Why Bread Bakers Care About Bottom Heat
Professional deck ovens produce excellent bread partly because their stone or steel decks inject direct heat into the bottom of the loaf the moment it is loaded. Home ovens, which rely on circulating hot air, cannot replicate this. A baking steel brings the physics of a deck oven into a standard kitchen — the dough hits a hot, energy-dense surface the moment it enters, and that immediate bottom heat drives oven spring before the crust sets.
Setup for Open-Bake Loaves
For open-bake loaves (no Dutch oven), place the baking steel on the second or third rack from the top. Preheat at 500°F for 45 to 60 minutes. If you have a second baking pan, place it on the rack below and use it for steam by pouring a cup of boiling water into it just after loading the bread. The steam prevents the crust from setting too early, allowing the loaf to expand fully before it firms up.
Using the Steel Alongside a Dutch Oven
Many sourdough bakers use a Dutch oven for the first half of the bake (covered, with steam) and then remove the lid to finish. Placing the Dutch oven directly on a preheated baking steel for the entire bake improves bottom crust development significantly. The Dutch oven's steel or cast-iron floor conducts heat from the baking steel upward into the loaf. The bottom crust comes out deeply caramelized rather than pale or soft.
What to Expect: Oven Spring
Oven spring is the rapid final rise a loaf experiences when it first enters the oven, before the crust sets. Good oven spring produces an open crumb structure and a loaf that looks like it belongs on a bakery shelf. The bottom-heat burst from a hot baking steel contributes to this by starting gelatinization at the base of the loaf immediately, which signals the crust to expand rather than firm. Most bakers notice a meaningful improvement in oven spring when they add a baking steel to their setup.
Bread Types That Benefit Most
- Sourdough boules and batards
- Baguettes and ficelles
- Ciabatta (particularly benefits from a very hot bottom)
- Focaccia baked directly on the steel
- Pita and flatbreads, which puff dramatically from direct contact heat
One Caution
For very high-hydration doughs baked directly on the steel without a pan, the dough can stick if the steel is not well-seasoned. Make sure your steel has a good seasoning layer and is fully preheated before loading. Semolina flour or a light dusting of cornmeal on the peel also helps with transfer.
