Do We Really Need Steam?
I was exploring English Muffin bread, and there seem to be mostly just two recipes "out there." One is the King Arthur version, the other uses an egg. Neither one tastes anything at all like an English Muffin. So I went looking.
I found a recipe for classic English Muffins, which also used (what they called) a biga. To me, it's actually a poolish, but hey...who am I to argue? I made that recipe, and just dumped it into a loaf pan instead of frying them in a pan. (I did a couple of rises to double, but no real shaping -- it wouldn't hold a shape.)
This recipe was so wet, it was extremely hard to work with. It's supposed to be fried, like crumpets, so it's more like a heavy batter. Learning how to work with high-hydration dough, I was able to manipulate the dough. To me, it seemed a lot like ciabatta. But Holy Smokes, did this dough rise!
Long story short, when I finally reworked the recipe, I ended up with a fantastic Italian Sandwich Bread! Seriously good stuff! I suspect the Italians had their bread, and the British came along and fried it.
For about 15 years I've been attempting to replicate a particular type of sub roll. My examples are from Turano or Gonella in the Chicago area. Another example is Amarosa out of Philadelphia. And there's a place in New Orleans that sounds similar. It's been impossible. There's a recipe here on Fresh Loaf I was about to try, when this astonishing miracle of serendipity happened.
I'm now making the 8" rolls, and will also add in whey. With just plain water the bread was superb (I'll do a recipe later), but the rolls have slightly too much crust. Obviously: Steam!
Have you ever put a pan of water in the oven and watched it boil? Like when you're braising a casserole or meat/poultry? The water's happily boiling, but...there's no steam! Why not?
Check this out from a thread on the physics and thermodynamics of steam and vapor:
Steam in general refers to the gas phase of water. Steam can be the same as water vapour in some contexts. In more casual usage, steam can refer to the mixture of vapour and aerosol liquid water droplets suspended in the vapour. The "steam" you see rising off boiling water for example, is the second type. What you see is actually condensed liquid water; as water vapour itself is not visible to the naked eye.
I tried several mechanisms to get steam, and came to understand why surface area matters. However, I got curious and put a plain pan of water in the oven at 350F. No steam. Then I put a Pyrex pie plate in the same oven and before I even could set down the pan on the rack, it clouded up with "fog." That's the same as steam, I believe.
Why do we want steam at all? Most here know it's because it retards the formation of the outer crust, keeping it soft so the inside of the bread can continue to expand. We want the "skin" of the loaf to stay somewhat cool until the loaf has risen all the way. Then, remove the steam and allow the final browning.
Hmm. So what's actually cooling that "skin?" Isn't it the water, at just over 212F, being cooler than the surrounding hot air (at 350F)? In fact, isn't the reason I got instant fog on my glass plate is because I was putting a room-temperature surface into a super hot atmosphere filled with.....water! As vapor!
The loaf going into the oven is, what...around 80F or thereabouts? Somewhere around room temperature. Ordinarily, the humidity in the preheated oven is extremely low. "Ovens are designed to remove humidity to promote even baking. A 350-degree oven has a relative humidity approaching zero." - AI
The small amount of water in the outer skin will boil off quickly in the hot oven, leaving the flour (and possible fat) to start burning: the browning. Adding continual water will prevent the flour from drying out and burning. Ergo, steam provides a source of water. The steam doesn't matter. We perspire when we're hot because the heated "water" of the perspiration evaporates. The exchange of energy removed heat from the body. But the surface of a loaf of dough has no way to "perspire" or sweat. :-) Gotta spray it with water, like keeping a cat cool.
If I put a wide pan with some boiling water into the oven, it can sit while I'm preheating or for some time. It will continue to emit water vapor, since a) it was 212F when I put it in, and b) the oven is well above 212F. Ergo, there is constant water vapor in the oven "air."
When I then put in an 80-F piece of dough, it will immediately develop condensation on the surface -- the "skin." Right? The exchange of energy between that condensation, its evaporation, and the gradual increase in temperature of the dough "should" produce the same effect as steam. Right?
