Steam in bread baking: how steam can transform your bread from dull to dazzling

Have you ever loaded your perfectly risen artisan bread into the oven, only to discover a dull, constricted loaf at the end of the bake? How do artisan bakeries achieve that lovely golden, crisp, shiny crust? Steam in bread baking is the key!

Steam in bread baking-17

Adding steam during baking doesn’t just enable a great rise in the oven, and help develop a beautiful, crackly crust.

Steam in bread baking promotes an open crumb structure, as well as rich flavor and color. Click To Tweet

But how can we get results like this at home?

Today we’re going to test different home methods of adding steam in bread baking. Our test bread is the Pain Au Levain recipe used in our Baking School. This lovely sourdough bread has a mild flavor and a wonderfully open crumb.

Pain Au Levain is the perfect guinea pig for our steam tests. We can first admire the loaves baked in class, utilizing a professional steam injection oven. Next, we’ll use the same recipe at home to test various baking and steaming methods. Which home steaming method will bring us closest to professional oven results?

Steam in bread baking via @kingarthurflourThat’s the Baking School’s steam injection oven on the left, and closeups of the Pain Au Levain loaves baking on the right. Steam in bread baking via @kingarthurflourAnd here’s a beautiful loaf straight from the oven. See what we’re aiming for here?

If you want to follow along with our tests and bake the Pain Au Levain bread, you can find the recipe and directions here. If not, these steaming methods will work with any artisan bread recipe.

Time to bake

We’ll bake this bread at 450°F for 35 to 40 minutes. If you plan to use a stone and a cast iron frying pan (for steam), preheat both of these for 60 minutes before baking.

A brief note about scoring (a.k.a. “slashing”)

Before we get too steamy, let’s take a moment to consider the importance of scoring your bread before baking. Those cuts in your bread aren’t just decorative! Scoring the loaf provides a strategic vent to release fermentation gases during baking. Good scoring, along with proper steaming, allows your loaf to open up fully. Without scoring your loaf is likely to burst open at weak spots and end up oddly shaped and constricted.

Steam in bread baking via @kingarthurflourThe Pain Au Levain bread requires one long “ear” or “lip” cut down the center of the loaf. Notice how the blade is angled, and only one corner of the blade touches the loaf.

For more tips on scoring, check out this blog post and helpful video.

Ways to add steam in bread baking

Before we get started, please remember to suit yourself up with good oven mitts whenever you’re working with steam!

Steam in bread baking via @kingarthurflour

Steam in bread baking: Method #1

The simplest method of adding steam to your oven is to spray the loaf with warm water prior to putting it into the oven. Spray the oven once the bread is loaded, and then again about 5 minutes into the bake.

Unfortunately, this method doesn’t offer much moisture, and the effects on the bread are minimal.

Steam in bread baking via @kingarthurflour

Steam in bread baking: Method #2

In class our instructor illustrated method #2. She loaded the loaf onto the preheated stone and then poured about 1 cup boiling water into a preheated cast iron frying pan on the shelf below. This method works quite well, as you can see from the resulting loaf on the right.

Steam in bread baking via @kingarthurflourI tried the same method at home with the addition of preheated lava rocks in the frying pan. My loaf looked great, too.

Steam in bread baking via @kingarthurflour

Steam in bread baking: Method #3

If you want to enhance the effect of method #2, a large metal bowl can be placed over the loaf to trap the steam and keep it close to the surface of the bread during the oven-spring period.

This is part of the reason steam injection ovens get such great results; the individual “decks” of the oven aren’t very high, keeping the steam where it’s needed—on the surface of the loaf.

Load your loaf onto the preheated stone and then place the bowl over the loaf, with the front of the bowl overhanging the stone and leaving a gap that lines up with the preheated cast iron frying pan below.

Pour about 1/2 cup bowling water into the frying pan and shut the door. Remove the bowl 15 minutes later and allow the bread to finish baking in a dry oven. A butter knife comes in handy to lift the hot bowl, which will be hard to grab with oven mitts.

