coal baked pizza in the Primo ceramic grill

[Jackie Tran]

I have a primo ceramic outdoor oven.  For anyone not familiar with it, it is an oval shaped kamado oven.  It takes charcoal lump as a fuel source.   On a good day I can get it up to 700+ degrees.  Maybe higher but the dome temp doesn't register above 700. 

It makes a great tasting pizza but my issue with it is the ceiling is a bit high so I don't get the charring on the crust like I want.   The fire creeps up the right side charring that side so I have to turn the pie often to get even browing of the rim. 

So how about lower the ceiling?  Well I tried suspending a pizza stone in the dome but it ultimately cracked when I was diddling with it while it was hot.  I then remember reading the thread on the mortarless oven, a sort of redneck pizza oven if you will.

So I borrowed a few ideas from that thread and came up with the solution seen below.  First bake will be tonight or tomorrow.  It's basically a mini oven inside the ceramic oven.  The gap between the ceiling and floor has been reduced to about 3".  With the pie taking up 1-1.5", there should be 1.5" gap above that.  Hopefully that is enough to get a good browning on the crust. 

I'll post pizza pictures if I can work out the kinks and get a good bake.  One concern I have is that it will be hard to get an even bake on the top and bottom.  My goal is to get a good bake in under 3 mins.

[scott123]

I think you're on the right track, but I would suggest a few mods.

The distance from the hearth to the ceiling looks great, but I think the walls are a bit overkill.  The firebricks are going to suck up a lot of heat and could end up prevent the ceiling from hitting the desired temperature.  Can you get a second iron support?  That way you can support the ceiling with just two bricks.  It should also let you center the ceiling above the hearth. The more symmetry you have, the less turning you're going to have to do. I would also move the bricks away from the hearth a bit to allow for plenty of airflow to reach the ceiling.

Lastly, I would go with a high preheat- as hot as you can get, then maybe close the vent/distinguish the flame and let the heat in the stones even out.

[Jackie Tran]

Thanks Scott. Some good ideas. I was going to place a gap b/t the stone and side walls to allow heat up to heat the ceiling.  These bricks are rather thick and don't allow for much movement sideways.  I did pick up some real firebricks today that are thinner so moving them out a bit won't be an issue.

I do have a 2nd bar I can use to support the back end and do away with the back wall. Just curious as to why you think that would work better than having the back enclosed. I assume the enclosed back could trap  and reflect heat.  By having the back enclosed and sides pushed out a bit, I'm envisioning heat rising and then travelling towards the front of the stone and exiting at the front. With the back open heat would escape in front and back. Would that be better? 

Also I want to elevate the stone another 1/2" or so. I want to get the pie as close to the top stone without touching.

Thx

[Jackie Tran]

Ok here's the updated setup using real "firebricks".  The distance between the hearth and the ceiling is about 2.5". 
 
I purposefully used a thinner bottom stone to try and boost the temps in case I couldn't get my oven temp high enough.  I've been having problems getting it over 650 lately and figured with a not so thick hearth I can push the temp to 750 ish?

[Jackie Tran]

So last night's experimental bake using my Primo mini oven.   After loading the firebox full with lump charcoal, I preheated the oven for about 1 hour.  Not all of the coal was red hot and dome temps were around 650.  Waxing and waning between 630-680F as I was opening the lid to check the fire and such. 

Being the impatient person that I am, I went ahead and loaded the first of 2 pies.  I made 2 doughballs, 1 caputo 00 pizzeria flour and the 2nd one with HG flour (NY "elite" style).

First one was loaded with a dome temp of 650F, and a stone temp of 730 ish?  Bottom was charred in under 1 min.  I had a perforated pizza pan ready and slipped it under the pie so the top could catch up cooking.  Pie was rotate 3 times and total bake time was under 3 mins.

[Jackie Tran]

Here's pie #2.  After closing the oven on pie 1, and snapping up a few photos I had let the oven ride for awhile (5-10m).  Checked back and saw that temps were climbing again.   upto 700F dome temps now.  So I let it ride another 15min or so into 750 ish territory.  At this point it could be hotter but my dome temp stops there.

So I dressed pie #2 (a NY'er).  Made this one thicker than I usually like em.  I did a quick temp check of the hearth and got a 1345F reading.    My thermogun only goes to 1000F.  2nd stone temp check shows 1---.   When I see this, it usually indicates a temp above 1000F.   Kept the lid open for a second or so and decided to load the pie. 

Bottom was toast in about 20 seconds.  I slipped a pan underneath and left er cook for another min or so.  These high temps were really foreign to me and I really didn't know how to manage a pie at such high temps.   Guess I'll have to be a bit quicker with the peel the next time.

Even though this NY was toast, the crust was really phenomenal.  I finally got a taste of that "elite" NY pie.  It was very good. 

[norma427]

Tranman,

Great looking pies and an interesting experiment you are doing.   

Norma

[Jackie Tran]

Thank you Norma.  I'm still not satisfied but getting there.   I have always preferred the tasted of pizza coming out of my primo ceramic cooker over the home oven.

