22
© Simon Brookes 2010 http://clayoven.wordpress.com BUILDING A TRADITIONAL CLAY OVEN A STEP-BY-STEP GUIDE

Clay Oven Building Instructions Web

  • Upload
    mnbvcxz

  • View
    500

  • Download
    2

Embed Size (px)

Citation preview

Page 1: Clay Oven Building Instructions Web

© Simon Brookes 2010 – http://clayoven.wordpress.com

BUILDING A TRADITIONAL CLAY

OVEN

A STEP-BY-STEP GUIDE

Page 2: Clay Oven Building Instructions Web

2

TA B L E O F C O N T E N T S Building a clay oven – the basics............................................................................................... 3

What you will need - Materials and equipment ........................................................................................... 4 The build order ................................................................................................................................................. 4 How long will a clay oven last? ...................................................................................................................... 5

The plinth and brick oven floor ................................................................................................. 6 Materials for plinth construction ................................................................................................................... 6 Plinth foundation construction ...................................................................................................................... 6 Plinth construction .......................................................................................................................................... 6 Brick oven floor construction ........................................................................................................................ 7

The clay-sand mixture and puddling technique ....................................................................... 9 Mixing or puddling ........................................................................................................................................ 10

The dome sand-former and first (oven) layer .......................................................................... 12 Sand former covered with newspaper ........................................................................................................ 12 The first (oven) layer ..................................................................................................................................... 12

The oven entrance and chimney ............................................................................................ 14 Cutting the entrance ...................................................................................................................................... 14 Drying the first layer – firing the oven ....................................................................................................... 14 Building the brick arch .................................................................................................................................. 15 The chimney ................................................................................................................................................... 16

The insulation layer ................................................................................................................ 17 The final layer ......................................................................................................................... 18 Firing the oven ......................................................................................................................... 19 The best pizza ever! ................................................................................................................ 20

The dough ....................................................................................................................................................... 20 Toppings .......................................................................................................................................................... 21 Other things you’ll need (ideally) ................................................................................................................. 21 Making the pizzas........................................................................................................................................... 21

Page 3: Clay Oven Building Instructions Web

3

BU I L D I N G A C L AY OV E N - T H E BA S I C S

I assume that most people will already know what a clay oven is, however it is probably useful if I define what I mean by a clay oven for the purpose of this guide. Before I do that though a quick word about nomenclature. I will use various names for the clay oven interchangeably; these include "clay oven", "traditional clay oven", "wood fired oven", "pizza oven" and "traditional bread oven". If you browse around the web you will also see the name "cob oven" being

used - cob being a mixture of clay and straw (+ or - sand). As I am not using straw in my build I will not use the term cob but will include it in my definition, as this type of construction is probably the most ancient of all clay ovens. Another name commonly used is earth oven. In my definition then, a clay oven is any hollow, dome-shaped structure constructed out of clay, clay and sand or clay and straw, used for the purpose of baking and roasting food. It has a brick floor and usually a chimney. Most traditional clay ovens are built outdoors and may or may not be covered with a simple roof structure. You will find some amazing examples of clay ovens, particularly huge pizza and bread ovens, built inside restaurants. The oven I have built is much smaller but still suitable for cooking for large groups of people. Clay ovens are amazing things. They look incredible and create a feature in any garden, large or small. The main reason most people want a clay oven of course is for cooking. If you have never eaten a pizza cooked at 350°C for 1 minute in a clay oven - you have never eaten a pizza! Just imagine a thin, crispy, slightly charred base covered in hot melted cheese, olive oil, garlic, sun-dried tomatoes, dried cured sausage, smoked ham, anchovies...do I need to continue? How about loaves of hot bread cooked to perfection, cracked open and smothered in real butter or a large joint of lamb or pork belly cooked slowly with herbs over night in the oven's residual heat, falling off the bone when you come to carve it the next day. OK enough of the M&S style adverts already! I think you get the picture. Cooking in a traditional clay oven is wonderful; it feels different and definitely tastes different. Building your own clay oven is not difficult. I am by no means an expert when it comes to DIY but am normally happy to give things a go. I have never built anything like this before but managed to complete my oven without any major disasters. The beauty of building a clay oven is that you use mostly natural and, if you are lucky, recycled or free materials. There is something very primeval about building one of these ovens. The process is a direct link back to our ancestors who would have used similar techniques for cooking many millennia ago. I thoroughly enjoyed building it! It is a very physical and tactile experience - you will handle and form every single piece of clay, sand and wood that goes into it and the finished product is something that you will be extremely proud of.

