A few years ago, I wanted to build a small clay bake oven as a project for the Northern Lights A&S Competition. There are a couple different ways to do it; the one I went with was going to be portable (for obvious reasons). Gode Cookery has several good primary images of this sort of thing. This is the one with the best detail.
It’s a basic clay form, constructed over a wattle framework for support. All the accounts I’ve read say to expect the wattle to burn out in the first or second firing, but that the clay will hold its form after being fired. I took a lot of construction notes while I was at Plimoth. While theirs are massive stationary ovens, mine would be essentially a scaled down version.
I dug the clay from a bank in a river a few miles away. We could only get to it by boat, so Ekk held the boat steady while I dug and filled a number of five-gallon pails. Once home, I had knocked together a frame already. I tacked some expanded metal mesh into the base (for support, since I don’t think I trust the boards along the bottom edge) and put handfuls of leaves over it to keep the clay in while it dried. Ekk lent me a cart, which is for display purposes only.
The base was pure clay, laid over stacked high-insulating foundry bricks. The foundry bricks are kinda like a ceramic styrofoam and are very good at preventing heat transfer, which I hoped would keep my little borrowed cart from bursting into flames. I planned to add a little bit of chopped hay into the clay mixture for improved stability with the walls. A period technique is to use manure, which I’ve got no problem with, but I suspect if I do that nobody will want to touch it thanks to modern squeamishness. (Seriously, once the oven’s been fired to 500+ degrees, I really doubt anybody’d be catching anything even if there was anything to catch.) But all the old, sun-bleached horse manure we have around the yard is *just* the perfect consistency for chopped hay for this sort of use… Heh.
Any outdoor project is complicated by livestock. At my place at the time, I had horses and a large flock of free-range chickens. (We’ve since added a goat.) The horses can be especially destructive, particularly since they’re very friendly and like to “help” with whatever you’re doing. The chickens liked to perch on the cart and watch, occasionally jumping down into my work to peck at anything they thought looked tasty. The clay also bore the marks of our two cats, both of whom came over to investigate and left prints in the wet clay. (Much to their disgust.)
A number of things went wrong with this. For starters, I don’t have willow trees on the property, so I had to replace a number of the thin saplings I was using as they became brittle and snapped while being woven. When I did get all the main arches up and started weaving my “basket” frame, I discovered I’d placed the arches too close to the edge and would never be able to get enough clay mixture thick enough over the framework.
The realization I’d have to start all over again with the oven layout was pretty demoralizing. It was starting to get really cold, and I knew I only had a week or two left until things started freezing up. Working with wet mud in mid-30s Fahrenheit is not a fun project. At this point, I realized it’d be better to concentrate on my other projects and leave this one for another time.
As you can see by the leaves on the ground, it was late fall when I started this project, and I honestly should’ve known better. I was unable to finish the oven due to the onset of winter in Vermont, which froze the whole thing solid before it was finished. Northern Lights came and went (it’s a mid-winter event), and the clay base in its cart was slowly eaten by my chickens and horses. Yes, they’re weirdos.
I still hope to revisit this project and try again. A clay bake oven has been a goal of mine for years. I’ve always loved them, both from a period aesthetic view and the delicious pizzas you can make in them. Ultimately, I want to get a small portable oven I can take to long weekend SCA camping events just for the experience of making fresh hot bread in camp.