Article Courtesy of Pizza Today Magazine    

  Not everyone can care for and feed a wood-burning oven. The wood structure, although fast-cooking and aesthetically pleasing, requires a good bit of training and a lot of guesswork.

Now, I’m happy to report, some manufacturers are surmounting the obstacles of wood-burning ovens by switching to gas fuel. While the manufacturers I interviewed agree most chefs prefer to cook with a wood fire, they also admitted that market pressure (in the form of operators who aren’t set up to use wood all of the time) has led them to develop gas fired units.

I have been following the various ups and downs of these new technology units for almost two years. After hands-on testing with several of the models and visits to the manufacturers for demonstrations, I am finally satisfied these ovens can produce pizzas nearly identical to those produced in wood fired ovens. These new models feature essentially the same stone hearth as traditional wood-fired units.

And although each manufacturer uses a different approach to the new gas technology, the overall performances of the ovens are very similar. 

Why Gas?

You don’t have to be a rocket scientist to master a wood-burning oven, but getting things right does require a bit of training and labor, which many employers are reluctant to provide.

The number one advantage of the new gas ovens is simplicity. Just flick the switch, set the thermostat and, viola!……….even, constant heat, at the desired temperature. No more watching the fire to get the embers just right, no more forgetting to stoke it up between service intervals, no more guesswork, period.

And there’s no more wood to deal with, either. Many areas throughout the country lack a consistent source of reasonably priced and cured hardwood. In some instances, municipalities have placed moratoriums on all wood burning appliances, and disallow the installation of any new ones. Venting problems and restrictions make wood burning units impractical in many buildings.

Operators with space constraints are hard pressed to locate the additional storage area for a month’s supply of wood. Furthermore, many operators see wood as a messy fuel, one that can bring in insects, dirt and dust and they don’t want the bother of disposing of hot ashes. In short, wood-burning ovens intimidate many pizza makers. They want the stone hearth, but without the hassles. Gas fired stone ovens definitely make that type of hearth more accessible to everyone.

While there are many conveniences attributed to these gas fired units, there are some advantages that still speak very strongly for wood burning ovens. First of all, philosophically, a wood burning oven remains the genuine baking article for the master pizzaiolo. The visual effect of the warm flickering wood fire as well as its smoky aroma and flavor are missing. (This does not affect pizza all that much, however, because it bakes so fast in these ovens that it does not have the time to develop a real smoky flavor.)

Wood burns hotter and drier than gas, so BTU for BTU, wood cooks more quickly and more efficiently than gas. I cooked in two Wood Stone models side by side, a gas fired unit and a wood fired unit, and even with both models reading the exact same temperature, the wood-fired unit baked the pizza 25 percent faster. A 10-inch thin crust pizza cooked in 3 minutes in the wood fired unit, the same pizza, placed in the same spot in the gas fired oven, took 4 minutes.

There is also a slight difference in crust color and texture. Gas heat produces a slightly chewier, cooler brown colored crust than its wood burning counterpart. This slight difference can be attributed to a more moist heat from gas as opposed to the dry wood heat. These differences are so small, however, that only true pizza aficionados can detect them. A bit of tweaking with the crust recipe could fix that quite easily.

The Test

The test pies I always use are 10-inch thin crust, hand-stretched from a 7-ounce dough ball. The dough recipe is configured for optimum use in a wood-burning oven. The pies are topped with 1 ounce of pizza sauce and 3 ounces of mozzarella cheese.  

Bravo Systems International

The interior brickwork of these ovens looks like an old-world work of art. Handcrafted in Italy by a family that has long been in the business of build­ing wood-fired ovens, these ovens are constructed with special bricks made of high-fired cotto refrattario. The bricks are massive, forming walls four to six inches thick. They have excellent heat retention qualities, and hold up quite well under any commercial situation. They are built to last.

The gas burner, which puts out about 160,000 BTUs, is made of solid stainless steel. The burner is placed off to the sidewall of the oven and has been designed to imitate the soft feather-like flame of a wood fire. The setup is really quite simple: The gas controls are under the front shelf and accessible when service is necessary. Bravo custom configures each gas fired unit. The size of the burner will depend on the size of the oven unit. The idea behind these units is to keep them as simple as possible, like their wood fired counterparts. These ovens are not only beautiful to look at; they’re tried and true in the field.

