Saturday, March 23, 2013
Production Brick Oven
Production wood-fired brick ovens require that the baking temperature remain even and high for long periods of time. There is not the option of re-starting a fire and re-infusing the masonry with sufficient heat to get the baking results needed.
Three factors will satisfy production needs.
Increasing the mass of the oven (the masonry that holds the BTU's delivered by the fire) is the first and primary goal. For the current production oven at Pietree Orchard, doubling the floor and roof of the oven will increase the capacity to hold steady heat for long periods of time.
The length of the firing determines how far into the mass the applied BTU' reach. This is known as 'soaking' the oven. With increased mass it will be essential that the oven be fired for a long period of time. This may be calculable for a physicist/engineer but ultimately, the firing time will be discovered by experience.
Unless there is sufficient insulation around the mass, the transferred heat of a long firing will continue to travel outwards and be dissipated in the oven surroundings. There cannot be too much insulation. It is only bounded by the dimensions of the oven enclosure. That is why I prefer square or cube-like enclosures for ovens over stuccoed domes. A box can have a huge amount of insulation between the curve of the dome and the corners of the box and ample insulation where the circle of the dome is closest to the enclosure's walls. If it were possible to keep every last BTU in the oven, we could bake forever, but that is equivalent to perpetual motion.
MASS, TIME, and insulation SPACE...hmmm?