The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Help with WFO

twodips's picture
twodips

Help with WFO

Good morning everyone,

I am new to the WFO scene and was looking for an oven that'd be versatile. I settled on a Mattone Barile Grande oven from Brickwood Ovens.

It's now built but I'm having issues getting it hot enough and maintaining heat. Where did I go wrong or what am I missing?

arlo's picture
arlo

I have a few years of production wood-fired oven experience, and my own in the works. From first glance your dome height seems a bit too high, and your door is rather large. Both things can result in heat loss and less than stellar performance for batch baking. Take a look at Alan Scott style brick ovens, their doors and dome height are a great reference.

 

Also, insulation and layers is a key as well to keeping heat in. Its hard to tell from the picture of size/thickness/et cetera. But those would be my first suggestions.

Mini Oven's picture
Mini Oven
mrvegemite's picture
mrvegemite

The chimney/flue should be separate from the chamber so heat doesn't escape directly up it when a door is on. Also agree with previous comments on door height and insulation.  It is hard to tell from this one angle but there seems to be a couple of things at fault with the design

Mini Oven's picture
Mini Oven

me was the door looks too high.  Got some dimensions and more detail?  It looks like there is no insulation on the front of wall of the oven.  Is the back wall the same? 

Checked here:  http://www.brickwoodovens.com/mattone-barile-grande

Looks like there are pieces missing to this oven puzzle.  Those drawings are not the best.  But I think with a second wall on the front lowering the door height and then blocking the chimney, you'll have it heating up better.

embth's picture
embth

What temperature have you trying to reach?  Does your oven have a door?  Is your wood good and dry?

twodips's picture
twodips

Ok, let me answer some questions first.

1. No there's no insulation on the front brick.

2. Yes, the rest of the oven is insulated. Floor is 6 inches thick, 3 of regular cement, 3 of portland cement and pearlite and of course the whole inside is firevbrick. Walls,roof and back are insulated with fiber blanket and 3 inches of stucco.

3.My wood is dry, oak and mesquite to be exact.

The oven interior measurements are: 26" wide, 18 1/2" high and 41" deep.

I've tried to reach 900 or even 850 but pull up short at about 650 and it won't hold it very long at all.

 

 

embth's picture
embth

When you are trying to keep 800 plus degrees, I assume you are planning pizza.   I think that is a bit hot myself and prefer to make pizza at about 750 degrees.  They cook very fast at that temp.  For bread, of course, you are looking for 450 to 500 tops.   So, to keep the oven hot for pizza means door is open and there is a moderate fire on one side of the oven with flames just "licking" over the inside of the dome.   For bread, you bring the oven up to about 550 to 600, clean out all the ashes and swab the oven floor with a damp rag or mop.  You then shut the oven door and let the heat "equalize" for 30 minutes or so.  Then check the temperature of the floor, dome, etc. with your laser thermometer and if it has cooled down to bread level,  load the loaves and close the door (and the damper too if you can).  Then you cross your fingers and wait….(all the while wishing somehow there could be a window into a brick oven).  Usually the bread bakes up fine….in about 16 to 20 minutes I give the loaves a quick check, moving them around if needed.  I have just come in from firing my oven for tomorrow's turkey.   Best of luck with your baking and your oven,   Embth

 

rgconner's picture
rgconner

There are glass blocks available that can resist those levels of temperature and could be fitted into the door.

Glass is a great insulator. 

embth's picture
embth

but it might make for a very heavy door.  Thanks for the info…I never considered heat resistant glass when building my oven.  I will just have to be content to wait 20 minutes before I get a look at how my breads are doing.                     Happy Thanksgiving to all!

Mini Oven's picture
Mini Oven

In order to trap burning heat in the oven (talking blocked chimney, open door) there has to be a minimum difference of 4 inches or 10 centimetres between the peak inside roof elevation and the top of the door opening.   

My learned baking oven builder/advisor has also stressed that the door and front wall is the greatest place for lost oven heat.  He encouraged me to take any left over fire bricks and thicken up the front wall extending the opening forward at least another brick thickness.  The opening and front wall then has more mass and cools slower once the oven is heated up to desired temperature and "soaked."  

twodips's picture
twodips

While having an ultra quick large pizza oven (950 deg) was what got me started on this project (yes, I was going for the Tim the Tool Man thing...grunt,grunt,grunt) I also realized that since I'm taking all the time/money to build this monster I really should have a more versatile oven. I really love baking bread and cooking, an am in Phoenix,AZ  I might as well have a large OUTDOOR space.

As a side note, my wife and son went to culinary school so I got a free education to boot which makes me real dangerous with a large oven!

Here's the big issue, the bottom line as it were. Now that this oven is built and it seems maybe a flawed design (depending on who you listen to) I need to figure out how to get it as close to a proper working Barrel Vault. I can wait a few minutes instead of 90 seconds for a pizza as long as I can bake bread,roast meats etc without using a whole cord of wood for each firing...

Hopefully I'm not asking for too much, thanks for all the help so far and HAPPY THANKSGIVING from a newbie!

twodips's picture
twodips

Sitting in my living room watching football and thinking of the monster outside, one thing that strikes me as odd. I've got a 6" chimney but the front of the oven is black with soot. This doesn't make sense as the chimney is "supposed" to vent smoke before it gets out the front. 

Also, I wonder how far I can cut the entry size down and 1. Still be usable for roasting foods and 2. Not choke out the oven. I could add firebrick behind the red brick facade to trim the opening size, maybe on a drystack or worst case mix a small batch of fireclay.

Mini Oven's picture
Mini Oven

My entire firebrick liner will be dry stacked bricks.  The only way to go in my mind.  The only mortar will be to fill in triangular cracks between bricks (inside corners touching) of angled dome bricks to support the position of those bricks.  Dry stacking is also easy to remove and repair.    

You can trim the three bricks above the door opening so they support themselves key stone style.  Here is one example using bricks 5 & 6 (same cut) and 7 as the key stone:     Points on bricks 5 & 6 should meet the walls to limit outward movement (or  notches can be cut into the bricks below them and bricks 5 & 6 left whole.)       

 

Your oven is taller so just ignore the row of bricks above them.   My bricks may be a different size also but I'm showing the self supporting arch.

The minimal opening is not worrisome as you still want it big enough to shove in a turkey, goat, small pig or whatever.  Folks building too small an opening are only interested in making pizza.   If you still have the bird around put it into your favourite roasting pan and measure it.   Or take a tape measure with you to the butcher or freezer section in the supermarket.  

Something else to ponder,  if at anytime you want the opening bigger, and you have put an extra dry stacked wall inside the existing one, plan it so you only have to add one brick on each side to raise the opening.  It goes to reason that in adding a row of brick on the sides, you will have to remove the row of brick between the opening bricks and the top of the oven. 

 

Randyj's picture
Randyj

You are probably to small on the chimney size. It would breath better at 8 ". Also if you could build your self a new door /wall behind the chimney that will help keep the heat in. You want about 63% the height of your oven in the opening.  I am not sure what to do about the lack of insulation.  That might be hard to fix. I will think about it. 

 

Randy 

The Bread Stone Ovens Company's picture
The Bread Stone...

Hi,

Just wanted to put my 2 cents in about the heat retention. Unfortunately sometimes it is how the oven is built/designed but you can add an insulated door which we make at our warehouse, we offer cast iron door as well, even insulation for the wall. 

Here is a link to read about the items we offer when you get a chance!

https://www.breadstoneovens.com/collections/oven-components

https://www.breadstoneovens.com/collections/cooking-tools

Let us know if you have more questions at info@Breadstoneovens.com