An archaeobotanical exploration of poo

Karen Stewart
23.08.2015

Senior Archaeobotanist Karen Stewart takes us through the wonderful and informative world of archaeological poo.

Archaeobotany can often be seen as one of the less glamorous strands of archaeology. Unlike artefacts, which can be viewed as soon as they emerge from the ground, it sometimes takes months, or even years, to get results from environmental sampling. Even so, I think environmental archaeology can tell us just as much about people’s daily lives as fragments of pot or metalwork.  One aspect that can provide us with an immediate link to people in the past is the archaeology of food.  When you discover remains that are similar to what you eat, there’s an immediate connection to the people in the past who were consuming them.

Which leads me to my favourite part of archaeobotany – poo. Digging in London’s urban environment means we frequently come across human and animal waste. Often this material is found in pits dug specifically for the purpose – cess pits. Finding environmental remains in these conditions commonly means you can really tell that you’re looking at food. Unfortunately, our collections are normally biased towards plants that have survived the digestion process, or were discarded before they could get that far.

So we get lots of fruits seeds, particularly things like cherries, sloes, figs and grapes, as they all have very tough seeds. We also get lots of bran – the tough outer layer of cereal grains, and spices, particularly coriander and celery, but also things like pepper, allspice and chilli in later periods. Studying these waste deposits, we can see the changes in tastes over time, owing both to changing trade and cultural preferences. They sometimes also reflect social status, with higher status indicated by more diverse and exotic remains.

Cess pits are often really good places to find nice artefacts too, as generally speaking, once people drop stuff down there, they’re not going back in to get them out! By the late medieval period, cess pits were just a temporary stop for human waste. A profession known as ‘gong farmers’ or ‘night soil men’ emerged, who would empty cess pits overnight while the city slept. It would generally take a full night for a team of night men to empty one cess pit. Given the time and labour involved, emptying a cess pit was an expensive process, and this may explain why they were often simply covered over and another one dug nearby. People would regularly tip lots of rubbish down the pits before they were covered over, all adding up to lots of goodies for archaeologists to sift through today!

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  • Post-medieval
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  • Excavation
  • From the experts
  • Artefacts

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