Years ago, I bought a small terracotta oven inner from the magnificent Trinity Court Potteries (http://www.trinitycourtpotteries.co.uk/) to make a portable oven to take to reenactments. For years it acted as a small roundabout in our living room , collecting fluff when finally a couple of weeks ago, I decided to act.
This is the story of my small oven and its journey towards baking bread.
The terracotta liner is a bit of a cheat as to my knowledge, no such pre-made inners existed in the middle ages however it is in essence, baked clay and so that in itself is not too much of a crime against authenticity. For true clay oven building techniques using sticks and daub there are many fine websites and instructional manuals out there that will tell you how to do so.
To set the portable oven up for baking you will need:
- A Trinity Court terracotta clay oven.
- A wooden board or trestle
- Some brass or copper wire
- A sack of browning plaster
- A few handfuls of straw, cut up short
- Two 2″x1″ blocks of wood, approximately 12″ long (optional)
- Lots of patience
First, you need a base for your oven. Most wood fired ovens have the luxury of a permanent home but the portable nature of this oven means that it needs a solid base to sit on, otherwise you may well end up weeping over the cracked remains of your deceased oven pretty quickly. I used an old trestle table from my reenactment kit but there are good instructions for making one (and more good tips for setting the oven up) here http://jpgsawyer.weebly.com/uploads/7/4/7/3/7473762/oven.pdf .
When I first set the oven on the trestle, I made the mistake of not putting any plaster beneath it and turned part of my table to charcoal, so don’t forget to sit it on a bed of plaster.
Here is how I set the oven up:
Decide where on the trestle your oven is going to go.
I decided to place my oven at the far end of the trestle, leaving the other end free for putting things on, proving dough and acting as a work surface. I then marked the position by drawing around the base with chalk.
Decide how you are going to fix the oven to the table.
I went for wiring it to the table with 2mm brass jewellery wire as the wire will be exposed to heat, moisture and a heavily alkaline environment due to the plaster and brass does not corrode as readily as ferrous metal. It was then decided that the best way to fix it to this particular trestle was to drill holes at 2, 10, 4 and 8 o’ clock points.
Mix the plaster and straw
Put 2 litres of water in a large container that you don’t mind being spoiled. Then slowly add browning plaster, stirring as you go until you have a consistency resembling soft margarine. When this consistency is reached, add the chopped up straw a handful at a time, stirring slowly with a stick as you go. Continue until there is an even spread of straw throughout the mixture. You should need no more than two handfuls of straw to achieve this. Don’t worry if you run out, you can always make more up should you need to.
Set the oven on its trestle and fix it in place
A bed of plaster and straw about 1cm thick was set down, then the two wooden blocks set down to give strength to the base. More plaster was set down to cover the blocks, giving a raised plaster base beneath the whole of the oven of about 1.5 inches thick. The wire was then wrapped around the chimney of the oven and through the drilled holes. It was then twisted up and over itself to secure the oven firmly to the base. There must be no movement of the oven whatsoever.
Plaster the top and sides
Continue plastering until the top and sides are covered in a layer of plaster at least an inch deep. Remember that you are relying on the plaster to not only protect your oven from rapid exchanges of heat but also to insulate it and keep heat in long enough for you to cook.
After this, leave the oven to dry naturally for approximately 7 days, patching any cracks as they appear with more plaster mix (minus straw).
Next step: Firing for the first time and cooking!