Covered Baking Revealed
I didn't want to hijack the other question where BROTKUNST suggested a turkey roaster cover so I thought I would start another thread.
I have been experimenting with various ways to cover the dough during baking for many Months. I have learned a lot about the effects of enclosing an area above the bread. The first thing that caught my attention was the clay cooker known as a Le Cloche. If you want a sure fire way to bake the NYT no knead recipe with out risking an expensive french pot then this is the answer. As often as not I just use the Bell top on top of the stone but it works without preheating a stone by simply placing the cloche bottom/top on the rack.
Next I tried the steam maker bread baker cover and steam generator. Yes it was expensive and yes it does work great. It is a little small and restricts the size to much for my style of baking but the addition of hot steam in an enclosed area was an eye opener. I can get beautiful baggett's just like I enjoyed in France and just as tasty. The flavor I later learned has little to do with the cover and everything to do with dough handling and fermenting. The special stainless cover has a hole in the cover where you blast steam into the interior and bake covered for 10-14 minutes depending on your desired crust. Again, the main thing to remember is that the stainless cover works. It's less important that the steam helps improve the crust. The dough creates some steam as it hits the hot stone or baking sheet as it warms up.
Then I met Susan of San Diego and her Magic Bowl. Susan bakes smallish Boules under a 4 liter clear glass bowl that are amazing! The interesting thing is that you can open the door briefly and check the progress of the oven spring and color of the dough. As she points out, the spring is still developing until the dough starts to get color or early browning. At that point she slides a spatula under the bowl and carefully removes the bowl to continue baking open. BROTKUNST at this point has demonstrated that a small object placed in the oven door will help release the steam and create a crispier crust. Even if you only try the bowl a few times, try it to get the feel for how your basic dough springs and how long it takes to get the skin set. Plus it's fun to see the dough spring as you peek.
Various other pots and pans you might have around the kitchen will work to cover the bread for the first 10-14 minutes. Measure your average free form loaf and make sure you use something that will allow for at least that much rise. I find that the cover helps improve the spring by about 20%. So a 5 inch rise uncovered might rise to 6 inches covered. The inexpensive Turkey roaster is a good thing to use because it has a handle built in the cover. You do need to ALWAYS use an oven mitt to protect your hand from the broiler coils. Some ovens use the upper heat elements during baking to provide a more even heat supply so this is worth understanding for safety. What ever you use I have found that the easier it is to place and remove the cover, the better I like it. All of my oven mitts have burn marks on the tops!
One other thing worth noting. I tried spraying water on the parchment paper around the dough before placing the dough on the baking sheet and the bowl on the dough. The additional water on the paper quickly turns to steam and I believe improves the crust somewhat. Be sure if you use a steel pan to bake on that it doesn't warp and "oil can" under heat. If it does warp out of flat, you won't get a good seal with any cover. I use a double layer "Insulated cookie sheet" that has a little raised fold up in the back that doesn't warp or a stone.
I hope this helps those looking for ideas and alternatives to creating a professional bakers steam oven. Using a cover will eliminate the need to toss water into the oven and usually produce better results if you are baking one loaf at a time.