Fire Placement

[splatgirl]

Greetings
I think I discovered something by accident last week.
I have always adhered to the idea of moving and keeping the active fire to one side of the oven once it's up to temp for pizza cookery. As you know the thinking is that the heat from the flames licking up the side and to the top of the dome gets reflected back down to recharge the hearth and keep it hot. And it works great, but I do find that I occasionally need to rake the coals back over the central part of the hearth to return it to ideal pizza temp even though I try and keep a decent amount of flame going all the time.
Well, for whatever reason (lazy &/or forgetful), last time I fired I ended up pushing my active fire to the center back of the oven and maintaining it there. The surprise was that it seemed to have been more effective at keeping the hearth hot-hot. Almost to the point of being too much, so that I had to back off on the size of the active fire that I would normally keep.
I'm going to try this again next time I fire up just to see, but in the mean time I'm wondering if the way it was drafting being directly in line with the flue was what made it more effective at recharging the hearth, or if it was related to the outdoor conditions that day, or something else. It produced some of the most perfectly cooked pizzas I've ever done.

If anyone else gets a chance to try this compared to the side-fire method, I'd love to hear your thoughts.

[texassourdough]

Hi Splatgirl!

I started with the fire in the back and on my second pizza I didn't really get the peel under the pizza and I snapped my wrist forward and jammed that sucker right into the coals for an instantaneously charred pizza. And after thinking about it I decided to move the fire to the side so if I did it again I would only shove it into the back wall. It has never happened again so I don't really have a a lot of data to say keeping the fire on the side has advantages...

Your experiment is interesting. I am not sure why it should really make much difference if the air flow in the oven is good except that I would think the side the only air the pizza sees is "fresh" air as the air should go in on the cool (pizza) side and exit on the hot (fire side creating a circular path through the oven. As a result the dome would be hotter on the fire side. With the fire in the rear the dome should be more uniformly hot as the hot air must go all the way across the oven to get out. I may be able to check this out with my infrared thermometer.

Good question and observation!
Jay

[david s]

I usually use a fire on the side because my oven is small and I can easily reach into the entry and place wood onto the fire (quickly) by hand. Reaching all the way to the back is more difficult, but I will try the fire at the back next time and see what happens.

[Neil2]

"last time I fired I ended up pushing my active fire to the center back of the oven and maintaining it there. "

I usually push mine to the back.

[dmun]

The problem with fire in the back is that you can't keep an eye on the edge of the pizza directly exposed to the flame, and charred edges are more likely.

[Neil2]

I turn mine frequently.

[GotRocks]

Did you do anything else differently besides having the fire to the rear as opposed to the side? Did a you use wood from a different pile, a different vendor, a different species? Maybe the wood for that burn was more seasoned (less moisture content) and that has created the discrepancy that you stated?

The oven is a dome, the angle do not differ from side to side, or from side to rear, it should all reflect evenly no matter where you burn you fire at. Thinking along those lines though, did you check to see if all the interior angles of the walls are equal to each other? Is there a difference in angle or height from the deck in the curvature of the dome which may have caused a different heat pattern by where the fire was placed?

I think it is the amount of heat produced by the wood you used last time, it may be drier and able to produce more BTU's per pound, or a different variety with the same results.

Please report back in regards to the type or source of wood, you really got me curious with this now.

[splatgirl]

same wood, a month older than the last time I fired. Dome has got to be within a degree or so of perfectly domed, as I used the "Hendo's dome gauge" method for my build.

I really think it has something to do with the air flow and being directly in front of the flue vs. to the side. In my head that means that the hot air gets sucked directly and evenly over the top of the pizza. Obviously I have no way to test other than to try it back to back with a side fire under relatively the same outdoor conditions. If and when that happens, I'll be sure to report back. In the mean time maybe others will try and we can compare notes.

[Archena]

Hmm, just a guess but in the back air flow would probably be more direct, i.e. the incoming air would head directly for the fire rather than swirling around inside the oven. The more air, the hotter the fire.

[trockyh]

We went to the FB Expo and Antonio (one of the chefs) mentioned finding the ying and yang of your oven. He also used the term masculine/feminine for the fire/heat management. Every oven is different, but he talked about finding the balance between the back and side of the oven. I do prefer the side so I can keep an eye on the crust.

Tom