Developing a fireless oven for retained heat baking and roasting
The fireless oven is an extension of the haybox concept, except it strives to roast and bake via heat-radiating substances instead of boiling everything in a relatively large quantity of water. In the 1910s, the heat radiating substance was soapstone.
Several months ago, I bought two soapstone fire bricks to experiment with but for prepping purposes, I didn’t have a sensible method of heating the bricks. That seems to have changed with the “free energy” rocket stove.
This morning with the outdoor temperature at 40F degrees and sunshine, I wrapped a room temperature soapstone brick (about 1 1/4″ thickness) in aluminum foil to prevent soot buildup and placed it on the cold rocket stove.
The 1913 book, The Fireless Cook Book by Margaret Jones Mitchell advises to heat new soapstone radiators slowly the first time, after which they are safe to heat more rapidly, so I built my little fire up in the stove accordingly.
The test to know when your soapstone brick is ready for baking is to sprinkle a wee bit of flour on the surface. When the flour begins to brown, the brick is hot enough.
This occurred in 25 minutes of lighting the first twigs and gradually building the fire. The top surface of the brick registered about 469F degrees.
The energy cost to heat the brick was zero. Possible downside is that you have to feed small fuel into the stove fairly continuously. For me, that was amusement, not a downside.
Finishing this project won’t be particularly cheap as unlike the haybox or Wonder Bag, the insulation has to be non-combustible. So for that I’ll go with ceramic wool furnace insulation, but it’ll take me awhile to get where I can actually bake with bricks! I must say I am motivated!
One last note. We have a cooking option that Ms Mitchell did not – Reynolds Oven Roasting Bags. I put a 3lb chuck roast and veggies in a bag and submerged it in a large quantity of boiling water to make a pot roast in the haybox the other day. The roast cooked in its own undiluted juices and came out perfect.
I checked the safety of the bags. No toxic chemicals are released into the food from the nylon Reynolds bags.