The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Ways to create steam?

butterflygrooves's picture

Ways to create steam?

I have a gas home oven and am wondering what the best way to create steam is. 

I have a small pan that sits on the oven floor that I dump boiling water into but I'm not sure it's doing the job well enough.  I have to have the oven door completely open to get the water into the pan and slide it back before closing the door.  I don't feel like enough steam isn't trapped inside when doing this.

I've heard of others on here using lava rocks or spraying the inside of the oven, or going so far as to MacGyver their home oven into a steam injection oven.

What is the best method for getting steam?  I just want a shiny, blistery crust every now and then...

Chuck's picture

The "best" way to make steam? Well I don't particularly relish becoming flame-bait, so...

My experience though is you'll find filling your pan with lava rocks works better than having the same pan completely open. With it completely open, there's too much surface area, and the evaporation surface is too closely linked to the rest of the water. The net result is so much evaporation of the whole reservoir of water that it cools down your oven significantly while not producing a whole lot of steam.

From what I can see, the lava rocks improve this two ways: First, by "covering" much of the surface they significantly reduce all the evaporation. Second, by "wicking" the water up into all the small channels in the foamy rock, it allows those bits of water to flash into steam without being tugged on by the whole reservoir of water below them.

Increasing the thermal mass of the pan may also be helpful. Common ways to do that are a) use a cast iron pan or b) add a whole bunch of old nuts and bolts or c) put a layer of new non-coated finishing nails in the bottom of the pan. (Old bricks that are still solid, wrapped tightly in many layers of aluminum foil, may also work. There's a significant danger of explosion though with miscellaneous rocks from outside, concrete blocks, crumbling and perhaps also new-style bricks, or direct contact with drips of water.)

As far as MacGyvering your oven, if you're seriously into DIY and such it may be appropriate for you. On the other hand if you have a dubious spouse or any second thoughts at all about a voided warranty or an oven that 's fairly new or an oven with electronic/digital temperature controls or aren't quite sure what to do first, my personal suggestion is "don't".

PeterS's picture

Water evaporates to form steam at 212F and atmospheric pressure at sea level and thereabouts. As you observe, water in a pan will absorb heat and evaporate to form steam in a 450F oven, cooling the oven in the process--which will then recover when the thermostat tells the burner to kick back on. 

We only see steam when water vapor is introduced at a point below the dew point, i.e. the atmosphere is saturated with water at that temperature and can't hold any more and it condenses out and we see it. 

To saturate an atmosphere inside our oven at 450F and see steam, we would have to be able to maintain a pressure of about 465psi--obviously that's not happening at home :)  We are never going to see steam in our home ovens until the inside temp gets down to 212 or lower, i.e. when we open the oven door.

It is more appropriate to talk about humidity: we want to add more water to the atmosphere in our oven increasing the humidity. Our dough goes in at room temp and is cool enough to condense some water vapor on its surface, that actuall heats the bread--but in turn, it evaporates again when the surface heats to 212F cooling the surface. Since the burner has kicked back on, eventually there is enough heat input to evaporate the surface moisture and start driving the temperature beyond 212F. If not, say we did not have a big enough element or burner, the bread would never bake or take forever to do so.

Adding nuts, bolt or lava rocks to a pan actually increase the heated surface area and will facilitate water evaporation (nucleation) driving up the humidity faster. A towel does the same thing to a point, but also may slow down the evaporation because it would inhibit somewhat the ability of the gas (water vapor) to escape the pan. Either of these methods should boost the humidity inside an oven faster than just a water filled pan. The process will be slowed if the nuts & bolts, lava rock or towel have to be heated up to 212F first.

For safety reasons, lava rocks and other high surface area objects  should never be added to water at or near its boiling point; they will induce immediate boiling and steam generation--often violently so creating a serious burn hazard.

flournwater's picture

I think Chuck provided a terrific essay on the subject.  You'll hear (read) all kinds of theories about ice cubes and other scientifically unsound ideas but it's all about getting water hot enough to evaporate and the mass of heated surface to heated water (not cold water) is the key to generating useful quantities (density) of steam.  I use a cast iron skillet, with an inch or so of boiling water at the outset, and add about half a cup of vigorously boiling water immediately upon loading the bread into the oven.  That's followed by a spritz or four of very fine water spray into the oven cavity about every fifteen seconds for the first minute of baking.  Because my bakes typically begin with 450 to 475 degree preheating the oven doesn't' have time to cool between loading/spritz cycles and the system works well.  My cast iron pan doesn't sit on the oven floor because it's actually cooler there than the first rack position so it's the first rack position that receives the pan of water and the oven center (or just above center) that receives the loaf.  My final oven temp. is adjusted after ten minutes of initial baking.

