How hot can a standard gas oven get?

[PapaJon]

Hello all, I've been browsing a while but never posted till now.  I love the passion I see here and look forward to improving my pizza making by joining such a knowledgeable community as this.

I have a question regarding my home oven which is a standard gas oven and apparently a bit old as I couldn't find "Hollywood by Gaffer & Sattler" anywhere online other than antique and repair places.  It has no cleaning cycle but the temperature probe on this looks like it can be unclipped easily and strung outside the front of the oven through the door, theoretically sensing the outside temp and not the inside.  That got me thinking though, and before I get too silly, I was wondering if anyone could tell me how hot a standard gas oven could get if the temperature probe was bypassed?  I want to avoid the whole house fire thing business.  I know electric can really crank it up, but I wasn't able to find any information on gas ovens from my search attempts here.

TIA!

[scott123]

Papajon, the peak temperature that your oven can reach all boils down to the btus of the burner and the insulation of the oven. I would think that with an older oven, you probably pre-date a lot of the energy efficiency limitations, so there's probably a good chance that you can, without the thermostat kicking in, crank it up to 800+

As far as safety goes, it's not talked about much, but I think that there a few unwritten rules about oven mods.

1. If the oven is valuable/important to you and rendering it unusable would be a catastrophe, don't mod it. There's ways to mitigate the risk, but exceeding an oven's peak operating temp is always a risk.

2. The more extreme of a mod, the greater the risk to the oven.  Taking an oven with, say, a peak operating temp of 550 and pushing it to 600 is a LOT different than an oven made to handle 500 being pushed to 850. Oven mods generally favor NY style temps, while, for the most part, Neapolitan is geared more for WFOs. If you can, instead of decreasing baking times with higher temps, shorten them with more conductive stones, such as soapstone or steel plate.

3. Once the thermostat is removed from the picture, the only way of ascertaining the true temp of the oven/stone is an ir thermometer.

4. Have a reliable fire extinguisher on hand and a working smoke detector.  If your oven doesn't have a cleaning cycle, the first time you crank the heat up, it most likely will smoke like crazy.  It might be a good idea to temporarily turn the smoke detector off, but make sure to turn it back on after the smoke clears.  If the oven's dirty, you probably want to clean it first, as a really dirty oven might ignite at higher temps.

5. Don't work with a modded oven if you're distracted or tired.  You don't have to sit in front of it for every second while it pre-heats, but you need to be awake and alert.

As far as your particular situation goes, I'm a little concerned about the oven door stressing the thermostat wire and eventually causing it to fail.  I think you might be better off finding a way of isolating or insulating the thermostat inside the oven.

[Tscarborough]

Just light a bonfire in your living room, your home owner's insurance will take an equal view with modifying your kitchen oven.

Pizza cooks fine at normal oven temps so why risk your house and your life for something that is not needed.

[PapaJon]

Thanks for the excellent and detailed information Scott.  Exactly what I was looking for.

While I'm not inclined to do anything just yet, I appreciate the direct response to my question and also the caution and fair warnings which are also very important.  I'm actually a little surprised there isn't a sticky with such warnings in this forum.

I did shoot a couple pictures just to see what it would look like and see if it would actually stretch the distance.  The probe line is indeed long enough and the door will shut, however in regards to whether the added stress to the probe wire, and how extended stress might damage it is a whole other issue, especially when exposed to extreme heat.

[PapaJon]

Here is the probe strung out the door.

[PapaJon]

Well I finally found the answer to my question.  I had purchased an IR Thermometer a couple weeks ago but hadn't had a chance to bake anything until today.  It turns out the dial on my oven slightly understates itself.  In the top main chamber the reading I was able to get off my new 1" thick corderite stone after 1hr was around 730F and the temperature off my old stone in the broiler drawer at the bottom was around 770F.  This is with no mods including leaving the temperature prob in it's original location.

I baked 3 pies and got nice oven spring and crumb but the heat balance is obviously not right as the bottoms were a little too chard and coloring on the top was a bit light.

For the first pie I baked it in the main chamber for about 2.5 min and then after not seeing the top char I was looking for I transferred it to the broiler chamber for another 40 seconds hoping that since it was just below the oven flames that it would improve the top coloring some.  As I wasn't intending to use the broiler chamber I hadn't given much thought to the gap between the stone and the top of the broiler drawer which was a bit tight but was obviously too hot to change mid bake.  I did manage to get the pie in but regardless I didn't get much change other than probably adding more char to the bottom due to the hotter stone.

The 2nd and 3rd pie I did only in the top chamber hoping to dial in the bottom char.  I'll lower the stone in the broiler drawer next time and give that a try although only my old cheapo 14" stone will fit .

[PapaJon]

Oven Temp (722F in pic)

[PapaJon]

Broiler Drawer Temp 771F

[PapaJon]

Broiler pic

[PapaJon]

Broiler with 3rd pie being reheated.  I've dropped the stone height to the lowest setting.