I shouldn't need to actually see billowing clouds of white steam. Those clouds are really only the water vapor condensing rapidly in the hot air. It may deposit on the dough, or maybe all over the oven, but it's no different than actual fog or morning mist over a river.
Seems like it, anyway. So I'm going to try for my thin crust with just a 10x13" roasting pan and about 1-2 inches of boiling water....just sitting there. It's a lot easier (and safer) than throwing water into a pan that's already hot. And less cumbersome, and I don't need lava rocks, towels, or anything else. Just boiling water. :-) We'll see.
Side note: I tried the steaming cotton towels rolled and put in the preheated oven. It sort of works, but the bottom of the towels remained wet, while the upper parts dried out fairly soon. Surface area exposed to hot air. The towels may have a lot of water, but it doesn't "wick" to the upper surface quickly enough to compensate for evaporation.
I suspect you are right, Asburger. Huge vapor clouds -- and the accompanying sizzle from throwing ice cubes into a super-heated cast iron pan -- are for show. To tell our disbelieving brains: look! steam!
Rob
A very long time ago when I worked in a Physics lab, we had to take a large piece of stainless steel, with a complex shape, to be vapor degreased. Back then it was common to use trichloroethylene for this purpose. It's a clear, but volatile liquid at room temperature and turns into a heavier-than-air gas at moderate temperatures, about 190 deg F. At the cleaning facility there was an enormous tub without a cover. There was hot vapor in the tub - you could make out a slight foglike effect but it was clear above.
Our part was lowered slowly into the tub by a hoist above it. When the piece sank below the top of the tub, clear liquid suddenly appeared like magic and flowed all over our part. That was the condensed trich doing its cleaning job. It was a very dramatic sight that I remember these more than 50 years later. After some minutes, our part heated up to the vaporization temperature and liquid stopped condensing on it. The job was done.
This is beyond doubt what happens with a loaf of bread-to-be as well. What AsburgerCook has written is no doubt correct. There are a few other points to think about, though. One is that water condensing on the surface of the bread releases much of its heat of vaporization to the surface of the bread, and that's a lot of heat. So the surface of the bread can heat up quickly somewhere between the dough temperature and the boiling point of water. It can produce a gell-like effect, and that gell-like skin will stay moist for some time. This is the origin of the sheen that I get on many of my loaves. This effect reduces the drying and burning effect of the hot oven air for some time, and also should help the loaf to expand.
During this time, a baking steel or stone if used keeps pumping a lot of heat into the bottom of the loaf, promoting good rising.
Another thing to consider is that ovens, whether by design or accidents of construction, don't hold water vapor in very well, and many ovens can be damaged by too much water vapor - mostly the newer electronic controls, I think. Of course they have to be able to withstand some moisture because many foods will give off a lot. If you start off with a lot of water, even during preheat, the moisture will be in the oven that much longer than if you throw in the water later when you put the loaves in. I don't know how to balance this out, but it must be a factor in play.
Another difference between putting water in during preheat and throwing it in later (and producing clouds of steam) is that throwing it in later will drastically lower the oven temperature for quite some time. The details will depend in the oven design, the location of the steam generating apparatus, the size and location of the baking steel, and so on. I routinely see the temperature above the steam pan go down below 300 deg F and stay down for a long time. The air above the bread stays cool for a long time, too.
Because of this, the effective temperature that bakes the loaf during the first part of the bake cycle is much lower than the oven temperature setting and much lower than you think. Our home ovens take a long time to recover their temperature. I have proved this by turning by oven setting down to 300 deg F or even 250 right after throwing in the water to make steam. The bread baked the same way as if the temperature setting and been kept high the whole time. Now I routinely turn it down to 300 or 350 deg for 12 or even 20 minutes before returning the setting to 415 of 425 deg F. The bread may even bake more quickly (hard to be sure), than with the setting kept high, and it's certainly baked at least as well and, it seems to me, more consistently and with less tendency to burn the crust.
