Dutch Oven vs. Lava Rocks?
I’ve been using a cast iron combo cooker and it’s given me good results on the crust and such, but I’ve been wondering about lava rocks and would like to know if anyone has tried both Dutch oven and lava rocks. Is there much of a difference in the results of one over the other?
Obviously, I’d like to stick with the combo cooker as lava rocks sound like a lot of trouble: set up a baking stone, get those rocks into an aluminum pan and into the oven, etc. It also sounds dangerous (pour hot boiling water over super hot rocks? Yikes!).
I would give the rocks a try, however, if the results are markedly better.
One thing I’m wondering about—The rocks need to be sterilized in boiling water, in the oven, for 30 minutes before using. This is going to sound paranoid but...
(1) What pot do you boil them in, given that they can scratch up pots, and won’t that pot get contaminated by the toxins you’re boiling out?
(2) If you boil them in something like an aluminum pan (which can be thrown out)....doesn’t the steam containing the toxins you’re boiling out contaminate the oven?
Try to ignore stuff that doesn't make sense. And question everything. If you can't do the experiment that proves the case, then assume it is not true. Ten minutes at 200°C for your lava rock does more than any amount of boiling will and you do it every time you use them so just shake off the dust and put them in the pan.
Sylvia's towel trick is used by many to make steam with excellent success, but do take care when dealing with hot water.
As for combo cooker vs quarry tile or a ceramic stone (or a metal plate for that matter), the combo cooker does great for relatively small boules but I don't know how you do a baguette in a Dutch oven. So they are for different things.
I've no idea why certain sites/people say to boil the rocks before using...I assumed to rid them of contaminates that heat alone wouldn't get rid of.
And right now I'm just making small boules. If I decide to tackle baguettes, I'll certainly come back to this question of lava rocks and baking stones.
I've used both and prefer the DO method to oven steaming (using lava rocks).
There are two things that can help with lava-rock oven steaming. Get the steam source as hot as possible, so add some heat-retention material (like a piece of heavy link chain) to the lava rock container. Pre-heat at highest oven temperature for aat least 30 min before lowering the temperature and beginning the bake
A second suggestion is to cover your loaf with a metal roasting lid during the initial bake time. The goal is to trap the steam in close contact with the loaf for the first 5 - 10 minutes of the bake. Most of the steam will be generated from within the loaf. A high-hydration recipe works best.
That said, my choice remains the DO. Convenient and reliable results. I use three sizes/shapes for large/small boules, and for batards. I rely on oven-steaming only when baking multiple loafs or for unusual loaf shapes.
I'd glad you said that as it's so much easier than working with the many moving parts of lava rocks—and given that I have a small oven, a much better fit for me. But could you tell me a little more why you prefer the dutch oven? I was under the possibly mistaken impression that lava rocks/baking stone combo makes for a thinner, snappier crust.
In addition to being easier to work with the DO makes a crust better to my liking. Primarily a matter of enveloping the loaf in steam during its initial minutes of baking. Commercial ovens can do this with periodic steam injection. Home ovens try to achieve this with a constant source of steam from (say) lava rocks. Not nearly as effective.
I'd mentioned the concept, but hadn't read much or made a decision to buy (and didn't yet have a CO DO). My husband brought home a small bag, soaked them several times to remove any dust or surface contaminants, then boiled in an old pot he uses for various projects. He later said this prep was because of production dust, dye, and possible contaminants like mold spores. He used to be a Haz Mat consultant. There's never been an odor when baked. I fill old scratched heavy-duty loaf pans 2/3 full, pre-heat, add boiling water or soaked towels. The "heavy pieces of metal in a big roaster" is a nice idea, but too heavy & large for me to lift & store. Haven't done a side-by-side test vs. my Combo cooker; I use whichever pops into my head.
There are a lot of factors in play when you try to make steam. Some time ago I did a little piece for my own edification which you can find here. It deals with more than just steam, but steam is one element of managing the delivery of heat to the dough.
Based on your scholarly conjectures I have a couple of questions:
1. When baking with a Dutch Oven the steam is trapped within, so I think it makes sense to speed up the baking process by using the convection feature of my oven. No steam loss due to the oven fan. Make sense?
2. When baking on a stone with a steam-generator underneath I place a tightly sealed lid over the loaf to retain the steam generated from within the loaf. But this also prevents the steam from the oven steam-generator from coming in contact with the loaf. Would it be better to cover the loaf with the lid only partially and allow some oven steam to enter? How large an opening for this purpose so that the steam generated from with the loaf does not escape?
Thanks
It would be an interesting analysis to look at the relative contribution of radiation and convection to the total energy deposited in the dough. As the oven walls get hotter, the radiation component scales (roughly) by the fourth power of the wall temperature while the convection contribution goes up linearly with temperature. A dark/rough cast iron surface on the DO (vs a polished aluminum surface) drives up the emissivity and can make perhpaps a 20-40% difference for the radiation term. So turning on the convection won't hurt and may help.
When baking on a stone with a steam generator, you generally want the steam generator to be above the stone not below it since the steam will tend to cool off the stone if below. As for whether you want to put a dome over the bread or not, I don't immediately know the answer. I suspect that you want to use either a dome or a steam generator but not both together, and any cover is likely to be aluminum and thus reflective and so reduce the radiation contribution to heating the dough. One advantage to using a steam generator is that it gives you lots of steam early in the bake when you need it to quickly gelatinize the surface starch by condensation of steam. If you use a cover to capture the water being given off by the dough, it will be late to need though the evidence is that it works.
Also, an electric oven works better than a gas oven with a steam generator since the gas oven vents continuously and thus flushes out the steam very effectively. The only way I know of to deal with that is to preheat to a higher temperature than you might otherwise attempt, then shut off the gas for a few minutes after you load the bread and plug the vent so that you contain the steam. Five minutes is probably enough, but you are stuck with a gas oven. For an electric oven, check the seals and see if you can figure out a way to improve them, and some extra thermal mass in the oven can help deliver more heat while the steam generator is operating.
Well, that certainly helps to answer my question. I have an old gas oven. Heat rises from the bottom and that is all you're gonna get. No fan, no alternatives. ;-) I will say that I have successfully used steam for a yeast bread (made with packaged yeast). The aluminum pan was down on the bottom third of the oven, baking stone in the center; boiling water poured into the pan—that sort of recipe. But I know that's a different ballgame from sourdough made with a starter and all.
Kristen, from fullproofbaking places the rocks to one side and the stone with the loaf, slightly to the other side. Then she covers the loaf with a large pan that extends to the side of the stones. This way, the steam that goes up from the stones gets trapped in the pan covering the loaf. But this requires a larger oven than the one I have. You can see what I am talking about here:
https://youtu.be/VU1YHfldTtQ