The Clay Oven in my Garden

The material for this guide is adapted from my original clay oven blog. On the blog you will find regular updates, video, more photos and also have the ability to post tips or questions to other blog readers. You can find the blog at the following web address - http://clayoven.wordpress.com

Page 4: Clay Oven Building Instructions Web

4

WHAT YOU WILL NEED - MATERIALS AND EQUIPM ENT

OK lets crack on with getting this baby built! Here I will list most of the equipment and materials you are going to need to build your own clay oven. I will provide details such as quantities later on as I step through the build process.

MATERIALS

Builders sand

Clay

Water

Rubble / hardcore

Wood shavings

Normal building bricks (e.g. London Bricks) for oven base

Large wooden "beams" or bricks or stone for plinth (I used beams as you will see later)

Cement if you are building plinth out of brick

Right-angled brackets and screws if constructing plinth from wood

Glass bottles (optional)

Old Newspapers

Plastic rubble sacks

Wood for burning in the oven

EQUIPMENT

Saw (chainsaw?)

Wheelbarrow

Bucket

Tarpaulin or thick plastic sheeting

Shovel

Spirit level

Large knife

Hands and feet!

Wellington boots or other sturdy boots

THE BUILD ORDER

So you have your equipment and materials list. Next I thought it would be useful to outline the order of construction. This will also form the basis for the rest of the sections in this guide, each section providing details for each stage in the build process. Simple - I hope! As you might have guessed already, I love a good list so here goes another:

1. The plinth foundation, plinth and brick oven floor 2. The clay-sand mixture and puddling technique

Page 5: Clay Oven Building Instructions Web

5

3. The dome sand-former and first layer or the oven layer 4. The oven entrance and chimney 5. The wood shavings and clay slip layer or the insulation layer 6. The final clay-sand layer 7. Firing the clay oven 8. Cooking in the clay oven 9. How Long Does it Take to Build a Clay Oven?

Construction involves quite a few steps and each step takes variable amounts of time to complete. Probably one of the most time consuming processes is puddling the clay-sand mixture (mixing with your feet!). One batch (two buckets of sand to one bucket of clay) will take about an hour to an hour and a half depending on the consistency of the component parts. If you get a group of people to help then obviously you can speed the process up. Many feet make light work of puddling! Building the oven layers is also very time consuming and you need to leave drying time between each layer if possible. The other major factor which affects the length of time it takes to build your oven is the weather. You can't construct anything other than the plinth if it is raining and it does tend to rain quite regularly in the UK! What with interruptions (both weather and non-weather related) from start to finish my oven took 6 weeks to build on my own. However if you have a spell of good weather and a few helping hands (and feet) I think you could build one in a week.

HOW LONG WILL A CLAY OVEN LAST?

To be totally honest I have no idea how long it will last. My original garden oven is now two years old and still going strong (with some care and maintenance!). The good people at River Cottage HQ suggest a couple of years but obviously this will vary dependent on your location, local temperatures, weather conditions, air moisture content, the type of cover or shelter your oven is housed in, the amount of use your oven gets, the type of clay you use for construction and many other factors. They are pretty robust but they are organic structures and they do crack after repeated heating and cooling. This is not a problem if cracking only affects the outer layer - you can fill the cracks with spare clay-sand mixture. However, once you get cracks in the internal oven layer then the oven's days are numbered. I say, don't worry too much, enjoy it and use it and if it falls apart you can build another one! Simon Brookes - June 2010

Page 6: Clay Oven Building Instructions Web

6

T H E P L I N T H A N D B R I C K OV E N F L O O R

Your plinth has two main functions. Firstly, it raises your oven to a height that makes it practical to use. Imagine trying to slide pizzas in and out of the oven on a baker's peel if the entrance is at ankle level. You would end up with a bad back and a charred mess in the oven! Secondly the top of the plinth forms the all important brick base to your oven.

MATERIALS FOR PLINTH CONSTRUCTION

Your choice of materials is dependent on personal taste, availability and budget. If you scour around the Internet you will find plinths made from natural stone, bricks, cob, wood and earth and wood alone (like mine). No one solution is better than the other so take your pick. I am going to show you how to build a simple but beautiful plinth made from wood. I was lucky enough to get hold of some oak beam off-cuts from a local timber merchant. They are very attractive and very heavy!

