Ever wonder how professional bakers get those beautifully domed loaves a bread with glossy brown crusts? The secret - at least one of them - is steam...
In the first few minutes of baking, loaves of bread will rise rapidly as the gases trapped inside expand and the yeast has a final burst of activity (this is called "ovenspring"). Steaming within this time helps keep the crust soft. This allows the bread to continue expanding freely.
The steam that has settled on the surface of the bread also dissolves sugars in the dough. As the bread stops expanding and the steam begins to evaporate, the sugars are left behind to caramelize (yum!) and create a glossy crust.
Steaming is really only useful during the first 5-10 minutes of baking while the yeast is still active and the internal structure hasn't set. After this time, the crust needs its own time to set and dry out.
There are several different methods for getting steam inside your oven and the trick is always doing it without losing too much heat. Personally, we prefer to set a metal pan on the oven floor and let it preheat along with the oven. When the time comes, we slide the loaves in and then we either quickly pour a cup of very hot tap water into the pan or toss in a handful of ice cubes.
Some bakers advocate using a spritzer bottle to spray a mist of water into the oven, but we feel that this lets out too much heat and doesn't really generate the same amount of steam as using a pan with water or ice cubes.
Also, you can add steam when baking any bread, whether it's a simple white sandwich bread or a hearty country round loaf.
Give it a try next time you bake!
Related: Working with Yeast: Be Not Afraid!
(Image: Flickr member RobAtSGH licensed under Creative Commons)
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Is there a reason for waiting to put the water into the hot pan? I usually just pour hot water in when I start the pre-heat, and by the time I put the bread into the oven, the water is boiling and there's a lot of steam in there.
My bread seems to be fine, but would it be better if I waited to put the water in?
It's worth noting that most ovens aren't designed for this, and some with electronic controls could potentially get damaged. It's also worth noting that some manufacturers will void your warranty if you do it...
Me, I have an old gas oven, so I don't worry. No problems as yet. What are the odds of problems with a modern oven? I have no idea.
Marisab - I think that if you have a lot of steam by the time you put the bread in, then your technique works just fine. Whether you put cold water in a pan to preheat your oven or hot water in the pan after it pre-heats, you still get steam, right?! That's an interesting approach, actually. I think I'll give it a try next time!
Evan - You make a good point, though I've been doing this for years in a new-ish gas oven and haven't encountered any problems (that I know of!).
why is it that hot tap water and ice cubes are the two things that work? why wouldn't cold tap water work, if ice cubes also work? could someone explain the science behind that?
Do NOT pour water or throw ice cubes on the bottom of your oven. It can short out your oven or cause all other kinds of problems. Bad, bad idea. Please don't spread that misinformation.
You want a blast of steam at the beginning, so pour boiling water into a preheated pan in the oven. Another option is to bake the bread in a container like a pre-heated dutch oven (ala Mark Bittman's no knead bread recipe that was so famous), or a ceramic baking dish with a lid designed for this purpose. The Baker's Catalogue sells those. That's how you get a crackling, crisp crust.
There is another way to get that same effect without having to add steam to your oven. It just requires covering the loaf with a simple disposable lasagna pan or metal bowl for the first 10 minutes of baking. It traps the steam from the moisture of the bread, much like a fancy cloche or dutch oven. Simple and cheap!
I just did a post about this method if you want to see it in action! http://www.artisanbreadinfive.com/?p=510
Happy baking, Zoë (co-author artisan bread in five minutes a day)