You want to find a balance between creating high humidity during the first part of the bake, and allowing the bread to dry out better during the latter part. If you start heating the oven with some amount of water, it may or may not still be there generating its water vapor by bake's end. I know that when I throw in my 12 oz of tap water into the steam pan with its rocks, the pan will be dry before the end of the bake. BTW, I used to boil the water before throwing it in, but when I tried not pre-heating the water it didn't change how the bread baked. So now I don't preheat the water. I also tried adding more water to the steam pan after say 5 minutes. That didn't generate another visible cloud of steam/water vapor, it left some unevaporated water in the pan, and didn't change the baked results so far as I could see.
I should probably try preheating the oven with water in the steam pan. I've toyed with the thought but haven't actually done it. One thing I'm sure about is that I will not be removing the steam apparatus in the middle of the bake as some people do. That's just asking for serious burns and scalds if something goes wrong.
TomP
Dayum, there's a lot of good stuff here! I was just thinking about having the effect of steam without freaking out about the billowing clouds. I hadn't really contemplated that people are already doing this! LOL! It reminds me of that Helen Rennie who has a brainstorm, figuring it's new, then goes out and looks around. Only to find that no, it's not all that new. :-)
Okay: My understanding of the baguette thin crust is that there's about 15 minutes of steam at the start of the bake. Then the water/steam is removed for the remaining (whatever...20mins or something) time. You sound as though you're specifying steam for the entire bake time?
I've used a foil tent over damp dough in a hot oven, then removed the foil after 10+ minutes, which I now know is using internal moisture from the bread and capturing the vapor. I've got a couple of King Arthur recipes that also start with a tent, then remove it. I think I'm now understanding the "why" of that.
So I believe?...that this "gel" you're referring to is what I want, right? It's starches? Is that gel the basis for what eventually becomes the crust? What makes the gel thick, for the artisan crust, versus very thin and shattering? Is it the time involved with the water moisture?
I have a basic home electric oven (GE), with nothing fancy other than self-cleaning. I hadn't even thought about the reduction in temperature from the water, and that totally makes sense. It's why I figured I'd have the boiling water go in during the preheat.
The water -- maybe 1-2 inches in a 10x13" steel roasting pan -- would be at 212 minus temperature loss when I pour it in from the kettle. That goes into a pre-heating oven, and I'm "assuming" that the oven thermostat will simply read the air temperature.
Therefore; the combined effect of the heating element and the added water and steel pan will make a cumulative average. So when the oven Pre-Heat beep goes off, that means the air temp in the oven has reached my baking temp. Let's say 350F. As such, the water will have reached 212 and the oven air is 350. (Interesting to put a heat proof hydrometer in there! Probably melt at >300 though.)
I've done a lot of braising in this oven, so I'm not worried about moisture escaping to possibly impact the controls. There's a single vent under a back burner, but overall the oven holds a good temperature. I should likely use an oven thermometer for a better reading. I hadn't even thought about the drop of 50-degrees, which then stays there regardless of what the oven has to say about it.
I think -- not sure yet -- that these Italian rolls are going to work at 350 rather than a more typical 450. This is a big experiment based on a completely accidental result from changing the English Muffin recipe. I know what I want, but have spent probably 20 years trying to replicate it. Haven't until now, so there's time for experiments.
The oven will have to keep the water at boiling temp. I foresee perhaps about 10-15 minutes of vapor, so I'm guessing I'll have about 260 cubic inches of water available. I doubt all that water will vaporize in the 15 minutes, wouldn't you agree?
Interestingly; when I used the rolled cotton towels, the bottom was wet and the tops were completely dry -- that wick effect I mentioned. With just plain water sloshing around (who knows, could have an earthquake), as the upper layer vaporizes, the lower layers should.... climb and encounter the hot air? Like turnover in a lake?
Therefore, it sounds like my main variable is going to be an accurate 350 degrees. And even there, I'm fascinated that you didn't experience a difference baking between the 300 and 350 or whatever your start point was. I've "kind of" noticed that, but figured it was more about a) how quickly will the bread finish baking, and b) how dark will the crust eventually become.
