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Alan Scott - Ovencrafters

Bakeoven Seminar with Alan Scott
Masonry Heater Association Annual Meeting,
Las Vegas, March 1995

Alan Scott is an Australian-born craftsman whose first trade was as a blacksmith. He is now a baker and a well-known designer and builder of wood fired brick bakeovens, both domestic and commercial. He makes his home in a rural setting north of San Francisco, where he practices the various aspects of his craft. We had the opportunity to build one of Alan’s ovens four years ago for a small commercial bakery outside of Ottawa. I was impressed with some of Alan’s design innovations that resulted in a low cost, easy to build oven. After three years of commercial use, the owners report that they are very happy with the oven’s performance and in fact are planning to expand and build a larger oven. Fuel cost per loaf of bread is two cents.

Features of the retained heat design. Alan started his presentation by describing some of the features of his retained heat design:

• The largest size oven has 6 foot by 8 foot hearth area.
• The vaulted baking chamber ceiling consists of 4.5 inches of firebrick capped by 2 inches of reinforced concrete (thus cleverly eliminating the need for traditional structural steel to take up the vault side thrust.)
• The ratio of door height to dome height is 63%.
• The oven is filled with wood, and a fairly slow fire results in a very evenly heated oven.
• Smoke exhausts at the top of the door where it goes into a collection hood.
• The dome is kept as low as possible, which provides the maximum amount of steam.
• For breads, a 15" high dome with a 10" door is close to ideal, while an 18" dome with a 12" door is more versatile for restaurants.

Techniques for larger ovens. For larger ovens, more support for the arch needs to be provided during construction. This can be done by pouring the concrete supports for the sidewalls first. For restaurants, calcium aluminate concrete is used. The thickness of the arch is increased if more batches per firing are needed. A 6" arch will give 8 batches, while the standard arch gives 4 batches - more for lighter bread. Heavy breads require a hotter oven. This requires a more tricky firing technique, and this is one drawback for this oven style. Hearths should be smooth, with bricks laid up on edge, dry, onto a sand bed. Soapstone is too conductive and results in too hot a hearth. Castable refractory hearths have peeling problems. Allan’s philosophy, and advice to oven builders, is to keep it simple. This is exemplified in the traditional Québec oven which, however, is not as efficient.

Shown below is an oven built by Allan Scott at the Cafe Beaujolais in Mendocino CA. The oven has been in service for about 8 years. Click on image for an enlarged view.

Bread is the starting point. The starting point for oven building should be the bread. Alan advocates a switch to a more appropriately scaled economy and lifestyle, and his oven designs and his bread reflect this. Pizza ovens use a continuous fire in the oven during the baking. This automatically results in the required high air temperature (700F). This same style of oven is used for middle eastern food such as pita, matzoh, etc. Bagels are also done this way. Using this type of oven is labor intensive and requires a lot of skill. Storage capacity is not really required in this type of oven, and castable refractory is an appropriate material. A small prefabricated Italian oven starts at about $6000, but a homebuilt version can be built for around $150.

The breadbaking revival. The Poîlane bakery in Paris is widely considered to be at the pinnacle of the bread baking art. They use a wood fired brick oven. The oven is hot, resulting in a seared, dark crust. The bakery has recently expanded in an interesting way. Rather than build larger ovens, they have replicated their existing oven design 24 times, with the ovens arranged in a large circle. Each baker has his own village-size oven - about 12 - 14 feet square. An article on Poîlane can be found in the Jan/Feb 1995 issue of Smithsonian magazine. Another article about Poîlane included a photograph of the owner in the local forest, inspecting his firewood supply. Alan feels that this is a right use of wood, and stimulates the forests. (French forestry practices have been enlightened for a long time. France has about 1/7 th the forest area of Canada, but produces a higher dollar volume of forest products. 200 year crop rotations are not unheard of.) One thing that is apparent on the West Coast is that a bread revival is under way. Two good recent books on the subject are The Village Baker by Joe Ortiz and Bread Alone by Daniel Leader and Judith Blahnik.

A brand new book, and perhaps the best one so far, is: Breads from the La Brea Bakery by Nancy Silverton.

Bakery visits. Alan handed out a list of ovens that he had built, and we had the opportunity to visit two of them on our drive from Las Vegas to Vancouver.

We also visited several other notable bakeries. Jerry Haupt arranged a visit during a burn for Patrick Manley and myself to the Black Diamond Bakery in Black Diamond, WA. They have a woodfired bakeoven with a 10’ x 12’ hearth that has been in continuous use since 1902. Wood consumption on this oven is quite high at 0.5 cords per day. My guess is that this could be cut by 75% using modern materials and techniques. We also visited Acme in Berkley and Gail’s in Capitola CA.

Ideal firing technique. Alan finished his presentation with a discussion of firing techniques:

• Any type of wood is suitable, and it is a nice niche for limb wood, around 2" in diameter.
• Long lengths can be used, around 4 to 6 feet.
• Diameter should be larger for softwood. Larger diameter wood results in more of the heat going into the hearth, and vice versa.
• A kindling fire is built in the mouth of the oven, and the fire is allowed to burn slowly to the back.
• The fire can be encouraged by raking the coals.
• If you reload, then you cut off the air supply to the first load. You have to wait for the first load to burn before adding wood.
• The front of the oven will be a little cool because of the air supply. Coals are raked to the front as the last thing.
• A damp mop is used to remove the ash from the hearth.
• Allan uses a wooden door plug cooled with a damp terrycloth. The bread is done when the towel starts to burn.
• The widest door for a 48" oven is 24". Usually the door is 19", to fit a standard 18" pan. There can be problems with doors that are too wide, ie., if automatic loading equipment is used.
• Firing times for a 4 x 6 oven are approximately as follows: from a cold start - 3.5 to 4 hours; a warm oven - 2 to 2.5 hours; third and subsequent days - 1.5 to 2 hrs.
• Preheat the oven the night before - it doesn’t take much more wood.

Additional tips:

• A good rhythm is to bake 2 days per week. At the Cafe Beaujolais in Mendocino, the oven is usually 425F in the morning. They prestack and bake the wood.
• Good sourdough bread will last for several weeks. The fermentation that the yeast undergoes in sourdough bread is important - it adds nutrition, and makes the bread more digestible. The challenge is not to make the bread too sour.
• For rye bread, a cool oven is used, around 300 degrees. Steam the bread while baking, and then leave it for 24 hours.

Afternoon Technical Session: Dale Hisler

After Alan’s presentation, longtime heater mason and baker Dale Hisler shared some additional tips with us.

• Dale recommends the installation of an ashdrop at the back of the oven.
• One way to gauge oven temperature is to sprinkle some flour onto the floor of the oven.
• Dampers are an important element for regulating oven temperatures.
• For sourdough, a starter can often be made from existing sourdough bread.
• Steam can be added by installing copper tubes to trickle water onto the oven floor.
• Large ovens tend to have complex damper systems, and a personality.

  ---

New York Times, Feb 6/09

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