Building A Better Fire

[navyintel]

I have not posted to this portion of the forum before, here goes.

I have had my oven in use for about a year and I have been starting my fires the traditional way. In the front, pushing to the back, then pulling it to the sides.

I think I may have a better way that results in a more evenly saturated oven and does not smoke as much. Also, it gets hotter.

What I use is Doug fir. A one hour burn takes about 30lbs of wood nothing bigger than 2x2 inch pieces.

Try this - Build the fire in the mouth of the oven as usual, heating the lip and chimney. Push the pile back about 1/3 and add fuel. When you have coals knock the pile down and make a round burning surface that covers 1/3 of the floor. Bring some of the coals to the front of the oven to make a barrier to air flow. This causes the air coming into the oven to superheat and does not cool the oven deck. Keep adding fuel, but not so much that you have flame over 12 inches high. When the fire is even on the deck push everything to the back of the oven, then pull it back to the center and redistribute the fire evenly in about 2/3 of the oven floor and pull coals to the lip. The trick is to keep hot burning coals on the lip of the oven door as a barrier to air flow at all times. Once you have 20lbs of wood in the oven, clear a clean space in the center of the oven and push all the burning material to the back and sides ? still with coals at the lip. Add fuel to keep the fire even all the way around the sides of the oven. Once or twice, pull all of the burning material away from the walls and front, redistribute all the coals and push them back to the sides with new coals at the lip.

Finish with the fire almost burning all the way out.

This extracts almost all of the energy from the fuel and places it into the brick top, sides and floor. It still takes about an hour of fueling and ? hour to let it burn down. You can then push the burned out coals to the back, or remove them. I leave them in. I let the oven sit closed for about 1 hour. Oven should be well saturated and ready for whatever you want to do.

Now you are ready to use your good wood for flavoring, etc. by starting a new all oak or other hard wood fire, or let it cool down for other cooking.

The purpose of keeping coals in the lip of the oven is to prevent cold air from interfering with the heating up and saturating the oven deck that is most important when making pizza or other hearth breads. It also makes the oven stay hotter longer.

I can get 3 to 4 days of cooking using this method.

What I have found is that it is not how hot you can get your oven, it is how long can you keep a fire going in order to heat up the bricks. In this method, a lower flame achieves the same or better result with less fuel. I have also found that the weight of the wood is more critical than the volume of wood. More BTUs per volume of hard wood, but pretty much the same BTUs per pound. (Hard wood is heavier per volume).

I am interested in anyone who has a comment on this. I hope someone will try this method as an experiment. I am always open to suggestions.

[cobblerdave]

Re: Building A Better Fire

Gudday
That was well written, you describe the process really well I could smell the wood smoke. Totally agree to use of woods other than hardwoods to get you oven to temp. Then using you best wood to finish off... good point to make.
Did you discover like me you have to be prepared for a larger amount of ash than from hardwood which I remove from time to time. I think an excess of ash blocks the air to the fire and insulates the floor from the radiant heat from the dome.
Interesting to hear the bank of coals the entrance side of your fire to preheat the air, Ill be thinking of that next firing and will be giving it a go.
No oven this weekend, hot, but showery, and the wind is gusty, all good reasons not to try
Regartds Dave

[Wambat]

Re: Building A Better Fire

What I use is Doug fir.

Typo ??? Thought it would stink up the place....

Dog Fur that is

PS....
Sorry... my first post on this board....
And my really strange sense of humor

[navyintel]

Re: Building A Better Fire

Good hearing from you,

I agree. That is why I move the coals around in order to get the hot stuff onto the oven deck. I have not taken out any ash because the doug fir is so light that the ash is small relative to the coal production.

Also, I would like to extend and modify my last post by stating that the 30 lbs is not enough fully heat an oven. This is only enough to get the bricks started.

