The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

A protocol request re: steaming

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bnom's picture
bnom

A protocol request re: steaming

Much information has been generously shared on TFL about people's experiments with introducing steam into home ovens.  However, more often than not, there is no mention of the type of oven (gas or electric) one  is using in these experiments.  The same holds true for books like BPA and Bread.

From my own personal experience and from hearing about other's experience, I can say that what works in an electric oven may not work in gas (for example - Sylvia's towel technique worked great in my electric but poorly in my gas oven).  Having switched to gas recently, I've been combing these pages for steaming techniques that will help me get the same grigne and crust I used to enjoy when cooking with electric.  It's been a little frustrating because I don't know whether the technique recommended was tested in a gas or electic oven (or both).

Therefore, my request is that when people post their experiments or suggestions related to creating steam in a home ovens, to please specify the type of oven (gas or electric) they are working with. 

Much appreciated!

 

thomaschacon's picture
thomaschacon (not verified)

Water phase changes to a gas at 212 F / 100 C (STP).

Any oven, gas or electric, would be well above that temperature, so steam should not be affected.

Having never baked in a gas oven, I bet I'm missing something obvious.

 

wally's picture
wally

My home oven is gas.  It therefore vents continuously to supply oxygen to keep the gas lit.  However, I've had fabulous success using SylviaH's towels in boiling water method.  Her method will ensure that there is a constant source of steam for as long as you require.  Now, I gin it up a bit in that I also have a cast iron frying pan in the oven's floor filled with lava rocks.  After loading loaves I will throw a cup of hot water on the lava rocks immediately, another cup after 1 minute, and a third and final cup after another minute.  One other note: I put the pan of water with the towel below rather than above my baking stone.

If you want to see the results just look up Wally's blog.

Good luck - those grignes are attainable in a gas oven!

Larry

thomaschacon's picture
thomaschacon (not verified)

Knowing that, I have an ideal solution: Sell the gas oven. Buy an electric one. :D

bnom's picture
bnom

I love my new gas range but if I'd known the difficulty with steaming I would have gone gas stovetop, electric oven. Too late now - I expect to be buried with this thing (please, no cremation jokes).

@ Larry - I've done the wet towel thing three times now (top and bottom racks) and get the same result - pale, chalky crust color.  I've had the same crust color issue when I used boiling water over lava rocks and spritzing.  Why????  Will continue to post my experiments on the thread I started some weeks ago.    

 

wally's picture
wally

Without seeing pics and knowing more I can't do more than speculate. Paleness can be a result of a temp too low or of use of a poolish that is over-ripe, e.g.

Larry

gary.turner's picture
gary.turner

If you're not getting good crust color, it is indicative of not enough time at a high enough temperature. Are you removing the water source when steaming is supposed to end? If not, the water will continue to absorb heat from the oven as it changes state from liquid to vapor. This means the transition is trying its best with the rate of change to hold the air and water temps to 100℃/212℉. Once you remove the water, your oven will need to recover, much as it does when you start the oven to preheat.

Browning is due primarily to the caramelization of sugars in the dough and requires 160℃/320℉ for sucrose and glucose and 180℃/356℉ for maltose. But,  even the dough is affected by the heat of vaporization, the surface temperature being held down as  the dough moisture migrates to the surface and evaporates. I've measured the surface temps at 240–245℉ 20 minutes into a 30 minute bake in an unsteamed 375℉ oven. As you might guess, browning wouldn't even have started yet.

So, watch the oven's actual temperature, measuring near the loaf. You may be surprised.

cheers,

gary

n.b Larry mentions an over-ripe poolish, which would imply a shortage of sugars to caramelize in the first place. Worth a mention is the overly sour leaven. Caramelization happens best at a neutral pH. Above 9 (alkaline)  or below 3 (acid) slows the process substantially. ~gt

bnom's picture
bnom

Here is pictorial evidence from yesterday's bake.   Same dough (Hamelman's Vermont SD with Increased Grains) and proofing times. 

This first loaf was cooked inside dutch oven for 12 minutes and then taken out to finish browning on the stone (no steam and convection fan on).  As you can see - there's no issue with maillard reaction:

The second was loaded onto the stone in a 500 degree oven . 1 cup of boiling water was added to a tray of preheated lava rocks under the fibrament stone.  Water was spritzed on oven walls.  After 10 minutes (it's a small boule) the oven was turned down to 460 and convection fan turned on (lava rocks were left in because water had already evaporated.  It's not that there was no maillard reaction, but in the unslashed areas, the crust has a pallid, dusty quality (the loaf actually looks better in the photo than in reality). 

