Thu, 03 Jan 2019
Sure we all love barbecued food, but wood-fired oven cooking is a whole new level of backyard deliciousness. For a lot of the work you could solicit the help of the family, with the promise of delicious cheesy goodness forever more. Hopefully, you'll get the job completed over a weekend if the weather’s fine.
First, decide where to site your oven. Unlike a barbecue, you can’t move a pizza oven around the back yard once it’s built. Choose an area with plenty of space around it – somewhere in full sunlight is good, so as to keep the oven as dry as possible. Though this design is well insulated with the various layers, please keep children and pets away while the oven is in use.
It is imperative that your plinth is strong enough to hold the oven, so please don't cut corners.
It should be dry in a couple of days but we suggest a week's drying time before using the oven for cooking.
This blog post is intended as inspiration and a general guide, please seek advice from a professional if you have no prior building experience.
What you’ll need…
For the oven floor:
About 30 bricks, at least 20 of them will need to be smooth and solid, with no holes or broken edges. Fire bricks are highly advisable, to resist cracking.
For the plinth frame:
20 concrete blocks and 5kg cement or 20 120cm x 20cm x 20cm wooden beams, an electric drill and long wood screws
Rubble and big stones (to fill the plinth)
10-14 bags of builder’s sand (20kg each)
125-175kg clay (the cheapest will do)
Assorted glass bottles
Chimney or plant pot (optional)
Large bag (14 litres or 6kg) of wood shavings, dry pine needles or straw
Tools and Basics:
Large heavy-duty plastic or tarpaulin sheet
Plenty of water
Old kitchen knife
Heavy duty gloves
10 litre builder’s plastic bucket
Lots of newspaper
Gumboots (for the puddling)
Essential technique: puddling
Mixing the clay and sand is the hardest, most time-consuming part of the building process. It’s best to mix this in batches as and when you need it.
For the first layer (step 3) you’ll need about three buckets of clay to six 10 litre buckets of sand. The final shell (step 7) will need four buckets of clay to eight of sand (1:2 ratio clay:sand).
You do the mixing (puddling) with your feet. Tip the sand onto a large tarpaulin, break the clay into thumb-size pieces and tread the two together with a little water. Hence the term 'puddling'. The mixture is ready when a tennis ball-size piece dropped from shoulder height holds together. If it splats, the mix is too wet; if it cracks, it’s too dry.
Step 1 Make the Plinth
This is the foundation of your oven, so it needs to be super solid. You can build the plinth frame out of bricks, concrete blocks or wooden sleepers. Clear the ground and dig a shallow trench 120cm x 120cm square. If you build the frame from bricks, or concrete blocks, use cement. If you’re using wood, screw the pieces together. You’re after a solid, square box approximately 1m high and 120cm square.
Fill with rubble and stones in the centre, then add a layer of sand and glass bottles. Keep the bottles whole and use enough to create a single layer. These will act as a heat sink, warming up, then radiating heat back up through the oven. Finally, top with a layer of smooth, solid bricks to form the oven floor. Bear in mind this is the surface you’ll cook on, so the bricks need to fit snugly together.
Step 2: Make the dome mould Takes about 1 hour
Make a mound of damp sand to form the clay around. You’ll need about 120kg sand. Centre it on the plinth you’ve already built and gradually construct the dome up like a giant sand castle. It needs to be 80cm in diameter at the bottom and 40-45cm high. Keep checking on it from above to make sure it’s round. When it’s finished, cover with wet newspaper to stop it drying out while you puddle the clay (see photo). You can make a template from cardboard to keep the whole round even.
Step 3: The first oven layer Takes about 2 hours, plus 4 hours drying
Roll handfuls of the puddled clay/sand mix into 20cm long, 10cm thick sausage shapes, then build them up in circles around the sand dome, starting from the base (leave the newspaper on), until the dome is completely covered. Work the clay lengths into each other, then smooth the outside with your hands. The layer should be about 7-10cm thick. Leave the clay to dry for 4 hours.
Step 4: Cut the entrance Takes about 1 hour
Using a kitchen knife, cut out the entrance to your oven. It needs to be big enough to fit a roasting tray through it, but small enough to keep the heat in – about 30cm wide by 20cm high. Once you’ve cut the entrance, scoop out the sand inside (you can reuse it). Let the dome dry overnight. The next morning, light a small fire inside to help dry out the clay further.
Step 5: Build the brick opening Takes 2-3 hours
Build an arch to fit around the entrance using bricks and more sand/clay mix as mortar. Secure the arch to the clay dome with more clay mix. Next, cut a hole in the roof of the dome near where the arch joins the dome and build a clay collar to hold the chimney. You can use a plant pot as a chimney, buy one, or build up rings of clay to make one (as in the photo).
Step 6: The insulation layer Takes about 1 hour, plus 2 hours drying
Make 4 litres of slip (a mixture of clay and water with the consistency of cream). Stir in the wood shavings, pine needles or straw (chopped into pieces) until well mixed. Slap the insulation layer onto the clay dome, then leave to dry for 2 hours.
How to use your pizza oven
Dried hardwood is best for cooking. Start with a pile of newspaper and small sticks of kindling in the entrance under the chimney. Slowly build the fire by adding pieces of hardwood and once it’s going, carefully move it towards the back of the oven. Once it’s roaring, add just enough wood to keep it ticking over.
Home made dough is the only way to go here. It’s cheap, it’s simple to make and with its low food miles and lack of packaging, you’re doing the environment a favour too! Here’s one recipe for starters:
This recipe makes enough dough for 3-5 of 12″ to 16″ (305mm to 406mm) thin bases for pizzas.
410 grams plain fine flour
7 grams active dry yeast – or one ½ tablespoon
1 teaspoon salt
250 ml “tepid” water
1. Mix all of the dry ingredients first, then add the water. It will appear to be too dry at first. Do not add water. Keep working the dough until it is smooth.
2. Let the dough rise once (1 hour). Punch it down and knead again.
3. Let the dough rise a second time for 1 hour.
4. After it has risen, punch it down and use it for your pizza. The dough will rise a little while you put your pizza toppings on it. First place the rolled out dough onto floured wooden paddle. Then place your toppings. Always start with tomato sauce, then mushrooms, then the rest of the ingredients and finish with cheese and olives. Slide the pizza inside the oven with the paddle, let bake for 2 minutes (turn around halfway through) and take it out. Cut and serve. Bellissimo!