In my oven it takes 1 lb of wood to raise the whole brick dome and hearth by 6 degrees F. So to get to 600 degrees would take over 80 lbs of wood. It would also take 2 hours and 45 min of burn time @ 20 min per 10 lbs.

But I would not want a fully saturated oven at 600 degrees because my oven drops at 5 degrees F per hour when saturated. That means It would be 20 hours before the oven was at baking temp.

[TropicalCoasting]

Re: Building A Better Fire

Does anyone in Australia have some figures on how much hard wood it takes to get the oven sorted.
Im assuming 42 is the standard
but
Im willing to go smaller

Do people use a bit of wattle or palm fronds to get it started?
Im trying to do the maths on how much wood Im going to need everytime I fire one up.

[GianniFocaccia]

Re: Building A Better Fire

Excellent post, thank you.

I had not considered the effectiveness that airflow from front/center coals creates in heating the floor. I'm hoping this will help as I test heating a 3cm soapstone floor sitting atop standard firebrick.

I would imagine that if this process works well for you in AZ, it would provide significant benefits for those with snow on the ground.

[navyintel]

Re: Building A Better Fire

It should work well for you. I picked up this idea watching a youtube video of some European bakers making pizza. Their chimney was in the rear and all of the hot air built up in the oven was washed out by the influx of cold air from the front of the oven. They built the wall of heat using a very high wall of coals.

I adopted the idea and adapted the process to be a fairly low threshold of coals and burning fuel (just a few inches) but fully blocking the entire entrance.

So far so good, longer burn times with less fuel and a well saturated brick all around.

Note: I fired it up at noon yesterday and got it to even out at about 520f on the floor and this morning I put in 2 x 2 quart old style pot belly bean pots. One with traditional Boston Baked and one experimental BBQ bean recipe trying to get close to the Wilbur Beans at Famous Dave's - using some old pulled pork and thick bacon.

[shuboyje]

Re: Building A Better Fire

I've been firing my oven a similar way for a while now. I build a fire and let it burn down to coal. I then spread a thin layer of coals over the entire oven floor, leaving a small wall at the entrance and the bulk in a pile at the rear of the oven. All the additional fuel is added to the pile in the back of the oven. The coals on the floor use all the oxygen before the air gets to the coal pile in the back of the oven. This causes the material in the back of the oven to undergo pyrolysis and begin giving off flammable gases. These gases rise into the dome and move toward the front where they hit the oxygen rich air and combust. You end up with very hot bed of coals, and an intense wall of fire that is using all the heat in the wood efficiently and heating the oven quickly.

[V-wiz]

Re: Building A Better Fire

Interesting idea, but may i ask why you guys build and start the fire at the entrance? In my case i build my fire inside at the middle, i put my blast door on for 30 second and everything is perfectly lit and smoke goes up the chimney without a problem.

[wotavidone]

Re: Building A Better Fire

Does anyone in Australia have some figures on how much hard wood it takes to get the oven sorted.
Im assuming 42 is the standard
but
Im willing to go smaller

Do people use a bit of wattle or palm fronds to get it started?
Im trying to do the maths on how much wood Im going to need everytime I fire one up.

Apart from 42 being the answer to life, the universe, and everything, (proving that there is something fundamentally wrong with the universe, apologies to Douglas Adams), I don't quite get what you mean.

However, I believe cobblerdave uses palm fronds to heat his oven.
Apparently this is a free resource that would otherwise present a disposal problem.

It doesn't take a lot of wood to heat my 30 inch to white. One day I'll cut a wheelbarrow full of wood and see how much I have left after a decent pizza party.

I suggest it won't really take a lot of expensive wood to heat any oven.
The thing is, while I like to use low ash timber, I also find my oven heats better if I use thin sticks to get a nice raging fire going. This means I commonly find myself picking up the thin branches of redgum that the serious firewood collectors leave behind.