PLINTH FOUNDATION CO NSTRUCTION

If you are going to use a construction material with substantial weight from which to build your plinth and are building on soft ground you will need to establish a foundation first. This is pretty easy. In my case I dug a 40-50 cm deep hole slightly wider and longer than my intended plinth dimensions (120 cm x 120 cm) and filled it with hardcore (rubble) to a level just below the top of the hole. I then topped this off with a layer of builders sand and finally laid a paving top onto the sand. In pursuing the spirit of sustainability, I managed to get hold of some broken slabs which I laid as crazy paving to form the flat level of my plinth foundation. You can of course use other foundation methods such as concrete. If you are lucky enough to have a chosen a location with a solid floor on which to build your oven then you can skip this step.

PLINTH CONSTRUCTION

So you have a nice flat and solid base it is time to start building the plinth. This is where building with timber comes into its own because it is just so simple! Before you start building though you need to think about dimensions and this will involve a little forward planning.

PLINTH DIMENSIONS

The plinth needs to be wide enough (and as your oven is going to be circular I suggest you make the plinth square) to accommodate all three layers of your oven. The most important measurement is the diameter of the first layer - the inside of your oven. You need to decide what is practical for your needs. If you only ever intend to bake pizzas in it then it could be quite small but if you want to use it to roast legs of lamb or pork joints you need to make the oven layer wide enough in diameter to accommodate a roasting tin. The internal diameter of my oven layer is 80cm which therefore means the brick floor on the top of my plinth is also 80cm x 80cm (you wouldn't want any part of the wooden walls to be inside the oven when you fire it!). Working out from here, each of the 3 layers should be approximately 7cm thick, so the total thickness of the oven walls will be around 21cm.

Page 7: Clay Oven Building Instructions Web

7

Add this dimension to each side of your brick floor width and you will end up with the correct dimensions for your plinth. Phew! So my plinth top dimensions are 120cm x 120cm. Once you have your dimensions sorted, construction of the plinth is very easy. Simply cut the timbers to the correct length, not forgetting to leave enough space for the overlapping end of each side. Then build the sides up as if building a wall - overlapping the lengths of wood to add strength to the structure. You shouldn't need to use any "cement" between layers if you are using heavy timbers like mine. Try to make the top layer as level as possible as this will help when trying to level the brick oven floor. I used four internal corner angle brackets on each layer in order to prevent the structure from moving out of shape. Your next task is to fill the plinth "box" with rubble (hardcore) to a level of about 30-40 cm below the top. After this stage I decided to add a layer of builders sand followed by a layer of glass bottles (whole with tops removed). My reason for doing this is that the glass bottles should provide an extra layer of insulation and retain heat below the brick floor of the oven. I have no idea if this actually works but I had loads of bottles lying around so thought I'd give it a whirl! Finally add another layer of sand up to a depth below the surface of exactly one brick deep.

BRICK OVEN FLOOR CON STRUCTION

This is the last stage in construction of your plinth. The brick floor is obviously a critical component of your oven so I suggest you take your time with this and do it right. You'll need some bricks, something to cut them with and some more builders sand. I used bog-standard London bricks and a hammer and bolster to cut the bricks (although I'm not very good at this and broke quite a few!). Use any bricks you can get your hands on but try and look for ones with a nice flat surface, without cracks and avoid any that look too porous. Bricks with hairline cracks will break when you come to cut them, or worse still, when they are fired in the oven later.

The plinth dimensions

Internal structure of the plinth

Page 8: Clay Oven Building Instructions Web

8

LAYING THE BRICK OVEN FLOOR.

All you need to do then is fill the top layer of your plinth with bricks. I chose to use a herringbone pattern which holds together nicely without cement. Remember to try and keep the oven floor as level as possible. Once you have laid all of the bricks in place brush handfuls of building sand into any gaps to prevent any further movement of the bricks. That's it! Your plinth is complete and ready for the next stage - building the oven!

Constructing the herring bone pattern floor The finished plinth and oven floor

Page 9: Clay Oven Building Instructions Web

9

T H E C L AY- S A N D M I X T U R E A N D P U D D L I N G T E C H N I QU E

So now the fun begins! Before I get on to detailed instructions of how to build the oven I want to provide some details on preparing the all important building material - the sand-clay mixture.

INGREDIENTS

Builders sand

Clay

Water (optional)

EQUIPMENT

Shovel

Bucket

Tarpaulin

Thick plastic bags

Wheelbarrow

Wellington or other sturdy boots

Legs!

You can buy builders sand from any building suppliers, some garden centres and DIY stores (e.g. B&Q). Either buy it in individual plastic bags or get a job-lot delivered - you will use quite a lot.

WHAT TYPE OF CLAY SH OULD I USE?

