Masonry ovens

Often I am asked – what is it that is so special about masonry ovens?

When my interest in baking grew to an itching urge to find out all I could within a few years so that I could set up my own bakery, these ovens were always called “brick ovens” by the old bakers.  They were often made with simple house bricks, perhaps with firebrick placed around the furnace area and where the flame path gushed out into the chamber across the front of the crown.  The big bakers’ ovens had a twentieth century improvement – a remote furnace, placed in a front wall, and when I began baking they were more likely fired with oil or gas.  At that time, the 1970’s, those I came across were already survivors, some would have called them relics of the past.  But quite a few bakers still used them, more in the country towns than the cities, particularly if they were still in good condition.

But what intrigued me most when I was a newcomer to real baking was that the old bakers whose knowledge I was tapping about the craft, would be likely to say something like this to me: “well, young ‘un, now that you are finding out as much as you can about fermentation and the craft, I suppose you will also have to learn how to build a brick oven”.  When I had heard this several times I became aware that the old craftsmen would categorically pronounce the brick oven as the best of all types.  Then, of course, I did set out to learn how to build one, and my first was built in Victoria, Australia, and it was fired with wood.

Nowadays it is valid to call them “masonry” ovens because in a modern oven there is a likelihood that the firebrick type of refractory masonry will not come in the form of a brick, but in many differently molded shapes that all lock together to form an oven.

The reason why masonry ovens are so good, the king of ovens, is the masonry itself: fired clay.  As a medium for cooking, clay is far superior to metal.  For us laymen bakers it is hard to understand, because here we are delving into physics, involved with the science and the nature of heat rays as physical emanations.  The heat ray emanated from clay, pottery, brick has a different profile from metal.  Clay absorbs a high storage level of heat and then radiates it for a long time.  To apply this to a large oven, it has absorbed an immense amount of heat during the firing cycle, then it has the capability to radiate this powerful heat from a deep source in a manner different from metal. By comparison metal’s heat is shallow and harsh, more damaging. The heat from the deep walls and thick floor of the masonry oven is indeed powerful, but there is a gentleness about it compared with the brittle heat from metal.  Regarding the actual set up of ovens as baking chambers, the modern metal-cased oven has its temperature repeatedly altered by thermostatic control with surging heat and often uneven heat.  A solid masonry oven simply sits there losing its heat very steadily, entirely even throughout the chamber.  When it is gone, you re-fire.

Another interesting thing occurs inside a brick oven – provided it has a well-fitting door.  The bread bakes under a blanket of its own steam, making a crust that is excellent in texture and of course well caramelized in that heat.  In fact the crust is so well turned out that you may hesitate before you bothered going to the trouble and big job of fitting steam injection.

All brick ovens are fitted with thick floor tiles that are deeply penetrated by the heat.  As soon as the loaves are loaded, the physical expansion and upward spring of the bread is superb.  This phenomenon we call “oven spring” is the final accolade of a well handled fermentation.  The bread lifts upwards as the gases within it expand, gaining lightness for its bulk, and opening up knife slashes or inclusions on its crust in a dramatic or pleasing way.  The quality of the oven spring alone would lead some bakers to want a masonry oven.

It is important to talk about the method of firing.   With the world’s dwindling resources and green-house gases being constantly brought to our attention, we are challenged to think about various issues surrounding our choices concerning fuel.        Wood, being a renewable energy source, is surely a worthy way to fuel your business rather than maligned fossil fuel. Masonry ovens are just as good for baking in when fired by gas or even oil burners, but relying on these fossil fuels is not exactly forward thinking.  Why not go with wood?  The wood decision also means a  further gain, being the benefit that the bottom crust of both pizza and large loaves are enhanced by a subtle flavour trace of the wood ash left on the floor after firing.

There is a final consideration about one’s way of life and the choice to be a real craftsman.   Working with a masonry oven, particularly a wood-fired one, involves a more challenging and exciting day.   You are wrestling with a more organic beast than a conventional steel oven, hence there are more thrills and spills.   The work is simply more thrilling because you have many more judgments to make, things cannot be altered or controlled by a mere turn of a dial or push on a button.

Paul Merry,             Nov 6, 2011