The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Baking Stone Pre-heat lag time

davidg618's picture
davidg618

Baking Stone Pre-heat lag time

My wife bought me an infrared remote thermometer for Christmas, and I've been using it much more than I expected. One thing I've noted: my baking stone, a Fibrament, lags behind my oven announcing it has reached temperature. At 500°F it lags by 25 minutes. Other make stones' lagtime will vary, but I suggest 30 min. from the time the oven air temperature has reached the set temperature is a reasonable rule of thumb. The guidance, "about 1 hour before loading preheat your oven and baking stone..." may or may not be quite enough. My oven, with the stone in, takes 40 mins. to reach 500°F.

David G

wayne on FLUKE's picture
wayne on FLUKE

Good info, thanks. I have the 15x20 Fibrament stone. Is that what you have also?

wayne

davidg618's picture
davidg618

Hi, Wayne,

I had them cut 3/4" off, so mine is 14-1/4" x 20"--otherwise, I'd have had to replace the glass everytime I closed the door;-)

David G

Yerffej's picture
Yerffej

David,

Your valuable information fits with my experience that, generally speaking, stones take at least an hour to heat up and even longer when dealing with very thick stones in commercial ovens.

Jeff

breadman_nz's picture
breadman_nz

Fibrament takes a long time to heat and has a fairly sluggish thermal transer rate (which is OK for bread, but not so good for fast-bake pizza).

Another option to consider in home ovens is cordierite or the other alumina stones (I have a 16"x16"x3/4" sillimanite kiln shelf).

When I do pizzas, with a 1/2" steel plate on the top shelf (providing broiler function) and the sillimanite stone to bake on, the oven takes around 2 hours to heat up properly.

breadman_nz's picture
breadman_nz

The stone stays well charged once hot... no worries about cool down time, and it's a 3-4 minute bake for a good NY-style pie.

varda's picture
varda

David, I preheat my oven for at least 40 minutes when I am using my stone which is a one foot square, one inch thick slab of Finnish granite.    If less than that the base of the  bread doesn't cook right.   If that or more, all's good.    My oven lists itself as preheated in 20 minutes or less depending on temperature.    If I'm in a bind, that is bread is proofed too early, I have learned it's better to get rid of the stone than use it too early.  -Varda

Elagins's picture
Elagins

There's a really good technical comparison of the two materials here: http://www.pizzamaking.com/forum/index.php?topic=5645.0

Stan Ginsberg
www.nybakers.com

Yerffej's picture
Yerffej

While I do not have first hand experience with granite, I have read of it cracking under thermal shock.

Jeff

varda's picture
varda

I think there are a lot of different varieties of granite.   I've been using this Finnish white stuff for 2 years in my gas oven, and as the floor of my WFO.   I got one crack in one of the blocks in the WFO two years ago, and I had to replace that stone.   But that could also have been due to weathering.    Regarding the thermal properties - don't know the theory.   Just know how to use it from experience.   -Varda