I have had quite a few questions about the type of clay to use. As far as I know you can use any type of clay you can get your hands on. I dug my clay from a local farmer's field here in Hampshire (clay overlying Upper Cretaceous chalk if you are geologically minded - maybe Paleogene?). The team at River Cottage get theirs from a pond on site, in Dorset (I think it is Blue Lias). If you can't find any clay locally you could always buy potters clay which would be wonderfully homogeneous i.e. free from large particulate matter (stones!). Which reminds me, try to get clay that does not contain too many stones - they are liable to form the focus of cracks in your oven if left in the mixture.

QUANTITIES

The ratio of clay to sand is 1:2 (one part clay to two parts sand). I used a bucket as a convenient measure and found that one bag of builders sand almost filled two buckets which was nice! I think it is wise to make-up just enough mixture (with a little bit extra) to complete one layer of your oven at a time. Why? Well if you make up a huge batch (enough to complete your oven) it could dry out before you get a chance to use it if you get delays between layers (if it rains for example). So how much do you need for one layer? This will vary depending on the size of your oven. For mine, if we define one "batch" as two buckets of sand mixed with one bucket of clay, the first (oven) layer took

Page 10: Clay Oven Building Instructions Web

10

three batches (6 sand to 3 clay). This left enough over to fill small cracks after drying and to begin building the chimney. The outer layer required more mixture because it is covered a larger surface area. I used four and a half batches for this layer.

MIXING OR PUDDLING

Mixing the clay and sand is by far the most tedious part of the whole build process. What you are trying to achieve is a well-mixed material with no pockets of unmixed sand or clay and the only way to do this seems to be by using your feet. The process is known as puddling and it goes like this:

1. Spread a tarpaulin out on a firm surface (double it over in case you get holes in it).

2. Tip two buckets of sand in a pile onto the tarpaulin and spread out a little.

3. Next, fill another bucket with clay. 4. Take a chunk of clay and break it into

small pieces (thumb sized) and distribute them over the surface of the sand (like throwing broken-up pieces of mozzarella onto a pizza base!). Take this opportunity to dispose of any stones or sticks you might find in the clay.

5. Wearing your boots, start to mix the sand using your feet (puddling). The best technique is to tread and twist. I recommend putting some music on and get into the groove! Seriously, you will look pretty daft doing this but you need to twist - Chubby Checker sty-lee! This is where a group of friends come in very handy. Many feet make light work of puddling sand and clay. It is great exercise though so keep reminding yourself how much good it is doing you when you start to get knackered and bored!

6. Keep mixing until the clay lumps have disappeared then add more clay chunks and get back to puddling.

7. Keep repeating this until the bucket of the clay is mixed into the sand. I found it takes somewhere between 45 minutes to 1 hour to mix one batch. One tip I discovered which speeds things up is make sure the sand is damp before you start mixing. It definitely helps the clay mix in better (essentially you are coating sand grains with clay and water helps break down the clay mineral bonds I assume?). Add some water before hand if you need to but dont go mad with it!

Comment from the blog I might be wrong, but, if the oven is roughly a spherical shape, then you could calculate the volume of the half sphere formed by the internal part of the oven (80cm), then calculate the volume of the half sphere formed when the first layer is laid (94cm), and subtract one from the other. Converting it to liters, you would have an approximate quantity. I did the math (correctly, I hope – I suck at math), and got the following results (please correct me if I’m wrong): First layer – 83 litres Second layer – 113 litres Third layer – 145 litres If you’ve got a 10-liter bucket, then my calculations are, at least, approximate. : )

Thiago (Brazil)

Clay chunks distributed onto sand ready for puddling

Page 11: Clay Oven Building Instructions Web

11

The last thing you need to do is check that the mixture is of the correct consistency i.e. not too wet and not too dry. You might be surprised at how sandy the mixture seems but this is how it is meant to be. The team at River Cottage HQ had a great method for testing the consistency though which I will share with you.

1. Grab a handful of mixture and form a ball about the size of a lime.

2. Hold your arm directly out in front of your body at shoulder height.

3. Drop the clay-sand ball onto hard ground in front of you.

The ball should hold together quite coherently. If it splats flat the mixture is too wet and you should add more sand to dry it out a little. If the ball breaks to pieces (explodes) it is too dry and you can add a little water. Simple! Once you are happy that your mixture is just right shovel it into a thick plastic bag to keep it moist while you mix the next batch. If you are ready to start building your first layer I recommend shoveling the final batch into a wheelbarrow for ease of use. Wheel it over to your plinth - it's time to start building your oven!

Sand - clay ball after drop test. It held together just right!