[PapaJon]

These are all pictures of the first pie.  For the record it's an all IDY version of pftaylor's Pizza Raquel.  Dough was all hand mix/kneaded.  Sauce was my first attempt to make my own and I used La Velle peeled whole tomatoes with salt to taste.  I removed as much seeds as i could and also strained out some of the liquid then crushed as best as I could by hand (A mixer and a boat motor blender are on my wish list).  The cheese is frozen costco grated cheese.  The pies were cooked directly on the stone and the screen you see in the pictures was used to help cool the pies.

[PapaJon]

Is there a temperature that Aluminum Foil will break down at?  I was wondering if it would be safe to wrap the bottom of my oven with foil to try and reflect more of broiler heat back down.  Also potentially remove the top cover/shield of the flame unit and cover it with foil and re-attach.  My next attempt at pizza I would start off trying in the broiler drawer.  Below are a couple pictures of my oven with the bottom removed and the flame unit exposed.  The flames would be on bottom side of the shield you see in the third picture.

[dmaxdmax]

Call me a noob, a sissy or appropriately risk-averse but I'm with Tscar'h.

[scott123]

PapaJon, although the burned bottom is a bit of a bummer, you definitely have a lot to celebrate.  That's great that you were able to obtain an IR thermometer. I'm also very impressed with your oven spring/crumb. All that's left is evening out the top heat with the bottom.

I wouldn't mess with aluminum foil nor would I utilize the broiler compartment.  Aluminum melts around 1100 f, and although you probably won't hit that in your oven, it is hottest close to the broiler and I wouldn't take the chance, especially since, if you've got the right setup, you shouldn't need to.

I'm pretty sure your answer will be an oven within an oven.  Leave the cordierite where it is, and, on the shelf above it, lay down quarry tiles, a large pan or the second stone surrounded by foil. Here's a few things to keep in mind:

1. Isolate the bottom of the oven by covering as much of the shelf as possible, so the heat coming up from the bottom burner collects on your makeshift ceiling, rather than leaking to the top of the oven.

2. Thermal mass will probably help, but it may not be critical.  If you can cover the entire shelf with quarry tiles, that's good, but you might be able to get away with just foil. As far as the materials go, conductivity doesn't make a big difference when it comes to radiation, so poorly conductive materials like quarry tiles or firebrick splits will work fine.

3. The darker the ceiling, the better.  If you go with quarry tiles or firebrick splits, try to get dark ones, as they'll radiate heat better.

4. Proximity of the ceiling to the pie is critical. The closer the ceiling, the better the top of the pizza will brown. 4-5" should probably do it.  It might be a little cramped when working with a peel, but it has to be that close for the radiant energy emanating from the ceiling to have enough impact.


That's how to correct your top heat issue.  As far as the cordierite hearth goes... although the Raquel recipe has evolved over the years, I think your best bet is to shoot for a Neo-NY bake time. With cordierite... I'm thinking 625 might be just about right for a 3-4 minute bake time

Summing up, build a relatively air tight ceiling 4" above your cordierite hearth, preheat the hearth to 625, and, while the pizza is baking,  have the gas flame going at full blast, so the heat collects in your manufactured headspace and bounces back on the pie.

[PapaJon]

Thanks for the detailed response Scott, and for the kind words.  Although the oven knob is rather worn and hard to discern it looks like it reads 550F then Broil.  The temps and subsequent bake I did yesterday were with the knob turned as far as it would go, or what I think reads broil.  The temperature probe/thermostat did shut off the oven at some point so I hope that means turning the knob less will indeed reduce the temperature (after reading temps of 700+ I'm not sure what to expect from this oven).  I will try to shoot for 625F next time, if for nothing less so that I can see what I can do at lower temps which I will most likely encounter when trying to bake a friends' houses.

I wonder what your thoughts would be about setting the corderite directly on the oven floor and not on a rack.  My issue is that my oven only has one rack and I'm not sure where I'd find another one which I would need to create the oven-in-a-oven ceiling you are suggesting. 

My two concerns are:
1) There is a slight possibility my stone might block some of the ventilation holes you see in the above pictures that are located along the edges of the oven floor.  The left and right side would be fine, but without checking I can not tell if my stone would fit perfectly in between the front and back rows, or if it would cover one row or the other.  If it does cover some holes, I might be able to set the stone at a slight angle so that the bare minimum of holes are covered if any, or I could put some regular bricks below the cordierite so that it is not sitting directly on the floor and the holes could vent.

2) I have no idea how much weight the floor can hold.  I know it feels solid enough and that it could definitely hold the stone at regular temps, but does that mean at higher temps that would hold true as well?

[scott123]

A single oven rack? Wow, that is a bit of a wrench in the works. Here's a few options

1. Rest the cordierite stone on 4 kiln posts which are each sitting on the floor.

http://www.axner.com/cordieritepost-3x1-12x1-12square.aspx

Any ceramic supply store will carry these. The downside is that, rather than the weight of the stone sitting evenly on the floor, it will be concentrated on these 4 points. If you do go this route, make sure the posts are close to the edges (on the 18" dimension) and/or corners, away from where the pizza is being baked, as they'll insulate the stone and create cool points for the pizza baking above.