I'm making a faux croissant with egg wash, and when I baked at 350, I got a light golden crust in 11 minutes. Raising to 375, got a better crust color. Then I saw a hack to start at 400 for 10 minutes, then drop to 350 for around 10 minutes, and that was excellent. So it seemed like the temperature was affecting only the Maillard reaction AFTER the flour had dried out.
I also know that it takes a long time for a pie to brown because as the crust and filling are climbing up to 212, it all plateaus when the water is in the process of vaporizing. Then, like a rice cooker, after the water is "gone" for the most part, the crust browns.
Ergo, the bread crust should be similar, right? Totally cool description of what you've already found -- I think this is going to work! If so, I'll write out the recipe. :-)
Added note: Removing the water part way through the process won't be a problem. I move pans in and out of the oven all the time, with various amounts of liquid sloshing around. This is a turkey-roasting pan, after all, and kind of designed to be handled in such a way. Plus, I see no reason why I can't put the water on the same oven rack as the bread. A second, lower rack could actually increase the possibility of an accident.
It's not as simple as that. The air in the oven will not be at the same temperature all over. The air near the water source will be cool and there will be temperature gradients all over the oven. The longer the oven gets preheated, the more heat will get stored in the oven structural material and the more constant it will manage to hold its temperature.
On top of that, the oven thinks that its "temperature" is whatever the oven's temperature sensor sees at its location. It won't necessarily even be an average of the temperature throughout the oven. Also the temperature gradients will change when the heating element comes on. The idea that a home oven has "a" temperature everywhere during baking a loaf of bread can be far from the truth. It's too complicated to sort through with any accuracy, so in the end - as always - you have to proceed empirically, guided by the generalities.
As to a thin crust, I don't know for sure but I think the a high temperature at the crust must play a big role. Think about what happens at the loaf's surface. Heat transfers from the oven air but slowly. Steam in the oven will transfer heat much faster since the water will condense and hive up its heat of vaporization. The surface will absorb water and start to gell, but the interior will be slower to heat up.
The surface has to dry out before its temperature can rise high enough to dry out brown and brown. If this happens slowly there will be a thicker region near the outside that can dry out and cook this way. If the temperature gradient through the surface is high, that's when a thin layer of the crust can dry out and brown before the rest of the loaf gets cooked. To get a high temperature gradient you need need a very hot oven.
It's not as simple as that. The air in the oven will not be at the same temperature all over. The air near the water source will be cool and there will be temperature gradients all over the oven. The longer the oven gets preheated, the more heat will get stored in the oven structural material and the more constant it will manage to hold its temperature.
On top of that, the oven thinks that its "temperature" is whatever the oven's temperature sensor sees at its location. It won't necessarily even be an average of the temperature throughout the oven. Also the temperature gradients will change when the heating element comes on. The idea that a home oven has "a" temperature everywhere during baking a loaf of bread can be far from the truth. It's too complicated to sort through with any accuracy, so in the end - as always - you have to proceed empirically, guided by the generalities.
As to a thin crust, I don't know for sure but I think the a high temperature at the crust must play a big role. Think about what happens at the loaf's surface. Heat transfers from the oven air but slowly. Steam in the oven will transfer heat much faster since the water will condense and hive up its heat of vaporization. The surface will absorb water and start to gell, but the interior will be slower to heat up.
The surface has to dry out before its temperature can rise high enough to dry out brown and brown. If this happens slowly there will be a thicker region near the outside that can dry out and cook this way. If the temperature gradient through the surface is high, that's when a thin layer of the crust can dry out and brown before the rest of the loaf gets cooked. To get a high temperature gradient you need need a very hot oven.
TomP & Asb -- I wonder if my experience baking with an Anova oven might add something to this steamy tale.
The Anova has a steam function you can set. When it is steaming, it releases a trickle of white vapor at the bottom of the box outside the oven -- seemingly where the element that heats the water is -- but inside the box the air never visibly changes. Also, it has a super-responsive digital temperature read-out and the oven temp doesn't seem to waver due to the steam injection -- though it falls dramatically (perhaps 50 C or more, in my memory) when you open the door and load the bread and takes close to a minute to bottom out and another 2 or 3 minutes to rise back to the temperature you had set.