I've done similar experiments (same dough cooked using different approaches). The breads that have looked most pale are the ones where I used Sylvia's wet towel approach (which is what I used to grand effect in my old electric oven).  In those experiments, I've removed the steam tray after 10 or 12 minutes.  Maybe I need to take it out much sooner (after 5 minutes).  Obviously, I still need steam to get grigne -- but it seems like too much steam impedes crust color.   Your thoughts?

PiPs's picture
PiPs

From all the reading I have done I would still say your gas oven is venting the steam your require .... I don't understand how or where the steam is being vented in those systems but could you try turning the oven off for the first 5-10 mins of the bake when you are steaming and then switch back on the remainder as normal convection?

Cheers,
Phil 

bnom's picture
bnom

Okay, next time I bake I will try turning off the oven for the first 7  minutes and blocking the exterior vent with a towel. 

 

thomaschacon's picture
thomaschacon (not verified)

I read mine recently and found all sorts of neat programming tidbits that let me modify how the oven works.

You might find something (a programming setting?) that'll help you with venting, etc.

If not, call the manufacturer's customer service line. They might be of some help. (They might also hear what you have to say and respond, "No, it shouldn't have that result. It sounds like your X is broken and will need repair.")

-

You might need a geek's help, as the programming incantations are no better than any other electronic device: "Press this button twice while holding these two buttons, then stand on your head, juggle three apples with the toes on your left foot for 12.5 seconds, then press the big red button to make the oven do this." If you thought VCRs were hard to program, wait until you try programming your oven.

bnom's picture
bnom

One of the reasons I bought this range (other than the fact that all four open burners cook with 23,000 BTUs) is that it does  not have electronics that can go whacky with steam.   I may just contact the fellow who developed this stove to ask him what I need to understand and tweek to get the results I want. 

gary.turner's picture
gary.turner

In the second loaf (the pale one), I see every evidence of the crust's temperature not reaching the required degree.  Did you measure the temp of each loaf's crust with an IR sensor?

I suggest the following mechanisms in the two cases:

In the DO method, the oven itself stays very hot, transferring heat to the DO, which heats the loaf, driving out the moisture which keeps the surface of the loaf soft. Once the lid is removed, the little bit of steam within the DO is rapidly dispersed throughout the oven with little lowering of temperature other than the heat lost by opening the door. The high heat of the oven and DO quickly dries the crust and begins caramelizing its sugars.

The water tray steam generator must absorb heat for the vaporization. This causes the water to stay no higher than 100℃/212℉. The absorption of heat by the water draws down the temperature of the oven itself, i.e. the air, walls, and the baking surface/container. Once the water has evaporated or has been removed, the oven must recuperate. Enough heat must be added to bring back up the temperatures of the air, walls, and baking surface to the desired degree. Until then, the loaves' surface may not dry. Until dry, caramelization cannot occur.

It is my conjecture, completely unsupported by empirical evidence (kinda like the whole global warming scam), that baking in a DO will drive more moisture from the dough, leaving less in the crust needing to dry than will baking with a steam pan.

cheers,

gary

bnom's picture
bnom

I very much appreciate your giving me your take on this.  It makes sense.  I haven't tested the crust temperature - just the internal temp (205 degrees). What temp should the crust be? 

If your right and the problem is heat being drawn down by the steam - can you suggest a solution that doesn't require a DO type set up (I'm thinking of baguettes). 

 

 

gary.turner's picture
gary.turner

The surface temperature should reach the 180–190℃/356–375℉ mark as the optimal caramelization temperature range. When your steam time is done, vent the oven. Opening the door for a moment should do. Be sure the steam tray has no water left, else be sure to remove it. Then, shut the door, give it a minute or two and lower the temp to about 246℃/475℉. Bake until the color is as you like it.

cheers,

gary

bnom's picture
bnom

Gary, thanks to you, I had the most hopeful results yet in my new oven.  I made Hamelman's Vermont SD with Whole Wheat (and avoided my usual temptation to increase hydration). I heated the oven to 500 and loaded two loaves at the same time.  I added boiling water to a pan of lava rocks and then did the ice cube drip onto lava rocks in a seperate pan (both lowest shelf).  Per your suggestion, I turned off the oven and covered the vent with a towel.  As you can see in the photos,  one loaf got exuberant oven spring and grigne. The other didn't have the oomph to break through on the slashes. Both had a nice golden color.

