Professional bakers use steam ovens to keep baking bread from losing too much moisture during the initial several minutes of baking. You can get a similar effect at home with a sheet pan and a spray bottle.
Picture: Rebecca Siegel/Flickr
I can't seem to let a guest stint on Lifehacker go without at least one baking tip. When you ferment and proof your bread before baking, that's when the yeast and bacteria in your dough draw out flavours from the wheat and build structure in your dough. When you put your loaves in the oven, the heat gives the yeast a chance for a final push in the first few minutes. The loaf will rise even more, which we call oven proofing or ovenspring.
Steam helps keep the crust soft during the first 10 minutes so the loaf can get that final expansion. It also helps dissolve sugars on the surface of the dough that caramelise during baking and give you a glossy, crisp crust. You can get pretty close to the effect of a steam oven at home.
When you preheat your oven, heat it about 25 degrees hotter than your recipe calls for and put a sheet pan on the bottom rack to get nice and hot. When you put your bread in, pour about a half cup of water onto the sheet pan. You have to do this without pulling the rack out because you want the steam to stay in the oven, so be careful. Using a spray bottle, spritz the sides of your oven with water a few times and close the door. Wait about 30 seconds and spritz the sides again. Wait another 30 seconds and do it one final time, then turn the oven down to the suggested temperature and bake as you normally would.