This month in our Baking Club, we're working our way through Peter Reinhart's The Bread Baker's Apprentice by baking bread—lots of it. So far, we're learning as much from the master bread baker's tome as we are from each other. With more than 15,000 members, there are quite a few very experienced bread bakers in our ranks. This week, one of them taught us a smart trick for creating steam in our ovens. (Hint: It involves rocks.)
When Paige Weisskirch shared her experience making the book's Basic Sourdough Bread with the Club, she casually mentioned substituting Reinhart's instructions for hearth baking with "the lava rocks in a pie tin method."
"It’s a method I’ve used in the past with excellent results every time. Besides, I went through the bother of stealing lava rocks from my neighbor’s yard. Wasting them would be unethical." (Editors' note: We'd like to point out that lava rocks are available from hardware stores and garden centers.)
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The comments erupted in a chorus requesting more information on these lava rocks. Weisskirch pointed us to a Cook's Illustrated article that explains it. And, for those of us who are newer to bread-baking, it helpfully details why we'd want to go to the trouble of making steam in our ovens in the first place:
For starters, a moist environment transfers heat more rapidly than dry heat does, allowing the gases inside the loaf to rapidly expand in the first few minutes of baking, ensuring maximum volume. At the same time, steam prevents the bread’s exterior from drying out too quickly, which would create a rigid structure that limits rise. Finally, moisture converts the exterior starches into a thin coating of gel that eventually results in the glossy, crackly crust that is a hallmark of a great artisanal loaf.
Cook's Illustrated notes that the usual recommendation for creating steam is to preheat a pan on the oven's bottom rack and pour boiling water into it, the downside of that method though is that the water doesn't continue to boil for very long and thus, doesn't create all that much steam.
Inspired by the superheated stones used to generate steam in Swedish saunas, Cook's Illustrated came up with another approach using lava rocks, explaining: "These irregularly shaped rocks have a lot of surface area for absorbing and retaining heat, maximizing the amount of steam produced when boiling water is introduced."
To try it out yourself, place lava rocks in a wide pan on the bottom rack in your oven and preheat. (Weisskirch uses a couple of aluminum pie pans stacked together, which is both cost-effective and eliminates any worry of scratches on a nice pan.) When your bread is ready to bake, pour a small amount of boiling water (about 1/4 cup) on the rocks, close the oven door, and let them steam for about a minute. Then, put your bread in the oven, pour more water on the rocks (another 1/4 cup), and continue baking the bread according to the recipe.
Tell us: What's your go-to method for creating a steamy oven? Would you give this method a try?