My problem has always been browinng the top properly.  The primo by itself will brown a 1/4 of the pie if I put it close to the side of the primo.  Heat travels up along the walls and the walls radiate heat.  So I had to turn the pie often to get even browning.

This set up, once i get the kinks tweeked out should result in a more even bake and less turning of the pie. 

I also was happy to get stone temps of around 1000F.  That's way too hot and resulted in a burned pie, but good to know it's achieveable.   I already mixed up more dough last night and will rebake.  This time I'll thicken up the hearth so that the hearth temps won't be so high and I should get a more even bake. 

[scott123]

I do have a 2nd bar I can use to support the back end and do away with the back wall. Just curious as to why you think that would work better than having the back enclosed. I assume the enclosed back could trap  and reflect heat.  By having the back enclosed and sides pushed out a bit, I'm envisioning heat rising and then travelling towards the front of the stone and exiting at the front. With the back open heat would escape in front and back. Would that be better?

First one was loaded with a dome temp of 650F, and a stone temp of 730 ish?

Ideally, for NY or quasi-Neapolitan pies, those numbers should be reversed.  Your setup is basically insulating the dome/preventing it from getting hot enough.  There's three kinds of heat. Radiative, conductive and convective.  Traditional Neapolitan WFOs involved the burning embers conducting heat to the hearth, but since your heat source is below, your current configuration is mostly convection and radiation.  Radiation is less about line of sight and more about proximity.  Because the hearth is closest to the coals, radiation will cause it to get very very hot- initially.  You could, maybe, put something between the hearth and coals, but with what you have now, the only way I can see getting a proper ceiling temp is letting the coals burn out, keeping the collected heat in the headspace (by not opening the door), and slowly allowing the heat to rise from the hearth to the ceiling.

Convection, in this equation is about rising hot air.  You want to get as much hot air contacting the ceiling as possible.  Those poorly conductive, thermally massive bricks are gumming up the works.  Whatever you don't need for supporting the ceiling, get rid of.  In fact, if you can get 1" wide kiln stands and completely remove the bricks from the equation, you'd  be better off.

[Jackie Tran]

Thanks for the reply Scott.   B/c the way the Primo is set up with the heat source at the bottom, the dome temp is always lower than main grate.  This is b/c the main grate is closer to the fire even though heat rises. 

I was pleasantly surprise to get the hearth stone above 1000F.  I can lower that temp by (theorectically) increasing the thickness of the hearth and/or lower the overall temp of the Primo.  So knowing I can get hearth temps that high solves one problem I had, which was not getting high enough temps in the Primo to begin with. 

My 2nd issue is to get reflective heat off the top stone.  A high enough temp to brown the top evenly preferably at the same rate as the bottom.  If I can achieve that then I won't have to buy a WFO. 

Convection, in this equation is about rising hot air.  You want to get as much hot air contacting the ceiling as possible.  Those poorly conductive, thermally massive bricks are gumming up the works.  Whatever you don't need for supporting the ceiling, get rid of.  In fact, if you can get 1" wide kiln stands and completely remove the bricks from the equation, you'd  be better off.

You MAY be right about this but I'll have to do some more test to know.  Though those bricks are massive and poor conductors they do serve the purpose of directing the hot air to the ceiling, if I leave a gap all the way around the stone.  I envision their purpose as walls for trapping/condensing that hot air right under the top stone.  I'm trying to create a mini oven within my larger oven.  I'm thinking that if I remove the walls, the hot air that rises will just dissipate into the larger dome of the Primo.  Now I can get dome temps to reach 700? but I need the temp right above the pizza to be 850? to brown quickly.  Again the hearth temp issue has been solved, just need to work out the heat issue for above the pie.  I'll try it without the walls in several days time and compare the differences. 

In the meantime, on to today's experimental set up and pies.

[Jackie Tran]

OK, so I created a new setup with a thicker hearth.  The idea is to lower the temps to around 800F or so instead of the 1000F I got with the first set up.

The 2nd change I made was that I allowed for a bigger gap around most of the bottom stone to allow more hot air into the oven chamber.  I'm still keeping the walls of the mini oven up with the purpose of trapping the rising hot air slowling it's dissapation into the larger upper dome of the oven.

3rd change I made was to add a pizza pan to the ceiling and a few bricks.  The idea is to help the ceiling reflect more heat.  With the first setup some of the rising heat was transferring through the 3/4" stone above thus defeating one of my intended goals of getting the temp above the pie to 850F. 

I also tried to place the lump coal in a U shape pattern towards the back of the Primo Firebox to hopefully influence the way the flames would rise.  I want their to be more flames and heat to the perimeter rather than straight up the middle.  Remember, I no longer having issues getting the hearth temps up.  I can reliably get hearth temps up to 950+.  As a matter of fact, it's too much heat.  I never imagine with I would have an issue with too high of a hearth temp.   

So here's the new set up. The distance between the hearth and the ceiling is now 2.5"+.  The hearth is about 1.75" thick. 

Last pic shows the direction of smoke (and ultimately heat) travel.  From the back to the front.

