Heat Management – Cooking with Wood

 

Managing temperature in a wood-fired oven starts by establishing a target temperature. We recommend a 30 °F temperature “window” to provide a consistent cooking environment. By maintaining a consistent amount of open flame, it is easy to keep the oven temperature within your established window.

By practicing consistent product rotation through temperature zones on the floor, your pizza/product will always cook the same way (see the Pizza Rotation section for details).

The temperature window will be specific to your situation. In the example below, our 30 °F temperature window is 535–565 °F, which we recommend as a starting point.

 

Fire Placement

Build your fire 12 inches (minimum) inside the oven doorway. This placement makes it much easier to reach into the oven to manage your fire or remove ash.

Caution: Do not allow the open flame into the venting area above the doorway (the metal transition leading to the flue). If flames are spilling out of the door opening, or if the oven floor temperature exceeds 850 °F, you are over firing the oven.

 

Building the Fire

It takes approximately 1-1/2 hours to establish a coal bed.

  1. Using the Particle Shovel, remove about two-thirds of the fly ash, leaving any live coals. The coals and ash will help start the new fire faster.
  2. Lay the initial log parallel with the dome approximately 12 inches inside doorway.
  3. Lay 2 or 3 pieces of wood across (perpendicular to) the first piece.
  4. Using a fire starter (not paper), start the fire. After the initial wood catches, it will probably take 2–3 more pieces to establish a 8–14 inch flame, which will take approximately 60–90 minutes.
  5. Do not over fire the oven. During initial heat-up, no more than three or four pieces of wood should be added at a time. Flames spilling out of the oven are not safe!

If you need to build a coal bed in a hurry, use smaller pieces of wood and manage the fire closely. Wet wood takes longer to start burning and requires a larger coal bed to maintain the same amount of heat compared to wood with the optimum 15-20% moisture level.

buildingFire1Allow the fire starter to establish. buildingFire2Moving the fire starters into position using a peel. buldingFire3Start with four 16-18 inch pieces, 3–5 inches in diameter. It will probably take 2–3 more pieces to establish the fire.
buildingFire4Start-up fire will be about 18–24 inches
high. Note thick smoke layer at outset.
buildingFire5Established fire will be about 8–14 inches high after 60–90 minutes. Wood placed on established coal bed will ignite immediately.

 

Maintaining Your Fire/Temperature

Temperature ReadoutAfter you have the floor temperature within your temperature window as shown on the Digital Hearth Temperature Readout (535–565 °F in this example), it should take two pieces of wood about every 20 minutes to maintain a consistent cooking environment (8–14 inches of open flame working on the coal bed). Wood placed on an established coal bed will ignite immediately. Note: A higher temperature window will require more fuel.

Excessive open flame creates too much top heat and your product will finish on the top before it is done on the bottom. Too little open flame will finish (or potentially burn) on the bottom first. For this reason, it is important to maintain a consistent flame height.

Efficient combustion is important to your fire. Place new log(s) across (perpendicular to) the last log that was placed on the coal bed to help maintain maximum combustion air.

MS-5-Night-door

At the end of the day, place the stainless steel Night Heat Retention Door(s) into the doorway to help retain heat in the oven. Night door(s) should only be used overnight.

 

Ventilation Management: A Safety Issue

Burning any wood product creates creosote—a flammable residue. Safe and proper flue management is the responsibility of the restaurant. Fuelwood quality, CFM (cubic feet per minute of ventilation air) and the amount of grease-laden vapors produced are all determining factors in the amount of creosote buildup, and will vary from installation to installation. The exhaust system should be inspected and cleaned per the manufacturer’s and/or local code official’s recommendations. Wood Stone recommends cleaning and inspection at least monthly on any ventilation system serving solid fuel equipment.

 


Wood Quality

Wood that is not properly dried and sized is a common operational problem with solid fuel cooking equipment.

Harder, heavier wood species generally burn hotter and longer. Oak, Apple, Hickory, Pecan, and Mesquite have a very balanced open flame and produce long-lasting embers, and are well-suited for cooking in wood-fired ovens and charbroilers. Hardwoods produce more BTU/hr/pound, requiring less labor to maintain the same amount of heat.

