Clay test pit
29/01/25 We’ve now dug a little test pit and extracted five rubble sacks of our London Clay, so our local potter friends can process the clay, fire some test pieces and get more idea how well the clay will fire in the lower temperatures in a wood pit or barrel firing. Initial tests look great, we are very excited! We can’t wait to see the results! The clay is super sticky and malleable, all the kinds of thing that are great for pottery but bad for growing plants!
Clay was extracted from a depth of around 300mm. Topsoil and clinker were dug out and moved aside. Clay is very clean with little root growth or organic matter. Test pit was around 600mm+ in depth. Test pit half filled with water after a week or so as the seasonal water table is very high.
Initial test firing
05/02/2025 A small sample pinch pot was fired, this gave a good colour and really started getting us excited with the project, however it wasn’t much of a gauge to see how larger pieces will stand up to the violent firing process in a wood firing, a fast rise in temperature. To help prevent cracking in the firing, the next step is to add “grog” to the clay to help it survive the thermal shock from the rapid temperature change. To make grog, we will fire some flint (found on site naturally) in a kiln.
Roasting the Flint to 1000 degrees Celcius in a kiln to produce Calcinated Flint, which makes the flint easier to grind. The fired flint is crushed & ground in water in a grinding pan.
The next step after processing the clay is to sculpt the pots, and allow to dry. The initial test pieces will be fired in an electric kiln to establish the firing temperature prior to some barrel test firings to establish the method and size and type of wood to fuel the burn.
Processing the clay
26/02/25 We’re currently preparing a small batch of our clay, experimenting with various processing methods and additions to determine what will work best for our next test firing. This involves carefully testing each approach to see how the clay responds under different conditions. While it’s a time-consuming process, gathering these results will allow us to better understand the properties of the clay we have on site. This will help us refine our technique and improve the success rate in the wood-fired barrel kiln, ensuring better outcomes for future firings.
Summary
We are making significant progress in testing and refining our approach to working with our London Clay. From extracting and processing the clay to conducting initial firings, we’re gaining valuable insights into its behaviour and how it responds to different methods. By adding grog and conducting further tests, we aim to improve the clay’s performance in wood-fired barrel kilns, ensuring better results in future firings. This ongoing experimentation will ultimately help us fine-tune our process, leading to more successful and reliable pottery outcomes.
Working with ceramics onsite is a new experience for us and having a facility for firing pottery and ceramic items at MOP will be a fantastic opportunity to really engage with the creativity, geology and history of ceramics in North London.
Thank you to those individuals and groups that have reached out and registered interest in the upcoming workshops and the potters who have kindly taken the time to help process and offered to test fire our clay. There is a really amazing local community of creatives and we can’t wait to see the outcomes this spring and pave the way for more making and learning at Meadow Orchard.
If you’d like to be kept up to date please send us an email or click the link below.
Meadow Orchard Project 
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