Thanks so much for the suggestion Gary. If you or others have ideas for how to achieve te same results for BOTH loaves, I'd love to hear them.

 

PiPs's picture
PiPs

Another comment regarding ovens ...

Fan forced ovens (convection) that don't have the ability to turn off the fan and bake as a conventional oven are also a headache for home bakers. The fan quickly dries the crust interfering with oven spring and ideal colouring. I am unable to turn off the fan on our oven so I must preheat the oven with two stones for extra mass and then turn it off after loading the bread and steaming (I use ice on a cast iron pan with nuts and bots) I hold the door shut tight for ten minutes or until the temperature drops to 200C on the oven thermometer I have hanging below the stone. I then switch the oven back on and bake as normal at 200C for the remaining time.

Cheers,
Phil

 

Yerffej's picture
Yerffej

Gas ovens vent a larger quantity (by far) of air than do electric ovens.  The gas flame needs all that oxygen to burn.  This does not mean that you cannot get good steam in a gas oven.  Follow Wally's advice and put a large cast iron frying pan on the floor of the oven,  before you turn on the oven, and give it hot water (10 ounces or so)  immediately after putting your loaves into the oven.  This initial "blast" of steam is crucial to improved oven spring.  You want as much steam as possible right at the beginning of the bake.....after that, relax.

Happy Baking,    Jeff

Doc.Dough's picture
Doc.Dough

For an average 2.5 cu ft oven it takes about 2.6 oz of water to fill the oven with steam.  But the issue here is the loss rate of the steam and the source of makeup heat.

I think Jeff is absolutely right that for a home baker the answer is probably to turn off the oven for the few minutes when you need to keep the steam in the oven and depend on some amount of thermal mass to hold up the temperature while the burner is off and the steam is doing its job.  Then you turn the gas back on and let it do its job.  What I don't have a good handle on is how you really prevent the loss of steam through the normal vent sysem due to free convection while the gas is off.  It seems to me that you would want some kind of a damper that you could shut to keep it in the oven.  But you would have to have a safety valve incorporated to prevent the gas from being turned back on while the damper was closed.

The steam generator for a gas oven probably needs to be substantially larger than that for an electric oven (by a factor of 3 to 5 and maybe larger) to make up for the high leakage rate. This may be the reason why commercial deck ovens that are fired with gas have the burner and the exhaust products in one chamber and the bread in another that is thermally connected but where the combustion gasses flow out through their own flue and not through the chamber where the bread is baking.

Mini Oven's picture
Mini Oven

a cover seems to help many with fast venting gas ovens, saves messing with all the steam.  One of TFL's oldest threads (qahtan)deals with the subject including how to make your own from a clay garden pot.  So does this updated one:

http://www.thefreshloaf.com/node/10477/homemade-cloche

Other methods include roaster lids and all sorts of pots and bowls inverted over loaves.  The top to a table top round grill is also an option.  Remove all knobs that can burn or melt and replace with metal knobs and grips.  

thomaschacon's picture
thomaschacon (not verified)

Another use I read about yesterday: How to Make Your Own Tandoori Oven

(One thing I lament about moving to Colorado is the dearth of Indian/Pakistani restaurants. I'm tempted to build my own (Tandoori, not Pakistani restaurant), but then I'd have to put on body armor to deal with the Home Owner's Association Crazies. I should just buy one of these, put it in the foyer, and disable the fire alarms. Naan requires sacrifice!)

bnom's picture
bnom

Cook's Illustrated magazine this month (last month?) had an article on making naan at home. After much experimentation they found that naan works best cooked on a cast iron pan on the stove top.  I haven't tried that and don't have the magazine but you may want to check it out. 

fminparis's picture
fminparis

I use the water content of the bread to steam itself.  For boules, I let the dough rise on a parchment covered cookie sheet. To bake, I cover it with an inverted enamel pot which I remove later on to allow the crust to finish crisping. I never found a difference between a cool pot or pot heated in the oven.

For baguettes, I purchased a thin sheet metal open box custom cut and bent to just fit the cookie sheet  the bread rises on (www.metalbytheinch.com) and just slightly higher than the baguettes will end up. I cover the baguettes with that box to trap the steam and then remove it later on to allow the crust to finish crisping.  That company will cut and make the bends for you according to your specifications.

The steam coming from the dough and trapped under the pot or box is all the steam you need for a great, crispy crust.