Page 12: Clay Oven Building Instructions Web

12

T H E D O M E S A N D - F O R M E R A N D F I R S T ( OV E N ) L A Y E R

Finally it is time to start building your oven. For this stage you'll need:

Builders sand

Old newspapers

Water

Tape measure or long steel ruler

Clay-sand mixture You are going to build a large sand dome - the former which supports the first clay-sand layer of your oven. I really enjoyed this part of the process mainly because it provided a practical justification for the hours I spent building sandcastles on the beach with my stepson Thom when he was a little lad (to be fair it was usually me who wanted to build the sandcastles!). Tip lots of sand onto the brick floor of your oven. I'm not sure how many bags I used but I remember being amazed at how much was needed to build up the dome to the required dimensions. Remember the outside of this dome will form the inside dimensions of your finished oven. The base (widest part) of my oven is the same dimensions as the length and width of the brick floor (80x80 cm). I decided to make the height of my oven approximately half that of the diameter (40-45cm). Build up the dome, molding and sculpting with your hands until it is the desired height and a nice shape. A top tip from Steve at River Cottage HQ is to keep checking the shape of the dome from above, so periodically stand on your plinth to get that birds-eye view! Once you are happy with the shape, firm-down the sand with your hands.

SAND FORMER COVERED WITH NEWSPAPER

Next you need to add a layer of wet newspaper. This makes removal of the sand from inside the cavity much easier later on. It is a little tricky to get the paper to stick but persevere and you'll crack it. That’s the dome complete. Now you are ready for your first oven layer.

THE FIRST (OVEN) LAY ER

If you are doing this alone make sure you leave three or four hours to build your first oven layer. I made the mistake of starting in the early evening and ended up finishing it at midnight wearing a head-torch! Take some of the clay-sand mixture from your wheelbarrow in cupped hands and form it into an elongated/rounded brick shape. Press this first "brick" against the base of the dome and compress

Sand dome partly covered with wet newspaper

Page 13: Clay Oven Building Instructions Web

13

it into place, with one hand holding it against the sand former while the other makes a "karate-chop" type movement (using a straight hand) against the "domeward" side of the brick. This creates a wedge-shaped "brick" (sloping towards the dome) which helps when adding layers above and also removes any air bubbles from the mixture which may subsequently expand and crack the oven. You are aiming for an oven layer that is approximately 7cm thick and the simplest way to keep check of this is to measure the bricks periodically against a marked stick or even a piece of straw. Add another "brick" next to the previous one and, using the same technique, mold it into the first. Repeat the process until you have laid "bricks" around the whole circumference of the dome. Begin laying "bricks" on top of this first layer and continue, round and round, up and up, until you have completely covered the sand dome former. Remember to keep checking the oven layer thickness as you go. Don't worry if you end up with some variation in thickness - as you build the oven layer up you might find that the base widens out a little from the weight of "bricks" above. Smooth and shape the oven layer into a neat, coherent shape and don't forget to check from above. That's it! Your first layer is complete. You need to leave it to dry for a few hours before you cut the hole for the oven entrance - which I'll discuss next.

First few "brick" layers.

The oven layer dome is complete

Page 14: Clay Oven Building Instructions Web

14

T H E OV E N E N T R A N C E A N D C H I M N E Y

You have completed your first layer and now you need to build a nice entrance at the front of it in order to get food in an out (unless you leave it as a dome shaped sculpture!). At this stage we will also be removing the sand former and build a chimney. You should have left the oven layer to dry for at least 4 hours before you attempt to cut the oven door but don't leave it so long that the clay-sand mixture dries too hard or you will find it tricky to cut.

CUTTING THE ENTRANCE

The dimensions of the entrance are dependant on the dimensions of your oven. Generally though, you don't want it so big that it effects the heat retaining potential of your oven nor too small so you can't get anything bigger than a tiny pizza through it. In the end I chose the width of my door based upon the width of a standard roasting tray and, as it happens, the width of the bakers peel I had bought. Don't worry too much about the height at the moment because you will probably adjust that later on once you have

fired it. Roughly mark the width and curve of your oven entrance and then, using nothing other than a carving knife, slowly cut it out. It will probably come away in large chunks - a very satisfying experience! This is the moment of truth! Get yourself a bucket and start to excavate the sand from within the oven layer. Don't forget to keep the sand for later clay-sand layers. Hopefully you will be able to excavate the sand until you reach the newspaper layer on the inside of your oven without the dome collapsing. Take it nice n slow but I'm sure you'll be absolutely fine. Remove as much newspaper as you can but don't worry too much because it'll burn off anyway the first time you fire the oven.

