The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

New oven 'build' preliminary results

kendalm's picture
kendalm

New oven 'build' preliminary results

Recently I posted the arrival of a new oven that I purchsed as a dedicated bread oven, and since then have been in setup mode and quickly realized this has become a project as opposed to a more plug-n-play scenario.  So with that, I am seeing some positive results and want to share them here.

This is a small 350g batard tester loaf to see how well this (relatvely) cheap import mini deck oven performs.  the oven I puchased is a 'xoeleo' from china manufactured primarily for pizza and as such has required some tinkering and tuning.  Danny ayo was kind enough to send me links to a seal for the door and www.brookbake.com dug up a rofco steam tray (despite them being out of stock).  To date I have applied a door seal but still seeing considerable leaking steam from some of the other seams in the body.  Despite the leaks I very surprised by the fast spring on this bake.  Another surprise is the paper thin crust on this loaf.  never had such a thin crust like this ever.  

Very little went into the preparation of this loaf - the bake was more a first 'wet' test (as opposed to dry steamless) test, in fact I originally did not even plan to load but rathet test the steam so this is a last minute loaf sort of thing.  Very interested to see whats next. 

 

Comments

DanAyo's picture
DanAyo

Do you think the copper based silicone will work to seal the leaking seams?

Test loaf looks great!

kendalm's picture
kendalm

I actually think now considering thr crust that enough steam was retained.  I used about double the recommended water dose and yes I think the silicone should work on the seams.  The question is whether there are more seams than I think. 

DanAyo's picture
DanAyo

Geremy, how do you like the ROFCO steam tray? It is nice a compact.

kendalm's picture
kendalm

Really neat device.  The instructions recommend 2 ounces of water.  I purposely double that to get a read on leaks in the oven, but as far as the steam tray, for an oven like this where there is no rack with a floor, this fits in with barely any compromise of deck space, so yeah, really like it ! 

 

Benito's picture
Benito

Geremy, would you mind posting a photo of the ROFCO steam tray, I’ve never seen such a thing.  Sorry I have no experience in a professional bakery so all this is new to me and I’m quite curious.

kendalm's picture
kendalm

This is a 'rofco' style tray.  Very thin so as to not compromise deck space.  Its very heavy as it contains rebar-like rods whose function is to store thermal energy.  At the top is a trough that drizzles water onto the rods and when water is poured in will rapidly convert most (if not all) of the recommended 2oz into steam.  I got this from brookbake.com - 

 

 

 

Benito's picture
Benito

Thanks for sharing that Geremy, that is a great device.  It would be nice to have that in a home oven or some version of that anyhow.

idaveindy's picture
idaveindy

I hope the steam tray doesn't block/restrict air space between the stone and the side wall.

Air circulation is necessary for both of the temp probes (upper and lower), and for even heating of the chamber.

--

I found out that the vents in a home oven, gas or electric, do more than vent moisture.  The positioning of both the vent(s) and the thermostat probe is such that air will circulate in the intended way, and the temp probe will give a meaingful reading.  

When we block vents/cracks/clearances, we change the internal air's natural/designed circulation, thereby creating hot and cool spots that the designer and manufacturer never intended.   If the temp probe then reads low, other areas overheat, because the thermostat doesn't "know" to turn off the burner/element.

This is not so bad in a convection oven with forced air currents. But in a non-convection oven, the design and placement of vents and the probe relies on the assumption that the vent remains open, as designed.

Not only the design, but the safety testing, is done with vents in a "normal" state.

kendalm's picture
kendalm

There is a vent consisting of 6 roughly 1/4 inch holes on the back wall near the ceiling (see image below).  seeing these as design elements clearly intended as vents I would not seal them.  Not sure if anything is really being obstructed by placing the tray against the side wall, but definitely hear you point about designed flow of gasses.  I may consult the folks at brookbake who are currently in the process of designing some intermediate home -> industrial models in the same vain as rofcos so I am sure they're knowledge of this subject is quite intimate.  very not interested in killing another oven ! 

idaveindy's picture
idaveindy

If I were doing this, I'd make sure the oven was on a heat-resistant surface/object, so it won't scorch your countertop.  

The lower elements will radiate heat to the lower shell, and the lower shell will then re-radiate a percentage of that heat downward.

kendalm's picture
kendalm

So check out this pic.  note that near the door gasket in the upper left and right corners I have applied some silicone in the small joint right above the corners.  I observed escaping condensation clouds here.  I think this small dab of silicone should correct that.  However, upon deeper inspection I noticed that inner chamber is built from individual sheets that are not flush and they should probably be continuous sheet that is folded rather than separate sheets flushing up against each other.  I noticed addition condensation cloud emerging from the outer body sides where there are vents (on both left and right outer shell).  This is a bit concerning but at the same time I recognize that the expanding gasses must have some small escape route otherwise the oven would build up a lot of presssure.  the question now becomes, can I contain enough steam ? 

