Driving heat across the cooking floor

[dmun]

Re: Driving heat across the cooking floor

Sounds to me that the concrete floor under the firebrick is wicking away the heat. Anyone else agree with that?

Absolutely. Having no insulation underneath means a hot slab and a cold cooking floor. Unfortunately it's not an easy fix. You can build the fire in the center, and rake it over at the last minute before putting the pizza in, but that won't keep it hot. It may also be too hot, charing the bottom before the cheese bubbles.

How's your floor mounted? could you lift the bricks and sneak in a layer of cal-sil sheet insulation? that would give you a little less room in the oven, but it's better than an oven that won't cook pizza.

[oventhusiast]

Re: Driving heat across the cooking floor

Sounds to me that the concrete floor under the firebrick is wicking away the heat. Anyone else agree with that?

[cbakken]

Re: Driving heat across the cooking floor

....when I say that the dome begins to feel warm to the touch after 3. 5 hours of firing, I mean on the exterior of the dome, of course. I wouldn't be foolish enough to try touching the whitened interior!

[cbakken]

Re: Driving heat across the cooking floor

Hi

The diameter of the floor is about 38". The floor is composed of 3" deep fire brick, beneath which there is a concrete pad (but no insulation). The dome is a layer of fire brick, on top of which was plastered about 3" of concrete/vermiculite, on top of which is a layer of decorative stone. After about three and a half hours of firing, the dome itself begins to feel warm to the touch.

I don't have a thermometer, but I fire the oven for about an hour before making pizza. I measure by putting my hand toward the dome and when I cannot count to "one-one thousand," I estimate it's around 700 degrees.

Let me know if that sheds any light on the issue. Thanks for your response.

Goatboy

[Acoma]

Re: Driving heat across the cooking floor

Goatboy, how much area and how thick is the vermiculite, concrete mix? This sounds like the issue. How about heating? What temp do you get up to and maintain?

[cbakken]

Re: Driving heat across the cooking floor

Hello All:

I've been reading this helpful thread, but still need some help. I've got a relatively small oven (the diameter of my cooking surfact is about 34") and I've been cranking out great food, but not great pizzas.

The problem is bottom heat. I get pizzas with perfectly done "tops" but undercooked bottoms. If I pre-cook the crusts for a minute, then top them, I have excellent results. But I think that's just stupid.

I keep active flame on the side of the oven during pizza cooking and have experimented with big fire (flames coming all the way across the dome) and small fire (flame coming 1/4 across the dome), but while both seem to recharge the dome, neither seem to recharge the floor effectively.

Should I be moving the fire pile from side to side after every five of six pizzas? Does this even recharge the floor? Sometimes I feel the floor doesn't get very hot under those big piles of coals on the fire-bearing side.

Any help anyone can offer?

Thanks!

Goatboy

[james]

Re: Driving heat across the cooking floor

Or use a Shopvac after days and days.
James

[DrakeRemoray]

Re: Driving heat across the cooking floor

Interesting, I will have to try that, I have been using a small metal garbage can with a locking lid. I was shoveling coals out the other day, and my dad said, hey, you just made charcoal, but of course, I ignored him....silly me....

Also, I would caution everyone, those coals will smolder for days, don't throw them into the trash for a long long time...

[dmun]

Re: Driving heat across the cooking floor

Great advice all. If you end up with a large bank of coal from firing your oven, you can shovel a good percentage of it out into a steel pail.

The other day I shoveled a bunch of excess red coals into the Weber BBQ, and closed it up with the lid. The next bake I had a load of stick charcoal, which I put in the Weber fire starter,



and it started right up with a piece of crumpled newspaper in minutes, much faster that briquettes. I was able to go from match to hot coals in minutes, ready for logs.

[james]

Re: Driving heat across the cooking floor

Great advice all. If you end up with a large bank of coal from firing your oven, you can shovel a good percentage of it out into a steel pail. Then, as others have noted, you can keep the flame going by adding a few pieces of 2-3" diamater wood. It should combust quickly, which will give you the flame you want in the oven dome. By taking the excess coals out, you will have more room on the cooking floor, without compromising your cooking temperature.

I also think the fire is much better on one side (the left of me), rather than the back (over even on two sides).

James

[Dutchoven]

Re: Driving heat across the cooking floor

Definitely! From the pictures you made a really nice big, crazy fire...but...when it comes time to put the pizzas in you won't need that much volume of coal. I think you could reduce that bank of coals down to about 25-30 percent of what is shown in the pics and then add a piece or two of nice dry wood. Just an active fire that reaches the top of the dome will keep nice heat rolling in your oven. I have to have a larger bank of coals for pizza to combat some cool spots. My oven is a barrel vault much more effective for bread baking...but I can still make some killer pizza!
Best
Dutch

[beammeup]

Re: Driving heat across the cooking floor

Thats a good idea. I was struggling for room. I guess a fresh fire would give off more heat than the coals.

[arevalo53anos]

Re: Driving heat across the cooking floor

Beammeup:

Nice pictures.
Just an opinion, on next time you would like to took the ashes and the most of the coals out and feed the fire with a few new branches.
This will give your oven the necessary live flames to bake the toppings along the bottom of the pizza and there will be a lot of free hearth space to bake too.

Good luck
Luis

[Acoma]

Re: Driving heat across the cooking floor

Beamer, those are superb photos. You must have devoured those pizzas. Big difference w/ coals to one side. More room too.

[beammeup]

Re: Driving heat across the cooking floor

I did 2 things that made all the difference. Huge fire for 3 hrs, then moved all the coals to one side and cooked the pizza on the opposite side. I used to put the coals on either side and cook in the middle. I am very happy with my set up now pizza's were yummy.