DRYING THE FIRST LAY ER – FIRING THE OVEN

Next you need to dry your oven layer. If you are lucky enough it will dry nicely over a few days in direct sunlight. However you should also fire the oven at least once to help the drying process but also to check the entrance is high enough to allow smoke to escape (see below). The method for firing the oven is quite simple but do bear in mind that at this stage the oven will be rather damp and does not have a chimney so you might find it takes a little bit of perseverance to get the fire going. This is how I do it:

The oven entrance removed revealing the internal sand former

Page 15: Clay Oven Building Instructions Web

15

1. Prepare some nice "pencils" of kindling.

2. Scrunch up five or six pages of newspaper into balls and form into a rough pyramid inside but near the entrance to your oven.

3. Build up kindling around the newspaper as if building a wigwam.

4. Light the paper and hopefully the kindling will soon ignite.

5. Watch the fire closely and keep slowly adding more and more kindling until it starts to burn well.

6. At this point, using a spade, metal rake or even a bakers peel, slowly push the fire back a little into the oven. Don't push it too far because it is likely to go out.

7. Add more wood and when it is burning fiercely move it back some more. Eventually you want the fire to be burning in the centre-back part of the oven.

A couple of tips here. Firstly, take it slowly. If you try to move things along too quickly you are likely to extinguish the fire. If it looks like it is going out, screw-up a few balls of newspaper and throw them in. This is usually enough to re-kindle the blaze. Secondly don't use large chunks of wood - smaller pieces burn better. At this point you can modify the height of the oven entrance if you need to. Look carefully at how the smoke is moving. If it is "pooling" inside the top of the oven you need to cut your entrance higher to allow the smoke to escape. As the oven dries it will steam and might produce a few cracks. Don't panic! Fill in any cracks with spare sand-clay mixture before you move on.

BUILDING THE BRICK ARCH

Now the oven layer is dry you can build the extension to the entrance. Extending the oven entrance with bricks not only looks nice but it also protects the entrance from knocks. Simply build a sand former in the newly cut arch of your oven, extending forwards about one brick length. Place a brick either side of the former on the top of the plinth using some of the sand-clay mix as mortar to hold them in place. Gradually build up the archway around the former using more of the

"mortar" mix between bricks. You might have to use quite a lot of "mortar" in order to produce the correct curve for the arch (as you

Kindling burning in the entrance to the oven.

Brick arch and chimney complete.

Page 16: Clay Oven Building Instructions Web

16

can see in my photographs below). The last brick should form the keystone of the arch. Leave the "mortar" to dry a little then remove the sand former. Hey presto - a perfect arch!

THE CHIMNEY

You need to cut a circular hole in the top of your oven just behind the brick arch entrance. I sketched a rough circle on the top with a pencil then drilled holes around the circumference in order to help with removal of the now solid "cement". Just tidy the edges up a little with a knife then build-up a small 20cm chimney around the hole using more sand-clay mixture. Finally, close any gaps between the brick arch, the oven entrance and the chimney using the remaining sand-clay mixture. Entrance and Chimney done! Leave it to dry before we move onto the next stage - the insulation layer.

The brick arch and chimney from the front.

Page 17: Clay Oven Building Instructions Web

17

T H E I N S U L AT I O N L AY E R

Entrance dry? Chimney dry? Great! Let's start building the next layer - the insulation layer. What you'll need:

Some clay

Some wood shavings

Some water

A bucket

A wheelbarrow

A spade

A power drill and plaster mixer (optional) First thing you are going to do is make a clay slip which is simply clay mixed with water. The simplest way to do this is to put some water in a bucket and slowly add chunks of clay, squashing, squeezing and mixing with your hands as you go. Alternatively you could add water to half a bucket of clay and leave it to soak for a couple of days. You could then squish-up the clay quite easily. You are aiming for a consistency similar to that of thin natural yogurt. I spent quite a long time making my slip until I discovered a short-cut method using a drill and plaster mixer. It works really well but is very messy! Chuck your clay and water in a large bucket (or large bin) and blitz it with the mixer. Job done! Next throw some wood shavings into a wheelbarrow. I bought a huge bag of wood shavings from a local pet shop and I still have three-quarters left (any takers?). Add some of the clay slip and mix well with a spade or get your hands dirty. The mixture should be wet enough to form "bricks" similar to those you made for the clay-sand layer. Build up the insulation layer using exactly the same technique as before. Simple! Leave it to dry and then you can move on to the last step in the build - woo hoo!

The insulation layer complete.

