Karangi Dude's 48inch Oven

[Saluki]

Re: Karangi Dude's 48inch Oven

As someone just starting to research the process, thanks is advance for the insightful thread.

Great Thread - Great Pics - Great Inspiration

[Karangi Dude]

Re: Karangi Dude's 48inch Oven

Thanks Saluki,
That's the great thing about this forum people like to share there experience.
Like minded people with a common interest.

[arthuritus]

Re: Karangi Dude's 48inch Oven

Hi Doug,

Hoping to build my second oven soon. I'm considering whether to put an extra layer of thermal mass under my 75mm firebricks. The idea being that the additional thermal mass means that we should be able to cook more pizzas before raking the coals back to reheat hearth. However, going by the temperature readings you posted earlier, the bottom of the fire bricks were far from saturated anyway, so having more thermal mass to heat up would be a waste of time and fire wood. Have you done any more measurements now that you have been using your oven for ages?

[brickie in oz]

Re: Karangi Dude's 48inch Oven

Hi Doug,

Hoping to build my second oven soon. I'm considering whether to put an extra layer of thermal mass under my 75mm firebricks. The idea being that the additional thermal mass means that we should be able to cook more pizzas before raking the coals back to reheat hearth. However, going by the temperature readings you posted earlier, the bottom of the fire bricks were far from saturated anyway, so having more thermal mass to heat up would be a waste of time and fire wood. Have you done any more measurements now that you have been using your oven for ages?

I can do a whole pizza party with 80mm of floor mass with one rake over to reheat the floor.

More mass = more fuel+more time.

[arthuritus]

Re: Karangi Dude's 48inch Oven

How many pizzas is that? 90 seconds apiece or are you doing them at a lower temperature?

[brickie in oz]

Re: Karangi Dude's 48inch Oven

90 seconds to 2 minutes for the first few and the time drops as they go along.
We normally have 10 guests so average 1.5 pizzas per person, plus we do a sweet in the oven too.

[arthuritus]

Re: Karangi Dude's 48inch Oven

Ahh yeah that sounds about the same as mine I can only do a couple of 90 second pizzas before raking the coals across.

[david s]

Re: Karangi Dude's 48inch Oven

If you keep an active fire going while you cook the pizzas, the heat will be retained better in both the dome and the floor. It also provides an oven light. The flame needs to go right up the side of the dome. Pizzas cooked this way are much better IMO.

[arthuritus]

Re: Karangi Dude's 48inch Oven

Absolutely. Its nearly impossible to cook a 90 second pizza without an active fire, because the bottom gets cooked while the top is still raw. But the live fire only keeps the floor warm on the side the fire is on, which means you have to swap everything around periodically.

[Karangi Dude]

Re: Karangi Dude's 48inch Oven

Hi Art,

To answer your questions,

1. The standard thickness of the hearths of commercial pizza ovens in Sydney is only 50mm.
We tend to build our ovens for home use to be a little bit more versatile eg; for prolonged heat retention for cooking long after the fire has been extinguished, so I would say anything between 50mm and 75mm would be sufficient.

2. You must fire your oven at high temp for a long period of time to get the hearth to be somewhere near saturation.
But for pizza cooking you do not need to go to that length, to continue cooking 90 sec to 2 min pizzas you need to fire your oven until it burns off the carbon and then have a good supply of heat off to the side (lots of red hot coals) with some flame to lap over the top of the dome to continually heat the hearth where you are cooking and of course to cook the top of your pizzas.

3. I have ran many tests and monitored the temps, but without going into great lengths the results show basically what I have explained above.

Art, I suppose all ovens vary but with my oven I can continue cooking pizza as long as I like, I never have to rake hot coals over to recharge the hearth where I am cooking pizza, because I continually put small pieces of hard wood onto the fire so that flames are always lapping over the dome to the side that I am cooking on (a good thing about Igloo style ovens)
The other advantage is that the flames supply a good source of light.

I hope I have answered your questions

[arthuritus]

Re: Karangi Dude's 48inch Oven

That's enough to convince me I don't need more thermal mass. Thanks

[Karangi Dude]

Re: Karangi Dude's 48inch Oven

No worries Mate,

Art, I forgot to mention that good insulation under the hearth is probably more important than on the dome as the hearth is sitting an a solid slab that will wick the heat from the hearth. A hearth with good insulation will certainly heat up and retain heat if it is well insulated.
My ovens hearth sits on 75mm of insultating firebrick.
The one thing I always do is have the fire bang in the middle until the carbon burns off then I move the fire to the left side and let the oven rest for 30mins before I start to cook pizza, I normally start nearer to the righthand wall for the first few then just right of center from then on.

Art, there is one thing that I have noticed and that is the way my oven cools down after I put the insulated door on, it first equalises and then begings to cool from the inside, the outer side of the bricks remain hotter.
My take on this is the insulation stops the outside from cooling as there is no contact with the air, interesting to note!!!

[Karangi Dude]

Re: Karangi Dude's 48inch Oven

What a pitty I had to burn this beautiful timber but I had to make room for some good hardwood for my WFO.
I cut these camphor laurel trees down about three years ago they are a beautiful tree but they are classified as noxious weeds, they grow huge nothing to see them up to 6 feet in dia and up to 20 - 30 metres tall.
We had to cut down about 12 and this guy said to me could he have some of the bigger branches and trunks, so I held onto them for him but he never came to pick them up, I have held onto them long enough so they had to go (sorry to all the wood turners out there) they use this timber to make furniture and also for wood turning.
I started a good fire from a couple of old palletts and began burning the champor laurel, I cut it in lenghts that we could handle, it took 3 days to burn it all there was about 8-10 cubic metres.
Unfortunately this wood is not suitable to burn in our WFO or wood heater as it is high in champor oil and can clog up the flue with creosote.

cont;

[Karangi Dude]

Re: Karangi Dude's 48inch Oven

#176 cont;

You can see the grain in one of the pics it is a beautiful timber
But I got a good load of hardwood that I cut into 2 foot lengths then split into pieces about 5'' to 6'', there is stringy bark, spotted gum, flooded gum and some ironbark, I should be right now for winter as I also got a ute load of offcuts from the wood turning place that make handles for spades, axes etc. it is spotted gum about 2'' x 2'' x 2foot long great for getting the fire started.

[cobblerdave]

Re: Karangi Dude's 48inch Oven

Gudday Doug
Its a shame to see timber burn't off like that... but anything that the insects will not eat can't be good in an oven. A few year ago friends in Mulwoolamba payed to have the Camphor felled on thier property the company did a lot in that area and collected the larger logs into containers to be sent to china. Aparently there was a shortage of camphor wood to line camphor wood chests.

Regards Dave