Regarding the strength of your oven floor... steel doesn't lose much, if any, strength at the temperatures you're working with.

2. Fashion a makeshift shelf out of flat steel rods or angle iron.  Home depot has flat steel rods that can be cut with a hacksaw and rested on the shelf lips on both sides of the oven. An old bed frame (angle iron) can be cut and rested on the lips as well. Since the cordierite is one piece, you could use two pieces of angle iron (facing each other) to suspend that. I would probably wire the whole thing together so the stone doesn't slip and fall off the lip of the angle iron.

3. Buy a sheet pan that's larger than the interior of the oven and cut it down to the dimensions of the shelf and use that as the ceiling. It's a lot of cutting, but if it's an aluminum pan, it shouldn't take that much work.


No matter what way you do it, you really want the cordierite stone lifted off the floor, though.  If it's in direct contact with the floor, it will most likely heat up too much during the bake and you definitely don't want to cover any holes.

[PapaJon]

I do still have the scrap (16" x 2" x 1") piece I had cut off when I had my 18"sq stone customized to 18" x 16" x 1".  To pull a quote from a previous response from you regarding my stone questions, Scott you seem to be uncannily prophetic.

Wow, 18 x 18 x 1 with a cut for $29, that's fantastic.  That's also a great idea on keeping the 2" piece.  Trust me, you'll eventually need it.

I'm wishing I'd kept the scrap 18" long, but instead I had them chop 2" off it so I could increase the width of my stone if/when I wanted a wider baking surface for who knows what, french baguettes?.  Anyways, I bet if I scored the scrap with a file in the middle I could break it in half to get two 8" x 2" x 1" pieces.  If I laid them flat and put them on the far right and left sides I could rest the main stone on those and not block any of the vent holes.  Using the scrap and laying it flat would also have the advantage of having more surface area to diffuse the weight of the main stone.  What do you think?

I do like your idea of cutting an oversize backing pan down to size, but wouldn't that go against your concept of darker colors radiating heat better?   

[scott123]

Well, I was kind of hoping, since you mentioned that your oven could fit an 18 x 18 stone, that eventually you'd add the extra piece back and make 17-18" pies, but if you want to break it in half, sure, it's worth a shot.

I would suggest taking lots of temp readings- on all parts of the stone and ceiling before and after baking, to make sure it's pre-heated evenly.  As you get that close to the heat source, it might have hot spots. Maybe. These tight quarters- the proximity of the heat source to the hearth and ceiling, that might end up being beneficial.  We won't know until you try. At a minimum, it should give you faster pre-heats.

As far as the shiny pan goes... because of the bottom heat source, we're basically talking about Big Green Egg/MBE/Grill workarounds here. Bouncing the heat with something shiny (like foil or a shiny pan) is less preferable than radiating heat from something thick and dark, but it still might work. As it is, whatever tiles or bricks you might get, they won't cover the complete shelf, so you're still probably going to need some aluminum foil to fill in the gaps and help collect the heat.

[PapaJon]

Well, I was kind of hoping, since you mentioned that your oven could fit an 18 x 18 stone, that eventually you'd add the extra piece back and make 17-18" pies, but if you want to break it in half, sure, it's worth a shot.

Ahh, I see.  Well to clarify, my oven will fit an 18 x 18 stone, but just barely (it's 18-19" deep, front to back).  The reason I cut the stone to 18 x 16 was to ensure a 1" gap around the stone so I would get proper heat convection (even though not a convection oven).  I thought that this was important, but if it wasn't, I may have cut my stone for no good reason at all 

I did browse a restaurant supply store during my lunch, well maybe browse is a slight misnomer as I actually bought a an item or two or three...    (16" screen, dough scraper, & a 18" x 20" - 42"long peel.  All for $16.43), and they had a 18" x 26" aluminum sheet pan for $8.59, or a 17" x 25" "Icing/Cooling rack" for $6.59.  I will need to measure the exact width of my oven again to make sure, but either of those might work.  They also had a 17" Dia. "work cover" for $8.89 which seemed like another option although that would kind of go against the "heat convection" theory right? 

[scott123]

I hate to tell you, but you cut your stone for no good reason at all    You run into the 'make sure there's room on every side for air flow' advice quite a bit in different food forums. Unfortunately, it's totally bunk. As long as there's room on two of four sides (by the left and right walls) there's plenty of air flow. I always tell people to buy a square stone with room on the sides, but is almost touching the back wall and front door. If you haven't already broken your extra piece in half, wedge it between the stone and the back wall. If you put it by the back wall it won't go anywhere. And as long as it's centered, the missing 2 inches should make no difference because of the roundness of the pizza.

That icing rack for $7 looks perfect.  Just hack off the extra length (through the two outer supports) and you should be good to go.  Since quarry tiles are lighter (and generally darker), I'd go with those.  If it were me, I might even consider using regular black glazed bathroom tiles, since they won't be in contact with the food. Maybe. I might talk to the guy at home depot first about lead in the glaze.

P.S. I'm not a big fan of screens because they insulate the crust and extend the baking time, but if you're dead set on using one, increase the pre-heat of the stone another 50 or so degrees.