Optimum-sized wood will have an average length of 16–18 inches and diameter of 3–5 inches (either full logs or the sides of split wood).

Lighter species burn faster and cooler, generating more open flame, thereby increasing the challenge of balancing floor temperature/ bottom heat with top heat.

 

Heat potential is measured in BTU/hr/pound. For example:

  • A pound of wood at 15-20% moisture produces approx. 6,500 BTU/hr/pound.
  • A cord (4′ x 4′ x 8′) of Oak weighs 4600 pounds, while a cord of Birch weighs 3000 pounds.
  • Assuming a 15-20% moisture level, it is fairly easy to see you would need a lot more Birch to maintain the same amount of oven heat that the Oak creates.

 

Ideal moisture levels fall between 15–20%. If wood contains more than 20% moisture, it should not be accepted for use. Accurate moisture readings are taken from the center of a freshly split piece of wood. Wood should be stored in a covered area that allows good air circulation so the drying process can continue. (Follow the recommendations in Chapter 14 of the National Fire Protection Association Standard (NFPA 96), and/or local codes for safe wood storage and handling practices.)

Because most wood is sold for heating, it is often only cured for 4–8 months, rather than the 12–16 months required for cooking. It is important to buy wood that has been cured adequately. Indicators of high moisture content include hissing (20–25% moisture level), or bubbles forming out the end (moisture higher than 25%).

Note: Wood at higher moisture levels produces more creosote residue, which accumulates on the flue lining and exhaust hood, increasing the risk of fire.


Fuelwood Facts

Each species of wood has different characteristics. The table below should help weigh the pros and cons of various types of wood. Wood from conifers (pine trees) is not recommended due to its poor fuelwood characteristics (low weight, low-med heat, poor coaling, high sparking and high residual creosote).

table

 

fuelwoodCalcs

 


Optional Wood Related Accessories

 

Wood Stone offers durable, commercial-grade accessories designed for efficient kitchen operation, and to help you get the most out of your wood-fired equipment. See the Tools & Accessories section for our complete line of tools and accessories.

 

 wood cart Wood Stone’s stainless steel Wood Handling Cart is designed to address the day-to-day issues of transporting fuel from the main wood storage area to the solid fuel appliance. The 6.5-cubic-foot capacity cart is constructed from 14 gauge stainless steel. The cart is designed to hold 18-inch logs and to contain the accompanying bark chips and sawdust. It rolls easily over thresholds and carpeting on durable, 3 x 7/8 inches, fully revolving, non-marking casters. This piece is built for a lifetime of reliable use.
 Ash-dolly The Wood Stone Double Compartment Ash Dolly is an efficient and safe means to store and transport the ash that needs to be removed from the oven each morning. It has two compartment sleeves for ash storage. After the first sleeve has been filled, the second sleeve should be filled. By the time the second sleeve has been filled, the first will have had time to cool and should be safe to dump. By separating the ash into two compartments, it is easier to control the disposal of leftover ash in a safe manner. The unit comes with a lock eye and a brass security lock with two keys. The unit is made of 16 gauge stainless steel with a non-marking perimeter bumper edge. It has four non-marking, fully revolving low profile casters.
 mini-Ligno-moisture-meter Wood Stone’s Mini-Ligno E Wood Moisture Meter instantly measures the moisture content of any type of wood, ensuring proper moisture content. Press the probes into the wood surface and the meter quickly displays the moisture percentage on the easy-to-read scale, ranging from 6–36%. An extra (longer) set of probes is included. The meter uses one 9V battery, good for 5,000 readings. The meter and the cap are built of high-impact plastic for years of use. The pocket-sized meter measures only 6 x 3 x 1 inch and weighs 6 ounces.
 Fire Horse The Wood Stone stainless steel Fire Horse can help make your wood fire more efficient. The Fire Horse props up the logs, elevating them off the floor to allow more air to feed the fire.