The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Top and Bottom heat

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Liverpoolbaker's picture
Liverpoolbaker

Top and Bottom heat

I'm wondering about top and bottom heat, and effects on oven spring.

As a self taught baker I just sort of worked out what I like, but I can't find much about it in books or on the internet. What settings do people use for their ovens, does increasing the bottom heat increase the spring? Can anyone point me in the way of some good articles or books that may cover this? Or is it one of those things you just figure out. 

Sam

CARLOS BARAJAS's picture
CARLOS BARAJAS

Nancy Silverton "La Brea Bakery Breads" is an excellent source. She recommends preheating oven at 500 degrees for an hour with a pizza stone on bottom of Your oven rack. After loading your loaf directly on the stone, reduce temperature to 475 degrees etc. etc. She gives a lot of details on the procedure, and I have always achieved Great Results.

Carlos

Mini Oven's picture
Mini Oven

is your oven instruction manual.   It helps spring to have the heat source predominantly under the loaf.

Other factors that figure in are the colour and material of the pans or baking surface, do they absorb heat or reflect it? Is the oven fan assisted and size of oven.

Liverpoolbaker's picture
Liverpoolbaker

Sorry guys, I should have made this a bit clearer. I was talking about deck ovens, I have a four deck Mono oven, with variable top and bottom heat. The instruction manual doesn't say much about what settings to use, but only recommends a bottom heat of 40 and top heat of 65, without explaining how it really works. I can't seem to find much literature about how to utilise these settings or how they work exactly. Just wondering if someone could point me in the right direction. 

Thanks. 

Mini Oven's picture
Mini Oven

(that ought to get some focus)  :)

ananda's picture
ananda

Hi Sam,

I think the key advice I can offer is to really think about the individual products you are baking when deciding on oven settings for your deck ovens.

Firstly, you may want to consider how long is the preferred baking time.   A short baking time demands a higher top heat setting.   So for sheets of bread rolls your top heat would be set at 80 [for Mono], or 8 [for Tom Chandley].   Bottom heat has to be lower, at say 50/5 [mono/chandley], otherwise the bottoms of the rolls will burn.   Bake time ideally would be no more than 10 minutes.   

Secondly, think about the surface area of the product relative to volume.   For rolls there is a large surface area to take colour,but  very small volume to penetrate in order for the starches and proteins to set and the product to be baked through.   So look in contrast at the example of a strap of panned loaves.   Here we have a small surface area relative to product volume.   The bottom heat has to penetrate through the metal of the pan and a long way into the loaf in order to bake out the very centre of that loaf.   So the bread has to be in the oven a lot longer, with a much higher bottom heat setting.   For Chandley ovens I bake panned loaves at 6 top and 8 bottom.

Thirdly, ovens will vary in output performance from manufacturer to manufacturer.   So the settings for a Chandley oven will differ to the Mono.   Why?   Because the baking surface in a Mono is thicker grade, so the heat retention is better.   Meaning you need to bake with lower bottom heat settings in a Mono than in a Chandley.   This is especially pertinent to "hearth-style" breads.   40% bottom heat in a Mono is the maximum I would use from experience; I prefer to be down at 35%.   But a Chandley I would go somewhere between 4 and 5.

And a constant when working the deck ovens:  be forever thankful that you have some solidity of heat thanks to the bottom heat conduction plus some radiated heat from the top.   Remember always that you could be baking with some smelly rack oven!

Finally, a couple of other concerns.   If the product has sugar, then heat settings need considerable reduction.   And, density will impact too.   Because more bottom heat will be required to bake out the loaf, so top heat will most likely need to be adjusted down in order to compensate for increased baking time.

Top heat colours your bread; bottom heat penetrates to the middle of your product in order to bake it out.

All good wishes

Andy

Liverpoolbaker's picture
Liverpoolbaker

Andy

Thank you very much, that's a great answer and just what I was looking for. We mainly bake hearth loaves directly on the deck, with a bottom heat of 40. I was wondering if I upped the bottom heat and dropped the top would it increase oven spring considerably?

Thanks

Sam

ananda's picture
ananda

Hi Sam,

The danger of increasing the bottom heat is you will end up burning the bottom of the loaf; especially with the Mono oven, as the oven floor is such a solid construction.

You may be better to concentrate on securing good steam supply to increase spring.   If you can keep the surface of the loaf moist for longer, then you should get better final volume.

Dropping the top heat will only mean your loaf takes less colour...so it will need longer in the oven, meaning burnt bottom, and drier crumb than necessary.

I use 60-65 top heat and 35 bottom heat for hearth loaves on a Mono oven if that's any more help.

Best wishes

Andy