 

bnom's picture
bnom

As you can see by the photos I posted above, the beest loaves I've made since switching to gas are those cooked in Dutch Ovens. But I like making baguettes so I've been trying to avoid going that route.  I did purchase some long aluminum steam tray inserts that will cover my 30" stone in the hopes that it may work with baguettes. I haven't tried them yet. If they work, it would be a cheap alternative to you custom metal cover but if it doesn't, I will definitely go that route. 

Do you have pictures you can share of your baguettes?  Are you getting good grigne?

 

RFMonaco's picture
RFMonaco

Get the new long clay baker from King Arthur Flour.

http://www.kingarthurflour.com/shop/items/long-covered-baker. Superb. 

All at Sea's picture
All at Sea

... placing the long clay baker you've linked to,  in to a cold oven. I've never actually had the bottle to try that with my makeshift DO.  But might give it a whizz.  Many thanks for the link, RFM.

Janetcook's picture
Janetcook

Caution...

Just a word of caution when experimenting with new steaming techniques....

This past fall I was experimenting and ended up getting steam burns on my face that were quite painful and took about a month to heal.  My face is still sensitive to heat when I load and unload breads.

So be careful and stand back when adding hot water and when opening oven door to add more steam.  

Good Luck solving your problem....always something to adjust to when making a change.

Take Care,

Janet

 

pjkobulnicky's picture
pjkobulnicky

My move to gas from electric was equally difficult until I simply upped the temps about 50 degrees for those slack-dough loaves that required oven spring and browning.

I will agree with Mini that my batch of cast-iron dutch ovens still work the best.

bnom's picture
bnom

I've been preheating for an hour at 500 degrees.   The oven make great pizzas.  It seem the only issues I have with browning are when I'm trying to add steam.

All at Sea's picture
All at Sea

... only a problem with high hydration doughs? Or any dough?

bnom's picture
bnom

I have to say it's been with high hydration doughs.  I've made rolls, pizza, etc. without problem.  The bread pictured below   was Hamelman's Vermont Sourdough which is a lower hydration dough than I generally make -- it has been the most successful bake so far but I attributed it more to steaming technique (see my reply to Gary above) than hydration.  Please let me know your thoughts on why higher hydration doughs would be more problematic. 

All at Sea's picture
All at Sea

Hi Barbara ...

I have developed a similar issue as you - I have a gas oven and recently very poor crust caramelisation. It wasn't always this way; but lately things have got worse. Back home, in my electric oven, there is no problem at all. But when I used to use, like you, a DO in the gas oven, problem didn't exist. Lovely brown crust; lovely grigne, ears etc. etc.

As already mentioned, the key seems to be the venting issue with gas ovens. But remember, it not only vents out, but must, therefore, be drawing in air all the time. Our air here is very humid - 85-90% humidity norm. So, the oven is, in effect, drawing in moist air all the time. Combine that with a high hydration dough (in my case I've been increasing the hydration as I've got used to handling it, and used too, to the lovely crumb it produces) and it could be there is just too much moisture inside and outside the dough - not just at the steaming stage - but throughout the entire bake. An electric oven would not be drawing in air throughout, so the moisture is driven off and taken out of the oven when you open the door to faff with the removal of lava rocks or steaming towels or whatever. In an electric oven, the residual air, will then dry and your crust caramelise. But if your gas oven is forever cycling fresh moist air in and venting it out, then it's going to be harder to dry the crust sufficiently with a high hydration dough.

Must emphasise: at this stage, this is just a theory, - recklessly unfettered by science, but it might be worth pursuing.

You said in one of your posts above:

"and avoided my usual temptation to increase hydration"

Perhaps, then, the key is to use a lower hydration and see how that affects the colour of the crust. I didn't have this problem with my gas oven, to anything like such a degree when I used to bake with hydrations around the 65% mark. But at 75%-80%, without a DO, my crusts have become a thing of abject insipidness!

Those who bake successfully with gas without the use of a DO, I wonder what hydration levels they are in the habit of using for their breads?

Lastly, if you are in a high humidity locale, it might be, that like me, the air being drawn continuously into your gas oven is just overly moist and with a high hydration dough, the air inside and around your cooking dough, is just too damp for proper crust colouration.

My plan, anyway, is to put this to the test by baking a loaf with only 70% hydration; and then one with only 65% and see how this affects the crust. I love high hydration doughs; there's something very rewarding and satisfying coaxing them into billowing clouds of open-crumbed lacework, but without a decent crust, the party is somewhat dampened!