If steam is so great, why finish in a dry oven?

Steam is vital during the oven-spring period so that the surface of the loaf remains moist and expands easily. However, once the yeast has died and the loaf is set, moisture is no longer a friend to your bread. Too much moisture throughout the bake can lead to a thick, rubbery crust.

Steam in bread baking via @kingarthurflour

Steam in bread baking: Method #4

A Dutch oven or cloche also works to keep the moisture given off by the bread during baking close to the surface of the loaf, allowing for the same kind of expansion and shiny, golden crust.

Although we don’t generally recommend preheating empty any of the baking pots we sell (a method popularized by Jim Lahey and Mark Bittman about a decade ago), Emile Henry’s 4.2-quart Dutch oven can be preheated empty, as can their new potato and bread pot. These pots heat up more quickly than cast iron, so 30 minutes preheating should be sufficient. Remove the lid after 20 minutes of baking.

Never fear, though, if you don’t have a pot suitable for preheating empty (or don’t like messing with a very hot pot), you can still get great results baking in your Dutch oven. In the photos above, I put the Staub Dutch oven with its cargo of risen bread into a preheated oven; but if you prefer a cold start, that works great too. Again, it’s important to remove the lid and allow the bread to continue baking in a dry oven after the loaf is set (remove the lid after 25 minutes in a preheated oven, after 30 minutes when baking from a cold start). Overall baking time will be a little longer when baking from a cold start.

Steam in bread baking via @kingarthurflour

Let’s compare our results

The loaf on the left was steamed with method #1. This loaf failed to open properly where I scored it, and the crust is dull in color. Notice how the crumb structure is relatively dense, in comparison with the other loaves? It will still be a delicious loaf of bread, but more steam would have made it even better.

The loaf in the center was steamed with method #2. It opened up beautifully and has a lovely brown crust, although not quite as shiny as loaf #3.

The last loaf was baked with method #3. See how shiny and blistery the crust is, and how open the crumb?

Both this loaf and the loaf baked in the Dutch oven were refrigerated overnight in their shaped form before being baked the next day. This added step contributes to a more blistery crust, as well as more sour flavor.

Overnight refrigeration is particularly useful when you know your schedule will interfere with baking bread on its own schedule — when it’s perfectly proofed and ready to go into the oven.

What happens when you over-proof your bread?

Have you ever wondered what effect allowing your dough to rise too long in the shaped form has on the final outcome of your bread?

Steam in bread baking via @kingarthurflour
Notice there are lots of large gas bubbles right under the surface of the loaf above. This is a sign that the loaf has been allowed to rise too long before going into the oven. I deliberately over-proofed this loaf as an added experiment, and baked it using the bowl method of steaming (#3).

Steam in bread baking via @kingarthurflourThe loaf on the right is my over-proofed loaf, and the loaf on the left is loaf #3. While my over-proofed loaf didn’t open up quite as much as loaf #3 and has a slightly denser crumb structure, it still rose well and colored up nicely.

Steam in bread baking via @kingarthurflour

Steam saves the day!

If we compare the crumb of my over-proofed loaf (right) to the relatively closed crumb of loaf #1 (left), we can see how even an over-proofed loaf will fare better with steam than a loaf that doesn’t get enough steam.

Keep in mind that not all breads will endure as well as this one did when allowed to rise too long. Have you ever scored your loaf, only to see it deflate like a poked balloon? Or has your lofty loaf collapsed in the oven? These are sure signs that you’ve let your bread rise too much before baking.

I hope you’ll give our Pain Au Levain recipe a try and test out some of these steaming methods as well. Steam really does make the difference!

You can view the Pain Au Levain recipe here, along with the printable version.

Steam in bread baking via @kingarthurflourBig thanks go out to Lee Clarke for taking these beautiful photos during class, so I could get down and dirty with the dough!

