Sub-Zero Brick Oven

I've just returned from one of the coldest parts of the country (lower 48) where I built a residential brick oven core.

Aside from using every trick to keep the mortar and materials (not to mention me) from freezing, I incorporated combustion air chambers and the custom damper system that my welder and I have designed.

The location, near Potsdam, NY dropped to lower than minus 30 while I was there. 

pot heater inside the woodbox area

Now, back home, I'm preparing for projects lined up for the spring, including a new French style portable oven that I will take to the Northern New England Home and Garden Show for chefs to demonstrate brick oven cooking.

combustion air channels left and right

Brick Oven Combustion Air

First fire with perfect draft (right makeup air channel visible)

Brick Ovens, like all fuel based devices, require combustion air for the wood to burn.  Insufficient air and the wood burns inefficiently. Too much air and the oven cools faster than it heats or is also inefficient.

smoke stays in the chimney

left side makeup air channel (partly closed)

In places where the oven is part of an indoor environment, the combustion air will be taken from wherever it is available (doors, windows, heating system, etc.)

Where there is negative air pressure in the space due to other exhaust fans, smoke may come down the chimney and make using the oven impossible.  Other factors effect draft, such as chimney height and size.

In the recent brick oven build at Brewster Academy, two makeup air chambers were built into the masonry that surrounded the flue space.  These provide immediate and passive air equal to the rate of natural draft the chimney provides while also giving the fire combustion air precisely where it is needed.  The openings can be adjusted and the chimney has a damper for when there is no fire in the oven.

As a late-arriving detail, this solves a number of issues that indoor wood-fired brick ovens face.

I always try to make improvements based on my continuing experience building and using brick ovens.

Brick Oven Advantage

Immediately upon finishing the Brewster Academy wood-fired brick oven, and the workshop on firing and baking, Executive Chef Chris Dill went full forward with cooking a wide variety of foods for the students at this private school.

Mary Roetger put together a time-lapse video of the project.  https://vimeo.com/84314167
Thanks to all the dining staff and the people at Brewster who helped make this happen.

Day One of a New Brick Oven

After weeks of construction, the day that we begin to really cook is a celebration.
I was joined by Michael Jubinsky of Stone Turtle Baking School, who gave the dining staff a how-to on oven management and Executive Chef Chris Dill of Brewster Academy, where the oven is located.

Brick Oven Stone Face

Finishing the presentational face of a brick oven presents many aesthetic choices.  The most recent oven, in the dining facility of Brewster Academy in New Hampshire, was designed to echo the design of the fireplace in the same building. 

However, as an oven with an arched mouth and face, the use of the granite shifted from a simple rectangular framing to the segmented classical arch.   The base and shelf stone slabs were built with a corbel for decorative and structural purposes.

The makeup air vents and the sides and the ten inch flue worked perfectly.

Brick Oven Face and Flue

The final phase of the Brewster Academy wood-fired brick oven in Estabrook dining facility is at hand.

Once the core dome was complete, with additional mass (9"total), the face arch was built, the make-up air channels and the flue were formed as the front wall of the oven leveled off and was finished to just below the ceiling with concrete block.
Veneer stone (granite slabs and Stoneyard brand Boston Blend will face the oven front.

Brewster Academy Brick Oven Project: The Dome

level used to check arch form

form removed and bricks cleaned

Last chance to work from the inside

Dome top  center awaiting last 3 chains

Dome bricks above mouth fitted and chain are continuous

Having cut the hundreds of bricks for the dome ahead of time, the laying up of the 'chains' progressed rapidly.    The mouth form, 24" wide on this oven, is set in place long enough for the arch bricks to be mortared, then removed within an hour so that the undersides of the arch bricks can be cleaned of mortar.