All at Sea

Doc.Dough's picture
Doc.Dough

Humidity is a meaningless term when it comes to baking bread (though it means a lot when you are proofing). The parameter that matters is the dew point.  Even if you live on the shore of the Red Sea, the ambient dew point won't rise above the  dry bulb temperature.  The world-record high dew point of 95°F was recorded at Dhahran, Saudi Arabia, and when combined with that afternoon's temperature of 108 produced a heat index of 174 degrees.   While that is hot, in an oven where you have live steam (or hot rocks and water), the dew point can be as high as about 210°F (in theory 212°F, but not in practice).  In a humid city like Dhahran, at 108°F with a dew point of 95°F (67% relative humidity) the weight of water per pound of dry air is 0.036 lb/lb.  In an oven at 450°F and a dew point of 210°F, there is 15.69 lb of water per lb of dry air (the relative humidity happens to be about 3% which you might otherwise think was pretty dry) and it is the almost isothermal condensation of that water on the cooler dough that cooks the surface so quickly.  So no matter how much "humid" ambient air enters the oven to support combustion (the stochiometric ratio is around 17:1 for natural gas so you need about 17 lb of air to burn 1 lb of gas), it will not raise the dew point in the oven.  In fact it dramatically reduces the dew point, which is why shutting off the gas and blocking the vent works.

 

bnom's picture
bnom

If you haven't tried yet the suggestion to shuff off the gas and block the vents, I recommend it.   Doc.Dough seems to have ruled out the issue of ambient humid air entering the oven.  If the only change in  your breads have been an increase in hydration, that would certainly seem to be the next tweak.  The good news is that you can still achieve a nice open crumb without having to go with a very high hydration. 

All at Sea's picture
All at Sea

... and onwards! Am chuffed to report a crust-up for the better yesterday. Hadn't read your post then, Barbara, so didn't attempt gas shut-off and vent block, but will do next bake. Have you found a big improvement this way?

So without that solution, I thought I'd best start a process of elimination.  Not enough steam most likely? So I had another go at using Sylvia's wet towel technique. This time, however, I placed a roasting dish on the rack underneath the baking stone, and fired the oven till it was 450 degrees F - as hot as it gets. Then with a loaf ready to bake, removed roasting tray, dumped in folded tea towel and poured kettle full of boiling water over it and returned to oven - along with the bread. Slammed door shut and left it to do whatever for 10 minutes. When I opened door to remove the towel and roasting pan, the loaf was oven-kicked into bucksome, blowsy airiness, with expanded grigne and a goodly ear.  It took another 35 minutes to colour up, and it wasn't as dark as I think you would like, but it was a huge improvement on the wan and weasle crust efforts of late.  For what it's worth, the first time I tried the wet towel trick, I used a much thicker towel and I don't think I had the pan as wickedly hot as this, so it was an abject failure. But this time, it really helped, I think. And this last rather happier event was still with a dough of 75% hydration (that's another dumb theory - reduce hydration for gas ovens - now proving it can't swim!)

Do you retard your shaped loaves prior to baking? That was something else that had me wondering. This time I went back to my old habit of retarding them, and walloped them in still cold from the fridge.  Does that help crust colour and oven kick, too? I'm a little shy of suggesting such stuff since I'm not having much success with theories of late ...  (!)

The other thing I read recently is - and I think this has been mooted here before - gas is a "wet" fuel. Creates a wetter atmosphere than electric. And I've also seen several other TFLs bemoaning their crust problems on changing to a gas oven, so it might well be an issue if you're used to electric.

Anyhoo - feel somewhat chirpier, but only if I can repeat yesterday's success  will it be any indication of solid progress!

All at Sea

bnom's picture
bnom

Sounds like you made excellent progress on your last bake!  It is heartening is it?  It sounds like you got enough steam to let the loaf bloom.  As for color, retarding should help hastening the maillard effect.  That it took so long to take on color may be the result of the relatively low temp of your oven.

Regarding the use of boiling water on the towels -- that's what I used to do with my electric but I read recently (I think it was a post from Sylvia) that your towels won't be as hot pouring boiling water over them as they will with microwaving.  So that's another variable you might want to tinker with.  Also, do try the oven off/vent covered routine. I'll be interested to know if it makes much of a difference.

Post photos if you can. . ..

So, do you do your baking on a boat?

All at Sea's picture
All at Sea

... for taking the time to explain. Blaming soggy sea air cycling through oven sounds remarkably doolally, have to admit. Rest assured, abject theory rapidly dumped overboard.

All at Sea