[Jackie Tran]

Ok so here are the pies of attempt #2.

Pie #1 was a NY'er.  Loaded with a stone temp of 950F.  Higher than I wanted but went ahead for the sake of learning.  I was suprised at the hearth temp as I was looking for a lower temp of 850.  I suspect that the hearth temp still got really high despite me thickening up the hearth b/c of the gap I create around the back end for hot air to rise into the cooking chamber.

Bottom was done within 20secs or so, so i slipped the pie onto a perforated pan to brown the top.  The bottom continued cooking through the pan and ended up burning a bit.  Not sure about total cook time but definitely under 2 mins.  This pie had a lot of oven spring and tasted a lot like the first NY'er done a couple of days ago.  I also noted some nice leoparding on the rim that seems so elusive to me.

[Jackie Tran]

Pie #2 is almost a nearlypolitan.  It's a nearlypolitan wannabe.   Loaded with a stone temp of 950, bottom was done in 20secs.  Again placed a pan underneath while top was finished in under 2 min total.

Got a small amount of leoparding on the rim but nothing to write home about. 

This whole caputo business has been kicking my @ss.  I'm about to give up on it.   

[Jackie Tran]

Pie #3 was a NY'er as well.  Same recipe as pie #1, except different cold fermentation length, hand kneaded instead of using the food processor, and baked at a lower temp.  This gave me a completely different pie.

This one was loaded at a stone temp of 800F.  Bottom was done in 30-40sec and then panned to finish top.   The crumb structure on this one was more breadlike and the outter crust was crispier like an American pie rather than a NY like pie#1.  Pie #1 had a spongier feel to it. 

This pie was the favorited among the 3. This crust was close to the perfect crust I had experience a couple of months back.

[Jackie Tran]

So things I would do different for the next time.  Maybe thicken up the hearth a bit more but replacing the thin pampered chef stone with my thicker primo stone. 

Lower the overall temp of the Primo from 700F+ to maybe 600F to get a hearth temp of 800F.

Consider doing away with the walls just to see if Scott123 is correct. 

Get a damn caputo apron. 

[shuboyje]

First I would burn wood chunks in place of charcoal, I think the open flame would really help the top stone.  Secondly I would set it up almost like a French bread oven with the fire box on the bottom and forcing the open flame into the "oven" and then out.

[shuboyje]

This is the type of oven I was reffering to.

<a href="http://www.youtube.com/watch?v=u4RiJs1a92U" target="_blank" class="aeva_link bbc_link new_win">http://www.youtube.com/watch?v=u4RiJs1a92U</a>

[Jackie Tran]

First I would burn wood chunks in place of charcoal, I think the open flame would really help the top stone.  Secondly I would set it up almost like a French bread oven with the fire box on the bottom and forcing the open flame into the "oven" and then out.

I have tried burning oak wood and it doesn't work as well.  First you have to burn the oak down to a coal/ash state anyway to drive off the smoke.  Then it really isn't hotter than burning lump coal to begin with.

While burning the wood, if you open the top, then it burns faster b/c it has more oxygen feeding it.  If you close the top lid (and keep the top vent open) it extinguishes the flame and you get massive smoking slowing down the burn of the wood.  Temps take longer to peak.  This oven isn't designed to burn wood like a WFO is.   You can use wood for adding smoke to foods like bbq, but not as a primary fuel source.  I'm not saying you can't burn wood, it's just not as efficient as lump coal.  And incase you didn't know, lump coal is made from hardwoods like oak, mesquite and such.  

I suspect one could even burn lump coal in a WFO very successfully and efficiently.  You could probably reach max temps quicker than burning wood in a WFO.  This is speculation on my part as I don't have a WFO to play around with.
But I should say that buring wood is probably less expensive than burning lump coal in a WFO.

[Jackie Tran]

This is the type of oven I was reffering to.
http://www.youtube.com/watch?v=u4RiJs1a92U

shuboyje, that is a very cool video.  Thanks for posting that. 

[Jackie Tran]

Tried a slightly new set up today with some decent results.  Took Scott's suggestion of removing the back wall.   Switched out the hearth with firebricks (FB) instead of my Primo stone (PS) since the firebricks don't tend to get as hot.  The FB hearth reaches 850 instead of 1000 with the PS when the oven is at it's max temp, which is a dome temp of 650.

Without the back wall I expected the back rim to toast faster but that wasn't the case.  The fire was leaning towards the left so the left rim was darkening quicker.  Still had to rotate the pie as before to achieve uniform browning of the rim.  This basically confirmed my initial thoughts that the walls direct heat to the the pizza stone and the gap b/t the wall and stone could be used to darken the rim.

I will retest again putting up the back wall again and keep the FB hearth.  I'll put my PS under the firebricks to thicken up the whole floor and see if I can't get a temp of 800 instead of 850.  850 was still a little too hot as I had to slide a metal pizza pan under a couple of pies today to prevent over cooking the bottom.   

So what's a post without pics right?  Here's the set up and here's a pie from todays bake.  had a nice wood fired taste to it.