 

kendalm's picture
kendalm

Its now apparent the steam containing nature of this oven falls short of hopes.  just did this bake wirh the recommended 2oz dose of water and got zero burst (see below). i think the burst from the loaf above can be attributed to the extra large cloud that I created.  The steam is just exhausting through the many seams of the internal chamber.  I am now sitting here pondering the idea of sealing the entire inside seams with the high temp silicone which otherwise I think would work but I am mostly concerned with the zones near the top elements that would probably experience temps above the silicone rating of 370C and to boot, the top areas are likely the most critical for trapping rising steam.  The other option is to go full on and disassemble the unit and braise with silver solder.  hmmmmm.  what now ? 

 

DanAyo's picture
DanAyo

Geremy, could it be something other than a lack of steam?

The oven cavity is so small, and with the Steam Tray (even if the oven leaks, like most home ovens) should that be sufficient? Why not put a cover over the dough or use a cast iron cooker to verify? You may be barking up the wrong tree.

What-do-ya-think?

kendalm's picture
kendalm

I thought the same thing this morning regarding a cover.  So far I did a few totally dry runs and got really hard thick crusted loaves.  the last two that I did were steam versions and you the first with the huge burst used a ton of steam and second no burst.  whats most perplexing though is that the crust in both cases is hardly caramelized.  they look dark but once cooled feel like a pillow.  that is to say, there is crisp at all, it feels like fabric.  Maybe there is as you suggest enough steam retention.  if i think about it like this - the cavity fills and expels the gasses due to expansion but would they really be replaced with dry air ? how would it be possible for an electric oven to replace the steam ?  perhaps if rising then dry air could suck in from below gaps etc.  also its important to note that I dont see a condensation cloud when I open the door.  

I think I agree with your plan here to do a covered bake in a dry atmosphere.  

One thing is for certain - the oven has plenty of heat retention.  The temp swings are minimal when the door opens. 

 

 

kendalm's picture
kendalm

My steam regimen with my old domestic had me plugging the vent.  It worked great, until of course the oven set on fire (eventually), but I don't recall ever seeing a condensation cloud.  its a mystery.  I also solicited some thought from doc dough. 

idaveindy's picture
idaveindy

From my engineering school days.... (before I dropped out)

"Dry steam", once it gets much hotter than 212 F, also called "super heated" steam, has no water droplets remaining. It is therefore invisible.

(Which is dangeous in a boiler room if there is a leak of invisible high pressure super heated steam, you'll get 3rd degree burns, and it can cut you open, or cut off fingers/hand.) 

 But I am unsure of which you want for bread baking purposes, wet or dry.

kendalm's picture
kendalm

in fact under 212F is not steam but rather condensed liquid water droplets.  what I mean is that steam (gasseous water) will form a condensation cloud when it hits room temp air ans so what I expect to see is evidence of steam as it exits the oven chamber.  I agree that steam is invisible it must eventually cool and condense somewhere presumably when it hits the air.  maybe it just slowly evaporates.  ugh my head hurts ! 

idaveindy's picture
idaveindy

If super-heated (dry) steam leaves the oven, and the sheet metal through which it passes is over 212 F, (or if the sheet metal does not cool the super-heated steam to 212 Degrees) you will never see a cloud.  And if the room is above dew point, the dry steam will just be absorbed as part of the air merely add to the humidity.

The exception would be if the dry steam is confined somewhere in the room, like if the oven is on a countertop, and cupboards are above it, and the steam is not allowed to circulate and dissipate.  then as the dry steam cools, confined, and then when the humidity reaches 100%, then water droplets will form somewhere.

I may not be explaining that right. But it's how I remember my marine engineering class, and the profs/teachers instilling a healthy fear of super-heated steam.  You'll hear it hiss, if it's escaping  high pressure, but never see it. 

kendalm's picture
kendalm

Specifically the part about steam simply hitting the air and then contributing to humidy, especially above dew point, which if your house is below dew point then you wont be worried about ovens etc.  I suppose a way to test would be to chill a glass and just hold it in the cavity for a moment.  ok making more sense now :) 

Doc.Dough's picture
Doc.Dough

Wet, low pressure steam.  Most systems that have external boilers operate at about 5psig. Danny ran into this with his external steam generator running at 10-15psig.

kendalm's picture
kendalm

during Dans initial experimentation.  Dan what happened to the loaves ? I seem to recall the problem being an over abundance of steam and you had to adjust valves and levers and maybe even added doc emmett brown's mr fusion (heh heh).  I think you maybe had damp loaves or something.  what exactly happened again ? 

idaveindy's picture
idaveindy

Looks like the top heating element came on. Or too much steam.