[cobblerdave]

Re: Building A Better Fire

Interesting idea, but may i ask why you guys build and start the fire at the entrance? In my case i build my fire inside at the middle, i put my blast door on for 30 second and everything is perfectly lit and smoke goes up the chimney without a problem.

Gudday
I use the top down method and build my fire in the front of the oven and get it flaming and the chimney hot. It's a simple case of pushing it in to the middle of the oven and it will do its thing . Advantage I find is that it easy to build the fire in the front no reaching in. Heats the chimney so it draws well from the start. Recon there's less smoke as the fires pretty hot already when it arrives in the cold oven. I'd recommend you give it a try can't hurt.
Regards dave

[cobblerdave]

Re: Building A Better Fire

Does anyone in Australia have some figures on how much hard wood it takes to get the oven sorted.
Im assuming 42 is the standard
but
Im willing to go smaller

Do people use a bit of wattle or palm fronds to get it started?
Im trying to do the maths on how much wood Im going to need everytime I fire one up.

Gudday
Recon Micks s about right with the small sticks and the 1/2 to 3/4 of a barrow of wood. Sticks burn fast and hot and give you good heat plus there's little or no chopping large logs into smaller bits.
As for burning wattle its an acacia and they have a high tannin content. Of course they burn but tend to produce a acrid smoke as long as you burn them at the beginning not the end when they might taint your food.
I burn the fallen palm fronds as well again the smokes not sweet. If there are not complete dry it doesn't matter they burst into flame instantly in a hot oven. They burn fast so its one at a time till there are gone.
There was a time that I didn't take out the excess ash but now I do as it can insulated the floor from the heat from the dome and active coals. It's a pain playing with hot ashes but it works out better.
Hope something here might help.
Regards dave

[Greenman]

Re: Building A Better Fire

I use a variety of timber to get things going. Most of it is dense hardwood but being a 'harvester' I can tell you that mangrove displaced by the floods is good starting wood when it eventually dries out. Some of the eucalypt s are good for quick heat but the really dense timber like ironbark and the like are great to maintain temps when used as larger pieces.

I have a supply of timber from old well dried stumps and roots that is as heavy as lead and burns for a very long time.

The term 'scrounger' has been discussed on the forum before and when it comes to fuel for the forno, anything that has not been treated or doesn't emit anything nasty is good to go, including the well dried prunings from the garden. I am aware the the term means different things but in the sense of recycler it is good for me.

I am a bit lucky with being in the country rather than the city but even in the city there are opportunities for the keen scrounger. Storms bring down trees and branches and they need to be removed by someone, and if you have a chainsaw............

[navyintel]

Re: Building A Better Fire

Gudday
I use the top down method and build my fire in the front of the oven and get it flaming and the chimney hot. It's a simple case of pushing it in to the middle of the oven and it will do its thing . Advantage I find is that it easy to build the fire in the front no reaching in. Heats the chimney so it draws well from the start. Recon there's less smoke as the fires pretty hot already when it arrives in the cold oven. I'd recommend you give it a try can't hurt.
Regards dave

I agree with cobblerdave: It not only heats up the chimney which improves the draw, but it heats up the top lip of the oven door. When the lip is very hot the gasses in oven pass over the lip quicker - its almost as if it becomes slippery. The overall effect again is ease of fire build - Hot coal barrier at the door to eliminate cold air going in (like in Detroit -what -40f?) - Hot chimney and a hot door top. When you try it as described, let me know how it works - we can always adapt new methods.

[V-wiz]

Re: Building A Better Fire

Gudday
I use the top down method and build my fire in the front of the oven and get it flaming and the chimney hot. It's a simple case of pushing it in to the middle of the oven and it will do its thing . Advantage I find is that it easy to build the fire in the front no reaching in. Heats the chimney so it draws well from the start. Recon there's less smoke as the fires pretty hot already when it arrives in the cold oven. I'd recommend you give it a try can't hurt.
Regards dave

Thanks Dave, ill give it a try