Page 18: Clay Oven Building Instructions Web

18

T H E F I N A L L AY E R

The last layer uses the exact same technique as the first layer so you should be an expert by now. Using the same proportions, mix a batch of sand and clay together applying the good old puddling technique described earlier. Again, the amount you need depends on the size of your oven but remember that this last layer will require more than the first layer due to the greater surface area you need to cover. You will also need some spare mix to extend the chimney (if like me you didn’t make it tall enough first time round!) and to keep for filling cracks. Make “bricks” as before and gradually build-up the final layer. After you have inserted the last brick, pull-up a chair, open a cold beer and sit back and admire your work. Well done, your oven is complete!

The final layer. The oven is complete!

Finished oven from the front.

Page 19: Clay Oven Building Instructions Web

19

F I R I N G T H E OV E N

I discussed the process of firing the oven earlier but I thought it warranted its own section because if you don’t get this right – you won’t be cooking anything! This is the way I do it.

1. Prepare a nice big pile of kindling 2. Roll some balls of newspaper and pile

them just inside the mouth of the oven in a cone shape

3. Pile kindling sticks around the newspaper like you are constructing a teepee

4. Light the newspaper and let the fire catch. Now at this stage I have a handy cheat that you might find useful. I have a weed burner which I bought a few years ago and never used and it is perfect for getting these fires going in the oven. It isn’t very eco-friendly through so I won’t encourage you to buy one but if you have one lying around and some spare gas then go for it!

5. Gradually keep adding kindling to the small fire until it builds to a nice little blaze. At this stage you can move it a little further back into the oven. I push the fire using a shovel or, and I find this works well, my bakers peel.

6. The process is then to gradually add more wood (gradually larger pieces) and when roaring, push it back more until the fire is blazing near the back of the oven. This might take about 60 to 90 mins. Be careful when you are pushing the fire backwards as it has a tendency to go out. If you find it has died back try adding some small pieces of kindling and blowing and/or some balls of newspaper.

7. In order to get the oven up to temperature (and I mean so that it is capable of retaining heat, without a fire burning in it for several hours) you need to keep the fire blazing for at least another hour. If you intend to cook with a small fire still burning (how I cook pizzas), the oven will be ready after about now. Check the temperature with your oven thermometer. It should be nearing 300 degrees centigrade (or more) if you want to cook pizzas.

8. If you intend to remove the embers and use the oven without a fire burning it’s a good idea to spread the glowing embers across the floor of your oven for 10 minutes before removal. I then scrape them out with the peel or shovel and dump them into a metal bucket to cool.

Finally a word of warning. If you have any sort of hair on the front of your head and want to keep it that way WEAR A HAT OR CAP when you fire your oven. You will need to keep looking into the oven and when it is throwing out 450-500 degrees Centigrade of heat you will singe your hair. You may not find this as hilarious as my wife did!

Burning Kindling in the oven entrance

Page 20: Clay Oven Building Instructions Web

20

T H E B E S T P I Z Z A E V E R !

I’m not exaggerating when I say that pizza cooked in a fiercely hot clay oven is the best you will ever taste. Why are they better than pizzas cooked in the gas or electric oven in your home? It’s all about the heat! The oven in your home will reach a maximum temperature of around 250° C. A clay oven, fired for a few hours, will reach temperatures well in excess of 400° C and it’s this furnace-like heat that turns a thin circle of dough, topped with oil, meats and cheese, into an absolute gourmet treat! Pizzas cooked in a clay oven take no longer than 2 minutes to cook. They have thin, crisp and slightly charred bases while the toppings remain delicious and full of flavour. Is your mouth watering yet? Mine is so let’s get on with the main thrust of this chapter which, if you haven’t guessed already, is about making pizzas in a clay oven. Firstly, if you want the best pizza ever you really need to buy the best ingredients you can get your hands on. Make sure you buy good quality flour, organic if possible. Dried yeast is perfectly adequate so don’t worry about trying to get hold of the fresh stuff. The toppings are crucial too so don’t scrimp and buy cheap ingredients – you don’t need masses, so splash out and treat yourself to quality. The following recipe is borrowed/copied from Dan Stevens, a chef from River Cottage HQ (Dan has recently written the River Cottage Bread Handbook which available in all good bookshops).

THE DOUGH

INGREDIENTS (THIS IS ENOUGH TO MAKE AT LEAST 15 SMALL PIZZAS)

250g strong white bread flour 250g plain flour 350ml warm water (room temperature) 5g dried yeast (10g of fresh) 10g fine salt A glug of olive oil Add all of the dry ingredients to a large mixing bowl and give it a quick mix. Next add the water and mix into a rough dough. Finally add the oil and squidge it well into the dough. Flour a surface and tip your dough out onto it – it’s time for kneading! You can use a electric mixer with a dough hook

Pizza cooking in the oven

Page 21: Clay Oven Building Instructions Web

21

to do this if you prefer but I like to get working on the dough with my hands – it just seems right somehow! You will find that this dough is quite wet (sticky) compared to traditional bread dough.