clazar123's picture

There is a post that talks about using an old wet dishtowel that is microwaved so it steams and then placed in the oven in a loafpan that has an inch of water in it. Place this in the preheated oven for a few minutes before loading the bread. I take it out when the crust is starting to brown and I want it to dry out. Works perfectly for me.

salma's picture

I have switched to SylviaH's towel method for sometime and I like the results. I have a dedicated square pan and a towel. I make the towel into a fan fold and lay in the pan, then I boil water and pour on till soaked and place in the oven as I am getting the bread ready to slide in over the stone. I place the pan on the shelf above. Good luck!

Shady Grove Baking's picture
Shady Grove Baking

Here is what I do...

I have a 9 inch round cake pan that I keep directly below my baking stone and I preheat the oven 50 F degrees above what the recipes calls for. The pan is in there while I preheat the oven.

Working quickly, I place my bread in and drop 5 to 8 ice cubes in the cake pan. The ice goes form solid to gas quicker (I think) than water does and does not affect the overall oven temperature as much as water would. After a few minutes I return the temperature to the specifed level.

With practice, I have this process down to five seconds or less. One of the major factors of heat loss is opening to oven door. Fifty degrees or more can be lost when the door opens.


Dragonbones's picture

I preheat the oven to its max temp (250C) for an hour with a rectangular cast-iron griddle on the floor which is large enough to fill most of the floor space. I open the oven with oven mitt covered hands to load a panned loaf (e.g. sandwich) onto a wire mesh rack an inch above the cast iron, or a bare loaf onto a tray or baking stone on that rack, but using a tray or stone smaller than the rack area so that I have room to dump water through the mesh onto the griddle. After loading the loaf I close the door, grab a measuring cup with 2/3 c boiling water, open the door, keeping my face as far back as possible, and toss the water quickly onto the griddle, closing the door quickly. This results in a massive amount of steam, and would risk steam burns if I weren't so careful with the oven mitts and my distance. It does help with oven rise as long as the dough is not overproofed. I then turn the temp down to the desired baking temp.

If you are baking a single boule, consider doing so under a cloche or in a dutch oven. As for blistery, I've read that you get that with loaves proofed overnight in the fridge but I don't have time to bake in the morning so I've not tried it.

The reason for the preheat to 250C rather than to the desired baking temp is that this helps offset the loss of heat when the door is opened for loading and steaming.

BeckyColeman's picture

Perhaps I did not pay enough attention during physics classes in school but I really cannot see how ice cubes can generate steam quick than boiling water.  My father always insisted that hot water froze quicker than cold water if put outside during icy weather but I was too lazy to try it.

Surely while the oven is heating up put a metal container in the bottom of the oven and then when putting the dough into the oven to bake pour some boiling water in too.  I think I will experiment myself but of course the steam or vapour or humidity may not be visible but the amount of water or ice cubes diminishing will be seen as I have a glass oven door.  As the oven is fairly new one can still see through it!

PeterS's picture

It takes more energy (about 15% more) for ice to go directly to water vapor (steam) than it does for water to evaporate. For equal weights of water and ice in an oven, the water will evaporate faster at any given temperature substantially above 212F.

The exception to this might be if the surface area of the ice is substantially greater than that of the water surface in the pan. It still takes the same amount of energy to convert the ice to vapor, but the increased surface area facilitates the energy transfer thereby speeding up the process.

Using ice cubes is a way to slow down the "steaming" process so that the humidity in the oven persists over a longer period of time.

Hot water freezing faster than cold water is an old wives tale. :)


Janetcook's picture

I tried numerous methods - spraying, ice, cast iron pan adding hot water, towels etc....and all produced variable results in my oven which is due to having a large baking stone on my bottom shelf.  It effectually blocks steam from rising and cools the stone above it - I even tried diverting the steam as shown on a thread by Debra Wink.....

I have finally settled on what works best for me in my situation - I now use dutch oven.  I either place the loaf down into it or on the lid - depending on the amount of support a dough needs while rising - slack doughs need more support than firm doughs.....

