Experimental archaeology can help us understand the past, by reconstructing ‘things’ in the present that were made, used, and discarded by the people of the past. At the museum we have a clay oven, which looks a little like a modern pizza oven and were used during the Late Iron Age in Britain. We did an experiment to try and work out how to establish the temperature of the oven using our senses, and to work out how much wood might have been used by the people of the past and what sort of things can be done with the oven.
We started at 9am and set a small fire in the base of the oven. One of our apprentices, Will, weighed all of the wood as it was added, and attached various temperature sensors to both the outside and inside of the oven; as the temperature changed, Jess kept a written record of how the temperature had changed and how much wood had been added to the oven. It took exactly two hours to reach 250*c, and this fluctuated as the wind blew down the loch! Gusts of wind had a huge impact on the temperature, making it drop by up to 80*c! Once the oven had reached temperature, we cleaned out the oven, removing all the embers, and used a wet rag to wipe inside the oven. This prevented heat spots that would burn our carefully prepared bread. The temperature dropped to 160*c when we were doing this, but once we had put the bread in, put the door on, and sealed it with clay, the temperature jumped up to 260*c which is hot enough to make bread. The small chimney at the top of the oven was also sealed, to keep the heat contained within the wall of the oven. The first loaf was a bit hard, but then Jenny made a second loaf which was slightly wetter, and this baked really well. We did not reheat the oven again and it stayed at 164*c for the rest of the day (6 hours), which was quite surprising as we expected the temperature to drop, but this gave us the opportunity to try other methods of cooking.
Jenny had made a stew, which we decided to slow cook. We left it in the oven for 3 hours and it was very tasty, with the vegetables cooked perfectly. Jenny also suggested that herbs could be dried overnight in the oven, as well as clothes dried on the top of the oven. In total, we used 8kg wood to heat the oven in the morning, which provided heat for the entire day and possibly until the next morning. We discovered that we could read the temperature by holding our arm near to the oven until it became uncomfortable – at 10 seconds the oven is approx. 180*c, 20 seconds is 165*c and 25 seconds is approx. 135*c. This would be understood by the people of the past; we had to start the experiment using scientific equipment to discover what they knew intuitively and then use our senses, without the equipment, to get a sense of how the temperature might have been measured in the past.
Our experiment will need to be repeated, which we intend to do at different times during this year. Toby is working out the internal and external diameter of the oven, so we will be able to use this information to work out how much heat the oven retains over time. By doing such experimentation, it helps us understand how people might have made and used things in the past, and how this improves our storytelling and interpretation at the museum.