By Ann Rudorf, Wood Stone Residential Chef
If you build wood fires in your oven, (either wood-only or wood/gas combination) you’ve no doubt heard our adage “Burn only seasoned hardwoods with a moisture content of 15-20%.” Perhaps you’ve wondered, “Why do they stress this? How does one determine moisture content? Does the species of wood really matter?” Here are some quick answers.
First of all, if the wood has a moisture content of over 20%, more of the BTUs are being used to “boil” the water out of the wood instead of going into heating the oven. Your goal of heating that stone hearth and dome is compromised and inefficient. Creosote build up is also an issue with wet wood. (20% moisture content wood produces twice the creosote of 15% moisture content wood.) It’s worth noting that wood with a moisture content of 10% or less will have lost much of its density, burning too quickly to leave sufficient coals. Use a Wood Moisture Meter to assure that fuel wood has the proper moisture content even before it is unloaded from the truck. (Note: Always measure moisture from the center of a freshly split piece of wood.)
We also stress using a good, heavy hardwood such as Oak, Apple or Hickory. You will get more heating BTUs out of a 4600 pound cord of Oak than a 2800 pound cord of Birch. Hardwoods also produce a better bed of long-lasting coals than lighter woods with a more balanced “coals to flame” ratio resulting in a better balance between floor and dome temperature for more successful cooking! Refer to our Wood Burning Oven Fuel Facts for the weight per cord of wood found in your area.