The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

How to get better steaming?

Mason's picture

How to get better steaming?

Hi everyone,

I regularly bake a whole grain sourdough (using cooked Kashi grains, cornmeal and 5-grain oatmeal), using Reinhart's WGB method (soak grains overnight along with prefermenting sourdough).  (It's basicaly his "transitional" whole grain loaf)

Today I baked four loaves, and was under some time constraints and my sourdough was not at its most vigorous, so I added yeast, too.  The flour is about 50/50 KA white whole wheat and KA white bread flour.  The loaves came up wonderfully!  But one much more so that the others (though they were treated identically up until they went into the oven).  Here's a side by side comparison:

As you can see, the one on the right opened much more, with a much better grigne.  I put the difference down to steam.  The explanation is the arrangement of my oven:

I have two large square pizza stones (From Bed Bath and Beyond--$16 each!) but I broke one in half to make a large baking surface on the top of the oven.  I use the other half for extra space next to the tray of lava stones I use for steaming.

When inserting loaves I put three loaves on the top and one next to the tray of lava stones.  That lower one obviously gets more steam; the more opened bread comes from there (moved to the top rack after 20 mins baking to crisp up the grigne).  It was very much softer on the top when I moved it.

There is a good 1 1/2 to 2 inch gap around the top stone on all sides, which should let enough steam up there.  (A gas will expand to fill the volume it's in.) My theory is that the oven vents the steam pretty well, so the steam doesn't stay around the loaves at the top of the oven.

My question is how to get more steam to the top loaves?

Blocking the steam vets is out of the question (I have seen reports here from folks who have fried their oven's electronics doing that).  

Would getting another oven tray for the top shelf of the oven and lining it with another stone better trap the steam in lower parts of the oven?  

Or perhaps I just need to pour on more water than the (guesstimate) 1 1/2 cups biking water I pour on the rocks.

Or perhaps move the whole arrangement closer to the top of the oven?

Any advice would be appreciated.  Thanks!  


flournwater's picture

IMO, the improved grigne in the loaf on the right may well have simply been a slight difference in the way you cut the slash.  It doesn't take much in depth/angle of the slash to dramatically affect the gringne.

If you can determine where your oven vents (it's usually to one side or one corner) and place the steam source on the opposite side of the oven it might help.  Steam permeates the environment in an enclosed space; it's simply water vapor.  So your stones may affect the flow of the steam, but shouldn't make a great deal of difference in the overall average humidity in the oven.

Mason's picture

Thanks for the response, flournwater.

The loaves were sliced very similarly (same angle nd depth, as far as I am able to control it).  All three of the loaves baked on the top seemed to set very quickly, while the bottom-baked one was very obviously softer o the top than the others at 20 minutes in, when I opened the door and moved and/or rotated loaves.

The location of the rock-tray on the same side of the oven as the steam vent is an important consideration, though.  I had not thought of hat.  I'l switch sides to the opposite of the steam vent hole.

pmccool's picture

makes me wonder if perhaps your oven is designed to use both the top and the bottom elements to maintain temperature.  If that is the case, the loaves on top are exposed to direct heat from the upper element at relatively close range.  That would lead to earlier drying and setting of the crust which, in turn, would limit the extent of the bloom.

It could also be that your oven is simply hotter at the top than it is at the lower levels.  The effect would be similar in either case.

One other factor to consider is that the steam pan, being adjacent to the lower loaf, may be cooling that small area of the oven enough to permit the lower loaf more opportunity to expand before the crust sets.

I'm not sure if any of these are going on in your oven.  You might have to use a couple of oven thermometers, one at each level, to know for sure what's happening.


Mason's picture

Thanks, Paul.  I'll check the oven manual (thoughI don't think it uses the top element to maintain heat).  

I'll check the temperature differential while steaming next time, too.  That'a a little hard to do, since the oven door's window is small and dark, and the oven light comes from the back of the oven.  So my thermometer is difficult to read through the window.


Mason's picture

Have any of you tried steaming by placing a steam pan at the top, rather than the bottom, of the oven?

It might be an interesting experiment to reverse the racks--steam pan on the upper shelf and most of the loaves on the bottom, to see how that affects things.  I'll try that too when I bake again next week.

mrfrost's picture

I believe somewhere in one of SylviaH's many blog posts, she effectively uses a steam tray on rack placed above the bread. This dual layer of stones may introduce a different dynamic, however(blocking some of the steam).

Besides, the steam issue, I wonder if the dual layer of stones, the thermal properties of the stones, preheating times, uneven heating, etc, is also causing the differences.

Specifically, it looks like the loaves on the upper stones are not getting the desired effects(good oven spring) produced by a well preheated stone. Are the bottoms of the loaves baked on top pale?

Similar to what you suggested your self, try reversing the set up. Single loaf, steam pan on top deck, dual loaves on stones below. If this theory is correct, the single loaf, even though steamed, should show less oven spring, while the loaves on the now well heated bottom stones, show better expansion.

I just think those dual layers of stones is causing the issues, somehow. I think Mark Sinclair(Back Home Bakery), may be able to shed light here. In one of his videos, he shows he gets beautiful baking on dual levels with his home oven,  but I don't think he used stones.

Also, do you notice a good cloud of steam in your oven, at least for the first minute or so?(oven window required).

Also, how are your results when just baking on a single level? What level position do you use when baking on a single level. This may be a check for Paul's theory if you still use what looks like the middle oven position of your pictued dual level set up.

Mason's picture

The loaves that baked the whole time on the top are a little paler than those that started or finished on the bottom, but not significantly so.  

The heating element on the bottom of the oven is closest to the bottom stone, so it heats more.  I have burned the bottoms of loaves there (that's why I move loaves from and to there after half the time).

I heated the oven to 490°F (by an oven thermometer on top of the upper stone) for somewhere between 40-50 minutes, so I think the upper stone should have been well preheated.

When baking on a single level I just use the top stones (I leave the bottom stone in there, but don't put anything on it).  Everything seems to bake well, but not as well steamed as I'd like.

There is definitely a good cloud of steam in the oven for the first while.  It pours out of the steam vent at the top of the stove for the first 15  minutes at least.

I think next time I'll move the rocks to the other side, put them on top and increase the amount of water I pour on.

I'll seek out the Mark Sinclair video too (but please send a link if you find it first).

Thanks again,


mrfrost's picture

Other Back Home tutorials/videos:

SylviaH steam from above.

Seems to me there may be others, but for now...

Again, being that you are doing 2 levels, with stones, there may be differences.

Mason's picture

I'll look around for SylviaH's post too.  Thanks.  (but links are appreciated if any of you know where to find it.)

Mason's picture

I see.  Here's Sylvia's method.  And a homage to it here by Wally. This definitely seems worth trying.