I initially began using a Lodge combo cooker that I got off of Amazon but have ended up using a smaller sized Le Creuset enamel coated DO simply because it is a whole lot lighter than the Lodge and my body was rebelling against hefting around that weight.....age has it's consequences :-)  The loaves I make are generally 500-600g total weight.

For a larger loaf a lid from a roasting pan works great.

Many options to choose from - you just have to settle on which one works best for you in your situation...

Good Luck!


wmtimm627's picture

Home baking is supposed to be enjoyable. I read so much about people agonizing over such petty things as oven spring and what a loaf looks like that makes something so enjoyable seem to be tedious. All these things like percentages make me feel like my idea of a fun thing has turned into a job that I wouldn't care to do as much. I use a large pizza pan in the bottom of my oven and throw a cup of hot water into it when I put the loaves in, reduce the oven temp and 2 minutes later add another cup of hot water. My baguettes turn out perfect every time.


Dragonbones's picture

Billybob, of course home baking should be enjoyable, and if worrying about oven spring, appearance and percentages puts you off, just have fun doing it your own way. But please understand that for many others, it IS enjoyable to aim for  good oven spring or a nice loaf appearance, or to get consistency of results or a greater understanding of what's going on through the use of percentages. I personally love to get a beautiful external appearance to a loaf, just as I like to make the food I cook look nice. The visual aesthetics are a basic part of the pleasure of good food (but taste is primary, of course). I disagree with your derision of this as 'agonizing' over something 'petty'. To each his own, I guess.

Wild-Yeast's picture

Replacing the oven window was a clue to the fact that liquid water and hot ovens are a tricky combination to navigate.  I've tried most of the methods over time - even "tenting"  a loaf inside an oven bag to prove that containment was sufficient to slow the evaporation rate of water from the crust - allowing it to remain elastic throughout the oven spring.  

Some Conclusions:

  • The oven door window should always be draped with a towel to avoid any water splash contact when open. 
  • Covering the dough with a containment chamber [cloche] - having adequate clearance for the oven spring with a flat rim for good seal when placed on the baking stone provides a "steam containment vessel".
  • Spraying the interior of the "cloche" with water before placing over the bread in the oven insures a high humidity environment.
  • 15-17 minutes at 500o F is adequate to realize maximum oven spring after which the cloche is removed to allow the crust to develop.
  • Be careful removing the cloche. The steam-air mixture can cause burns as it "spills up" into room temperature air. 
This method works extremely well for both gas and electric ovens and eliminates water from coming into contact with oven surfaces especially the door's glass window. Note that a cast iron dutch oven provides a similar containment structure...,
Chuck's picture

I don't want to drip on my oven window and crack it, but I don't want to fool with a towel either. So...

At my local hardware store I bought the biggest "sink tailpiece" I could find (it's a piece of very-thin-walled metal pipe, a foot long and 1-1/2 inches in diameter. I also bought the smallest size "pipe cap" (a rubber cup with a hose clamp around it). I put the pipe cap on the end of the tailpiece and tightened it (in my case it was a little too big, so I made a "spacer" out of some double-sided tape I found in my junk drawer). Voila. It easily holds a mug of water even when I tip it quite a bit, it's long enough to reach into the recesses of my oven, it doesn't drip, and the metal won't melt.

Before putting the bread in, I heat a mug of water in my microwave, set the pipe upright (the pipe cap is flat so the whole thing stands up by itself), and pour the hot water from the mug into the pipe. Then with the base of the pipe in one hand, it takes only a few seconds to open the oven with the other hand, pour the water where it needs to go (a pan with lava rocks in my case) with my hand safely outside the oven cavity the whole time, and shut the oven door again.

freerk's picture

That makes so much sense that I'm running to get my cloche today :-)!

BeckyColeman's picture

I have been making bread by the Jim Lahey method of using a Cast Iron Casserole as an inner oven.  In his book he says that the Knobs on Le Creuset Casseroles might melt.   After an article on his bread making methods appeared in the New York Times there was a spate of knob stealing from large stores!

I haven't got a Le Creuset Casserole as in England the size I would like is incredible expensive and they are almost as much on ebay.  However I do have a Cousances which I got from a Jumble Sale. (A jumble sale is a garage or yard sale in a rented hall usually for charity).  Even at 240 degrees centigrade the knob has not melted.

2foodwithlove's picture


i got a combination steam oven and have started to blog some recipes including a great focaccia dough that I made today ! 

I would love to swap / share recipes with all of you !

My blog is 

Let me know some of your favourite combination steam recipes :-)