Earthstone Ovens

These handsome looking ovens have been the most closely designed to work and look like an actual wood fire unit. The heavy duty burner is recessed in the oven floor, so only the flames are visible. Special ceramic logs placed in front and over the flames take on the distinctive look of a flickering wood fire. The burners have been especially designed to create a golden colored feathered flame effect that mimics the soft, licking flames of a wood fire as opposed to the bright blue torch jets of a gas fire. The ceramic logs aren’t just decorative.

Because they are made of the same refractory material as the oven, they absorb heat and act as an extra heat source, similar to live wood embers.

The gas flame never goes off. There is a dual flame level of low and high. When it reaches the selected temperature, the high flame cuts out and the low flame remains. This continuous presence of the low flame replicates the constant low heat of a wood burning fire. Set in a box just underneath the opening of the oven, the controls are easily accessible. Earthstone uses solenoid based controls, as opposed to computerized ones, for easier diagnosis, faster repair and less costly replacements.

These ovens, made from dense refractory material manufactured by La Farge and cast at Ephrem Productions in Manosque, France, are fully assembled in the United States by Earthstone. The pies I prepared in Earthstone’s gas fired unit most closely resembled wood fired products in texture, and had the fastest baking speed of all the gas fired units tested for this piece (3 minutes for a 10-inch thin crusted pizza). With the fire off to the side, gently flickering through the logs, this unit most resembles a wood fired oven in fire appearance and in cooking ability. All that’s missing is the aroma.

Rosito Bisani Imports

Another Italian import, these family crafted ovens are made by a manufacturer in the Genoa area of Italy. Rosito Bisani offers two versions of gas fired units: one a combination of wood and gas, and one all gas. Rosito Bisani’s ovens are made from poured and vibrated refractory material, creating a very dense stone. The oven walls are four to six inches thick throughout

The wood and gas combination works only with both gas and wood, or wood alone, but not gas alone. Only the all gas model can be fired with gas alone. The wood/gas combination is essentially a wood burning oven, but with a gas burner under the oven floor that acts as a kind of gas assist or gas back up. The oven can be heated with a wood fire alone; the gas burner underneath gives a boost to floor heat and is not capable of heating up the entire oven.

This feature works best for operations with heavy duty, full load production where the oven floor is constantly filled with product. When the oven floor is constantly covered from end to end, it can lose heat at a faster rate, which is where the backup gas heat comes in.

The all gas fired unit has the same burners under the floor and an addition al burner off to the side for the top heat. The controls are easily accessible under the front of the oven. These units are entirely constructed in Italy to Rosito Bisani’s specifications and imported to the United States. All in all, the Rosito Bisani ovens are nicely crafted and made of quality materials.

Wood Stone Corporation

State-of-the-art design and construction characterize these American made ovens. The folks at Wood Stone, like Earthstone Ovens, did not just add a gas burner to a wood burning oven; they redesigned their gas fired stone oven to take the fullest advantage of gas technology. They have reengineered their ceramic “recipe” specifically for working with gas.

Because wood heat is so intensely dry, it is characteristically much more thermo-responsive than gas, which is a moist heat This led Wood Stone to two different stone floor formulations: a highly absorptive formula that allows the slow, steady penetration of intense wood heat, and a less responsive and less absorptive formula that allows for faster heat transference with gas heat.

Wood Stone makes a wood/gas combination and an all gas fired stone oven. The wood/gas combination consists of an infrared burner beneath the oven floor and a wood fire on the hearth floor. The oven works similarly to the Rosito Bisani model; it can be totally wood fired, but not totally gas fired.

The all gas fired model is called a dual-temperature oven because both the floor and radiant heat can be individually adjusted; they are independent gas sources. As a result, they provide greater temperature combination flexi­bility to suit whatever cooking combination may be desired. The all gas model features a bottom infrared burner and a top burner placed at the back of the unit’s floor, so the flame is visible at all times. An advantage of infrared burners is that they heat directionally and can warm up the oven floor more efficiently; unlike flame burners, they optimize the number of BTUs because they provide intense radiant heat The top flame burner provides a non-directional radiant heat that heats up the upper parts of the oven.

I had a chance to work closely with these ovens over several days at the factory and got excellent results. The ovens are sleek and attractive. They heat evenly and are a joy to cook in. Wood Stone may be one of the newer companies producing wood-burning ovens, but they are building ovens that are meant to last a lifetime.

While there are other companies making gas fired units, the ones mentioned in this article are probably the most well known and certainly among the most reliable.

Prices

Commercial gas units range in sizes from 34 inches to 84 inches of interior deck space. The list prices for gas units start at about $5,000 and top out at about $16,000, depending on what features and special options have been chosen. Generally, gas units are 25—50 percent more expensive than conventional wood-burning ovens.