Wednesday, 24 September 2014

Recreating early medieval oat biscuits: experimental archaeology

Cooking oat biscuits at the edge of the fire

Experimental archaeology can help us understand how people carried out daily tasks in the past, revealing potential processes and social interactions involved in various activities. It’s a very useful, hands-on way for students to gain new insights into past societies. At the beginning of this month, I spent a very enjoyable day teaching undergraduate students about ancient crops and foods as part of the UCD School of Archaeology module “Experimental Archaeology and Ancient Technologies”. We are very lucky at UCD to have an on-campus area to undertake our experimental activities, the UCD Centre for Experimental Archaeology and Ancient Technologies. We can re-construct houses, build pottery kilns, undertake metalworking and many other tasks, all on campus!
As part of the “Experimental Archaeology and Ancient Technologies” module, we spent a full day with students on food-related activities. We processed crops from sheaf to grain using very basic implements, ground the grain into flour using saddle and rotary quern stones, and made a variety of stews and other food products.
One of our activities was the production of oat biscuits. We were inspired by the extraordinary find from Mick Monk and his team excavating Lisleagh ringfort (early medieval enclosed settlement) in Co. Cork (McLaren et al. 2004). They unearthed the charred remains of an oat biscuit, which was analysed by archaeo-chemist Frances McLaren. She found that the biscuit remains consisted of oatmeal and a low-fat dairy product, perhaps whey. The inclusion of whey would have produced a low-fat biscuit that could have been stored for a relatively long period. Whey is the liquid remaining after milk has been curdled and strained to produce curds for cheese.
Curds (left), whey (centre) and oat dough for biscuits (right)
First of all, we used the quern stones to grind oat grains into flour. The oat grains were kindly donated by Flahavan’s oat mill in Co. Waterford. We then needed to add a little whey to the oat flour. The traditional method of converting fresh milk to curds and whey is to leave the milk out for a few days. We used the method of heating the milk and adding an acidic substance (e.g. vinegar).
After separating the curds from the whey (using a muslin cloth), we added a little whey to the oat flour to make a wet dough. We took golf-ball sized lumps of the dough and flattened them out with our hands into the shape of oat biscuits. We then cooked the biscuits on a griddle at the edge of a fire for around half an hour. We learnt just how much time is required for non-mechanised food production, which has important implications for understanding how past societies structured their days. We also appreciated that tasty foods can easily be produced using basic ingredients and simple tools.
McLaren F, Monk MA, Sexton R (2004) ‘Burning the biscuit’: evidence from the Lisleagh excavations reveals new secrets twenty years on! Archaeology Ireland 18:18-20.