Holding High Heat

[james]

I was asked the other day if it was a contradiction to say that the round Italian oven design was faster to heat up, and better at holding the high heat required for making great pizza than the thicker barrel vault oven. The question was based on the logic that what heats up faster would give up heat faster.

So, it is true? Does the Italian brick oven heat up faster, and retain high heat better? Yes. The round and thinner Italian oven design is able to sustain the higher heat (700F+) necessary for cooking pizza (or any other high heat cooking) because it is highly efficient at re-charging the oven floor and dome using the fire in the oven. With the Pompeii Oven and Forno Bravo oven, the mass of the dome and floor are filled with heat, and they are efficiently re-charged from the fire. With a high quality material in your dome and floor, you are able to sustain 700F cooking virtually indefinitely. It's a closed-loop system where the heat that food (and the oven opening) take out are equally refueled from the fire. That means no raking the coals over the cooking floor, or waiting for a period of firing while the dome heats back up. Can you imagine an Italian wood-fired pizzeria just stopping cooking during the dinner rush? No. It just doesn't happen.

You cannot maintain this high heat with the barrel vault oven. It is impossible from a physical world perspective. The problem is that the entire mass of the barrel vault dome or floor is never heated to 700F, so the heat from the fire is constantly migrating to the outer reaches of the dome and floor mass. As the outer reach of the dome mass heats up from 200F to 400F, the inside of the oven quickly falls from 700F to 400F. That's a good thing if you want to bake hundreds of loaves of bread at 400F, but it isn't good for a pizzeria, or a back yard pizza oven. In fact, it's incredibly frustrating.

So, is rapid heat up and better sustained high heat a contradiction? No. In fact, these are the characteristics that define a pizza oven.

I sometimes think I am the only person in the world with two working barrel vault ovens and an Italian pizza oven right next to each other. I see the differences every day, and they are not minor. The ovens are completely different -- other than the fact that they are wood fueled.

For folks looking into different basic designs, I hope this is helpful.

James

[mnlewis]

Wow, that is a mouth full, no pun intended. So with my oven, a barrel type with round front and back is going to work for us, it is the back yard personal non professional oven. What the wife and I do is start cooking on a friday and usually don't stop until sunday night unless we took a couple of days off. I have a smoker that I go through a bag of lump charcoal in about a day. Thats a large bag. When I saw the out door oven I said "Ive got to get me one of these" so away we went, researching, designing and now 1/2 finished with the brick work. My biggest thing was and really still is, how big to make the front opening? Right now I have it at 16" wide, haven't started the dome yet so I can adjust to fit!
The oven itself is 32" wide by 47" deep, inside demensions.
Any suggestions to how big to make the opening
Mark

[mylesonic]

Hi, well from what I've studied this is really a critical consideration. You need to make the opening about 62 percent of the height of the vault of you oven. That is, the highest point of your oven chamber being 100 percent, the door opening should be around 62 percent of this height. I believe it's a pretty standard ratio derived from studying ancient ovens and measuring the average of some older and truly efficient ovens. As for the width of the door way, I'm not as certain...

[Robert Musa]

Originally Posted by mnlewis

Any suggestions to how big to make the opening
Mark

IMHO, err on the side of making it wider. i've often wished mine were just a little bit wider from the standpoint of:

1. friends gathering around the oven on a winter night, being able to see and feel the heat and food, and

2. greater ease in manuevering multiple pizzas and dishes.

if you find that you've made it too wide you can always go back, ala the Cask of Amontillado, and wall it up. on the other hand, you'll never be able to make it wider after the fact.

[james]

Hello all,

I decided to make a sticky posting on oven opening sizes. It gets asked a lot, so it will always be there. Robert, how large is your opening?

http://fornobravo.com/forum/showthread.php?t=692

James

[Robert Musa]

Originally Posted by james

Hello all,

I decided to make a sticky posting on oven opening sizes. It gets asked a lot, so it will always be there. Robert, how large is your opening?

http://fornobravo.com/forum/showthread.php?t=692

James

measured it this morning, it's 18 inches. the "tunnel" to the oven is 17 inches long.

[james]

Robert,

You can definitely make the vent landing space easier to work with (next time).

1. You can make it wider
2. You can angle the bricks that support the vent outward
3. You can attach the vent to the enclosure, and make the vent landing and oven landing into a single piece.

Check out our oven anatony graphics see see how wide the Premio arch and landing its. It's roughly 36"W x 24" deep, and works as both the vent landing and oven landing.

Here are a couple of graphics on the closed and open vent design.

James