What's more, since the Anova has a giant window and good quality interior light, you can watch the bread rise. That's how I discovered that, contrary to my expectation (and contrary to my later experience with a dutch oven), the rise does not cease when the steam ends and the crust supposedly hardens. Rather, it keeps going all through the bake. For many of my breads, the final, Eiger-like peak (sorry, I was using the oven at my brother-in-law's apartment in Switzerland) didn't pop into place until about a minute before the bread was done.
Rob
That's very interesting. Thanks, Rob. I keep toying with the idea of getting an Anova but not so far.
In my oven, most of the rising occurs in the first five or so minutes. I don't see much after that. The door is too hazy to be able to really see through so I am going by quick peeks. I'm sure that's why I don't often get really open crumb. Well, it can be very open, just not with large, irregular holes. I've gotten some great, thin, shattering crusts, though.
No. Enjoy!
Interesting discussion. I have a new oblong Dutch oven, that is bigger but also slightly lighter than my previous round one and seals more hermetically than the old one. I'm still figuring out how to bake with it because, even with my most consistent loaves, the bread is not coming out like with the previous one. Too much oven spring twice, darker crust twice, and too thick crust once after reducing oven temp by about 10C.
Made me realise how even tiny changes to the baking environment can have significant impact on the final result. More than maybe we realise.
This past thread might help shed some light on this discussion.
Thanks. ReneR, Doc's post was really interesting. It aligns very well with my thinking except I never worked through the numbers. One difference is that I have always assumed that radiant energy from the oven walls played a small part at our temperatures. If Doc got the numbers right, that's only partly the case.
BTW, the reason the term (T1^4 - T2^4) is not the 4th power of the temperature difference, i.e., (T1 - T2)^4, is that T1^4 is the radiant power emitted by the the oven structure and T2^4 is the radiant power emitted by the loaf. The net power input is the difference of the two.
Doc wrote a cogent saying in a related thread:
"reject" might be a little strong, but "be very skeptical about" fits the bill for sure.
I'm all for empiricism, but we still have to make bread where there are a lot of things we cannot measure (see LAB vs yeast debates, for another example). So we are constrained to wander into the realm of what I have heard being referred to as 'qualculation' and trial and error, which are acceptable heuristics I think for what we do (and maybe add to the fun of it?!).
Having said that, I always thought that radiant energy might have more of a role than assumed in the case of ovens, as trapping radiant energy is an important part of what ovens are supposed to do.
Where did that come from? I've never seen it suggested. An oven needs to be well insulated for both safety and efficiency, and unless its walls are somewhat transparent in the infrared range an oven isn't going to leak much radiant energy whether that was intended or not.
If radiant energy played a large role in normal cooking (except for a broiler element), then a convection fan would have much less effect (since it would increase. a smaller fraction of the cooking ability). DocDough estimated 20%. If so, that's not large but not negligible either.
Seeing the bricks on the floor of a wood-fired oven turn white around the focal point of the dome of the oven with a relatively small amount of burning wood, I would say it is an important part of what ovens do.
I seem to also remember my A-Level physics textbook with a diagram of an oven and the rays bouncing around the walls inside. But yes, for a home oven it is not going to be as important.
Fascinating, Rene. I have a giant oblong dutch oven that is heavier than my round one and has a more secure seal. Bread in it has also been variable: sometime I get a fantastic, super-high rise, sometimes more compression, sometimes a perfect crispy crust, sometimes tough & heavy.
Rob
It was really funny with this DO. I went off to a catering trade shop and treated myself to a new batard banneton and the new oblong DO in which to bake the batards.
Got home all excited about all the new possibilities my new kit would provide and confident about the outcomes, now that I have been achieving consistently good bread with my old setup. How different could the shape of the banneton and the DO be in terms of making bread, right?!
Then the results brought me down to earth! The bread was not bad in any way, but not of the level I had been achieving before. I am telling myself that it adds to the fun trying to figure out all these variables that are involved in making bread. Shows how even such a basic product has immense complexity.