The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

lava rocks? the kind you buy at home depot/lowes in the bbq/grilling section?

koloatree's picture

lava rocks? the kind you buy at home depot/lowes in the bbq/grilling section?


i plan on making a trip to the store tonight for lava rocks. its the plan lava rocks in the grilling/bbq section?

LindyD's picture

Yes, those are the ones.  Around three bucks a bag.  I put the excess in my garden.

DonD's picture

I bought mine at Lowe's in the grill/bbq section.


Pablo's picture

I'm wondering why to use lava rocks vs. plain old ordinary rocks.  I know lots of people do and there is no doubt a good reason, I'm just wondering what it is.  Thanks for any info.


Mini Oven's picture
Mini Oven

If you don't know what density you're dealing with. 

The thermal shock of pouring water onto hot rocks can be too much and they crack, sometimes with dangerous results.  Lava rocks are very porous and will not explode in this manner.  Filling a tray or pan with them will prevent spitting and splashing of water as it turns to steam on the pre-heated surface.  It is done for safety, not for surface area.

It goes to follow that the next question is how many lava rocks should be used?  Enough to cover the bottom of the pan so that no surface can be seen.


ehanner's picture

I hear the stories about clouds of steam generated by heating lava rocks in a pan and I am puzzled by the apparent contradiction. Lava rocks as available to the consumer at places like Home Centers are very light and porous. They are in fact expanded into a foam like structure with not much mass. Rocks or fire brick are a step in the right direction in that they would create more steam before they cooled to below boiling temperature.

I read an article written by Michel Suas of the sfbi where he discussed steaming in a home oven for a recipe he was sharing. His suggestion was to fill a pan with old hardware, nuts and bolts that would be heated to a high temperature and because the steel has great thermal mass would create great steam for a longer time than anything else with less thermal mass. This makes perfect sense to me. The surface area of all the individual pieces would make for a great steam generator.

The whole point of using steam is to create a thin moist layer on the surface of the dough during the initial phase of baking and the period where oven spring is occurring. According to Suas, "To achieve the greatest benefits from condensation,  steam should be injected into the oven before and after the loaves have been loaded". This tells me that even a brief period of dry heat will diminish the oven spring. Greater thermal mass would allow one to apply a small amount of hot water on one side before loading and again on the other side after loading.

I my experience, I try to add only the water that will evaporate in 10 minutes. For me that is no more than 1/2 cup of boiling water for the main steaming. Otherwise the loaf is being steamed after the crust has set and diminishes the color.


AnnaInMD's picture

baking pan be sufficient ?

ARCity's picture

I recently came across this "tutorial":

I've never tried it but it seems to produce a lot steam quickly, which is paramount. It's only within about the first minute that steam can be effective. I've tried a lot of other methods but this one looks the most promising.