And if you ever get a chance to take a class at one of our baking schools, I guarantee you’ll have a great time, and go home with a wealth of baking knowledge and techniques.

Barbara Alpern
About

Long time professional artisan bread baker, caramel maker and member of our Baker Specialist team, Barb grew up in Ann Arbor, Michigan and has four grown sons. She has baked in Michigan, Maine, Vermont, and Texas (if you count baking cookies for her son's wedding!).

comments

  1. Dana Johnson

    While the results are clear, I do wonder about the purported cause being keeping the outer crust soft during the initial oven rise phase. At least for home ovens at 450-500 F. Steam is not what we usually see it as a cloudy vapor. It is invisible and contains a huge amount of energy which it releases when condensing on anything. That is why steam burns are so instantaneous and severe. I do wonder if the action of steam (water vapor) isn’t to quickly impart a large amount of heat to the loaf exterior much more rapidly than either the 500 degree air or radiant heat of the oven can do alone. Convection ovens try to do this by keeping fresh hot air against the food, but while one gram of air can exchange one calorie of heat per degree, steam can exchange 540 calories / gram plus one more for the steam temperature. That steam does this without drying out the surface, it certainly will cook it fast. Remember steam radiators? They were a very efficient way to move a lot of heat around a house. It is one of the best heat transfer methods in existence.

    Reply
    1. Qq

      If your idea of the mechanism were correct, I would expect spraying the loaf to ruin the effect, since it very clearly slows down the process of surface hearing of the loaf (all that extra energy to input just to get the water warm).
      Additionally, while steam is great for heat transfer, once condensed on a surface is water, and it requires just as much energy to heat up that water as originally conferred to the surface through condensation. In other words you actually do not get an overall faster heat-up process for the loaf or the oven as a whole.

  2. Dave

    my bread baked in a covered baking dish has a very tough crust, it is even hard to cut until it has been in a plastic bag for a few days. how can I prevent this?

    Reply
    1. Barbara Alpern, post author

      Hi Dave, are you removing the lid part way through the bake? It’s important to trap the steam during the initial part of the bake, but to finish baking in a dry oven. Be sure to remove the lid after 20-30 minutes of baking, depending on which Dutch oven method you choose. If you’re baking at a temperature over 450 degrees, it may also be helpful to lower the baking temperature a bit.
      Barb

  3. Tamara

    How long can you reuse the lava rocks before they need to be replaced? What is the proper care for the lava rocks? BTW- I’m a beginner baker and I truly appreciate this blog! The articles are so helpful! Thank you!

    Reply
    1. Barbara Alpern, post author

      Hi Tamara, I first learned about using lava rocks from Maurizio Leo’s blog about adding steam to your home oven, and he figures his bag of lava rocks will last him for life, so I really don’t think you need to worry about them deteriorating very quickly. I just store mine in the cast iron pan I use for steaming, and, like Maurizio, I’m still on my first hand full of lava rocks after at least a year of use.
      Barb

  4. Brenda

    I used method two in my oven for the last 10 years when baking bread, using a baking stone, and lava rock in an 8 inch aluminum pan on the floor of the electric convection oven. Now I have to replace the oven because the inside RusTED. How can I avoid ruining my new oven and still create steam for the breads?

    Reply
    1. Barbara Alpern, post author

      Hi Brenda, you might want to consider using the Dutch oven baking method, which I find to be the easiest and most effective. It doesn’t require adding moisture to your oven, and yields the closest results I’ve seen to the breads I used to bake in professional steam injected ovens.
      Barb

  5. Lukasz skurzok

    Hi i love making bread and my question is
    If im using convection oven at work can i use steam on 230 celcius degrees for first 15 min and then change for baking for another 10-15 min?

    Reply
    1. Barbara Alpern, post author

      Hi Lukasz, professional convection ovens vary considerably as far as recommended steaming and vent times. I would recommend consulting the oven manual and doing a little experimentation to discover what works best for the breads you’re baking.
      Barb

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