The Fresh Loaf

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Oven floor is too cool

chester52101's picture
chester52101

Oven floor is too cool

Hello

 

I built a Allen Scott oven and have had a couple pizza parties, cooking about 25 pizzas in 2 1/2 hours. Oven temp was anywhere from 500-900 degrees. I baked pizzas with a small fire on the sides and back of the oven while pizza baked. Pizzas took about 4 minutes but the bottom of the dough was not getting crispy like it does in my conventional oven with a pizza stone…(The pizza tops at this point were on the verge of being burnt)

Any suggestions?

Mini Oven's picture
Mini Oven

you build it?  Has the floor had enough time to dry out completely?    

How long are you letting the oven "soak" with heat before baking?

chester52101's picture
chester52101

I built it a year ago and I started the fire around noon and started baking at 5.

SCChris's picture
SCChris

Under the deck, the oven floor, and is it of a sufficient quality? 

The under deck area of ovens can really suck the heat out of the deck.

 

Chris

BobSponge's picture
BobSponge

In those times where I want to bake pizza for an extended period like 2.5 hrs, I normally have to rake the coals back over the floor and let it reheat maybe a couple times.  Its a pain, but the only way I've found to keep the floor at pizza temp.

I have a Forno Bravo oven, heats up for pizza in about 2hrs.  Floor gets up over 1000 degrees.  I rake back the fire, and it cools to 850 or so in about 20 minutes.  About an hour and a few pizzas later its down in the 750 range.   At end of evening I rake remaining coals evenly over the floor close the door and in the morning its around 575.

 

 

chester52101's picture
chester52101

The floor of the oven-per directions- has 41/2 inches of concrete/ vermiculite mixture and another few inches of concrete, then firebrick.

 

Bob Sponge thank you for the time line- It should give me an idea of what to look for next time.

SCChris's picture
SCChris

I don't know how many large fires your oven has had, but what I can tell you is that the oven will get better over the first 10 - 15 real firings.  The insulation, vermicrete, will work but not nearly as well as more modern rigid board insulators.  These modern, space age, insulators are many times more efficient and come in 4X8 and smaller sheets of varying thicknesses and densities, and yes they cost more upfront.  Anyway you will loose heat out the bottom of the oven, all of our ovens do.  It's just a question of degrees, pardon the pun.  In my opinion, most wood fired ovens don't have nearly enough insulation anywhere around the oven. 

My suggestion is to use the oven and see if it performs acceptably.  If you find that the low deck heat is a insurmountable problem, you may be able to pull your deck bricks and add 1-2 inches of rigid insulation and replace the floor.

 

Chris

 

chester52101's picture
chester52101

Holy Cow those rigid boards are expensive! Thanks for the suggestions Chris!

Chad

SCChris's picture
SCChris

Sorry Chester, If you can afford it, and your going to use the oven "often", and if rigid insulation is available to you, and if you even can retrofit, it will pay for itself, by decreasing the fuel you use and stretching the baking and cooking window. 

For example; if the sweet spot for your hearth loaves is 450-525 and the oven looses 5 degrees per hour, you either have a huge window to bake a load or better still you have a huge window to bake multiple loads before re-firing.  At lower temperatures, the hourly rate of temperature drop of any oven will slow significantly and insulation will help.  A pork shoulder roasted at low temp for long hours is a beautiful thing! 

If you only intend to use the oven a few times a month, the rigid insulation may not ever, financially, pay for itself.

 

C

chester52101's picture
chester52101

You have convinced me!

 

SCChris's picture
SCChris

The first 10 - 15 firings will change how "your oven" behaves and you will get to know this personality and be able to predict things like how much wood to burn and how much time to burn to get your oven saturated for use.

 

Enjoy!!

Chris