A TIP ABOUT KNEADING.

There are lots of methods you can use for kneading dough but I like to use this one (again thanks Dan at River Cottage). Hold the dough ball to the surface of your table with the tips of your left hand. Then with the heel of your right hand placed in front of the fingers of your left, push the dough forward, stretching it along the surface top then, in a fluid motion, pull the dough back towards your stationary left hand. Rotate the ball and repeat. I normally knead for about 10 minutes or so. Lightly oil a large bowl, put the dough into it, cover with cling film and leave to rise until it is double the original size. That’s it – dough done!

TOPPINGS

The choice of toppings is totally up to you but here are a few essentials as far as I am concerned:

A mixture of olive oil, crushed garlic and herbs is, for my money, a much better pizza base topping than the traditional tomato sauce. Just drizzle or paint it over the surface of the dough before you add the rest of your toppings – it’s delicious!

Grated cheese (mozzarella, Gruyere, Cheddar)

Chunks of other cheeses (buffalo mozzarella, blue cheese)

Mixed cured meats (spicy sausages like salami and chorizo chopped or sliced, chunks of good organic ham)

Roasted artichoke hearts

Fresh basil

I would have suggested anchovies to give that powerful salty, fishy blast but unfortunately anchovies stocks are in crisis due to over fishing so I no longer buy them – I suggest you do the same for the time being.

OTHER THINGS YOU’LL NEED (IDEALLY)

A rolling pin

A wooden chopping board

A bakers peel (pretty much essential)

A sharp knife

MAKING THE PIZZAS

One of the best things about making pizzas outside using your own clay oven is building your own pizza – rolling out the dough, selecting various topping mixes from pots of delicious, fresh ingredients, sliding it onto a peel and finally into the hot oven. It is enormously rewarding and great fun so I always get everything ready outside then let friends and family make-up their own pizzas as they go – trust me everyone loves it! The process is simple:

1. Make sure your oven is really hot. I normally fire mine for about 2 hours before cooking. Leave a fire burning at the rear of the oven and keep feeding this throughout the cooking

Page 22: Clay Oven Building Instructions Web

22

period with extra wood. Scrape clear the floor of your oven. I normally push any embers to the back of my oven using the upside down blade of my bakers peel.

2. Grab a small piece of dough and roll into a rough ball – about golf ball sized should do. I prefer to make smallish (maybe 7-8″ diameter) pizzas because they are much easier to handle in and out of the oven.

3. Flour your rolling surface and rolling pin well but don’t overdo it with flour. You need enough to stop it from sticking to the surface but too much and it burns on the base of the pizza once in the oven.

4. Roll the dough out into a very thin disc (mine often come out looking like strange “country” shapes but it doesn’t matter). Add more flour if it sticks. Critically you want to ensure the base is NOT sticking to the surface because you will have all sorts of problems getting it onto your peel once the toppings are on otherwise.

5. Paint or drizzle the base with the olive oil or traditional tomato topping. 6. Throw on your toppings. Hint: don’t pile too much on your pizzas because toppings have a

tendency to fly off when you slide the pizza from the peel into the oven! 7. Slide the pizza onto your bakers peel – I find if you lightly dust it with flour first, then lift

one edge of the pizza and with a quick, fluid movement pull it onto the peel. Practice makes perfect!

8. Next you need to slide the pizza from the peel onto the hot floor of your oven. Again you might not get this right the first few times but persist and you’ll have it cracked!. The technique you need to master is “yanking” the peel from underneath the pizza - very much like pulling a tablecloth from underneath a fully laid table without breaking the plates or spilling the drinks!

9. Let the pizza cook for about a minute – keeping a close eye on it. I normally then slide the peel underneath it, take it out of the oven and rotate it through 180° so that the side that was facing the open oven entrance is now facing the fire burning at the back of the oven and vice-versa. You might end up with a pizza burnt on one side if you fail to do this. Pop it back in for a little while longer until you are happy that it looks cooked.

10. Slide the pizza out of the oven onto the peel then transfer onto a wooden chopping board. Slice and serve.

11. Savor the best pizza ever and feel smug that you have created such a spectacular thing! 12. Repeat until you and your guests can’t move for eating pizza.

Good luck and happy eating!