how the inclusion of such grit in a person’s diet would have had affected teeth, in terms of wear and attrition.

We also learned that the repetitive grinding action is hard work. Extensive use of querns puts pressure on hip and knee joints, for example, which may be detected in osteoarchaeological studies (human bone). 

Finally, we gained a better understanding of just how long it takes to make a bread product. Early documentary sources clearly demonstrate that bread was a staple food product in Ireland, at least from the early medieval period (Sexton 1998). In approximately 40 minutes, we made enough flour for perhaps a small bread bun! Our hands-on experiment at UCD School of Archaeology thereby helped us understand what was involved in the ‘daily grind’ of past societies, and the level of time and resources required in food production.

References
Connolly A (1994) Saddle querns in Ireland. Ulster Journal of Archaeology 57:26–36.

O’Sullivan M, Downey L (2006) Quern stones. Archaeology Ireland 20(2):22–25.

Sexton R (1998) Porridges, gruels and breads: the cereal foodstuffs of Early Medieval Ireland. In: MA Monk, J Sheehan (eds), Early Medieval Munster: archaeology, history and society. Cork, Cork University Press, pp 76–86.