Maybe you super-heated the steam.

idaveindy's picture
idaveindy

Don't let, or unintentionally force, the steam to go where it normally doesn't go. It could short out the electronics.

I killed a cheap Emerson microwave by letting some hot/wet food sit in it too long after the cycle stopped.  Something must have got wet that wasn't supposed to get wet. When I next turned it on, "pop", and it was dead.

Benito's picture
Benito

The baby loaf really had great oven spring.  Did you get that thin crust with sourdough or is it commercial yeast?  It would seem your oven is doing well off the bat.

kendalm's picture
kendalm

Gotta say it was pretty fun to watch - it came up to size so quick.  its commercial IDY - nit quite ready to inveat too much time while tuning this thing. 

Doc.Dough's picture
Doc.Dough

Your test loaf has decent though light coloration, and with lots of oven spring is nice looking. Your soft crust after cooling suggests to me that it was not left in the oven long enough to dry out and the moisture from the crumb just softened the crust.  Crust thickness is (sort of by definition) determined by how deep into the loaf you find the boundary between fully dry and still wet crumb. I don't know of any reason why two different flours formed into similar loaves should have different crust thicknesses if baked in the same oven on the same cycle.  The mouth feel may be quite different if one flour is low protein and the other is high protein, but I would not expect a microscopic examination to indicate a substantial difference in depth of browning. 

Others have pointed out that excessive steam tends to suppress browning (I am just guessing here, but perhaps it interferes with the Maillard reaction) and may hold oven temperature low enough and long enough that the oven does not get up to caramelization temperature.

Keeping the steam in the oven is perhaps less difficult than keeping outside air from getting in. The pressure of the steam is not really higher than local atmospheric pressure. But diffusion will cause it to escape the oven if it has a path.

kendalm's picture
kendalm

Regarding time and pulling too soon.  Yes, and as a side note I neglected to mention that these loaves browned up so fast as in by the 10 minute mark.  As such I pulled both very early.  I think that would explain the fabric pillow crust.  Now regarding temps - there is no problem with heat and I can verify that by the internal analogue thermometer.  As a fan of really hot bakes I tend to jack temps quite high having previously used a gas domestic oven with a big door that will drop temps fast during loading.  And so, this routine of hiking temps I am beginning to suspect is a practice that may not be suitable here.  Even taking sweet time to load with this oven the analogue thermometer barely budges.  Even when the steam is activated, it barely budges.  

The strategy of using a steam tray like this seems to be one of trapping the gasses early on because the efficiency of the generator seems to be limited to about 10-15 seconds after which time the water has sucked much of stored energy and just kinda fizzles after the initial burst.  So yeah I agree that if a cloud is trapped then any evacuating steam is probabaly excess from the incredible expansion and it seems nearly inconceivalbe that a trapped cloud would be promptly replaced by dry air.  I think this is akin to how a bathroom after a hot shower remains humid even with the door open.  

Having said all that, I think its best to assume the steam is adequate and a. I'm going to need to control the bake time better starting at a lower temp and b. figure a better 2nd browning phase strategy.  a and b can probably be done by temp throttling.  

Still, that doesnt explain the non-burst exhibit.  perhaps its just proofing faux-pas as I must admit the bread part of all this has been a kinda neglected effort.  ok, more to come ... 

 

 

Doc.Dough's picture
Doc.Dough

Sounds reasonable.

I can't tell from the photo if we are looking at the oven heating element or a steam generator heating element.  The braided seal is probably not as tight as a silicone seal might be, but you have to be the judge of whether there are other leak paths for steam to escape or outside air to enter.

How big is the oven box?  And how much power does it draw from the mains?  I think I saw someplace that it was 240vac/single phase which in CA probably means 240vac with a neutral plus a ground.

kendalm's picture
kendalm

that I think you are referring to shows the lower elements with the stone removed.  Steam is done via a steam tray (which I just posted pics for benny above).  The inner box is 25'' wide, 18'' deep by abput 8'' in height.  As for power, gee - electricity is a mystery to me I just know its 220v at 50hz.  In think typically a domestic electric is 220v at 60hz.  

Yup there is still some leak at the braided seal but seem mimimal.  The outer casing has vents and they will puff condensation clouds and believe the route to these vents comes at the joins of the inner chamber.  imagine the chamber, 3 side walls, a ceiling and floor as separate sheets shored up against one another in such a way that your finger nail can fit in to the seams.  In other words, the inner chamber is not so much a pressed bent sheet but several fitting components.  Again though back to your point about dry air sucking in without a designed route for such flow, I am thinking it would be a stretch for a steam atmosphere once trapped to vent out and allow dry air to flow in and replace.  Compared to electricity I am more comfortable hypothesizing fluid dynamics ! 

 

idaveindy's picture
idaveindy

Barry has chimed in on several threads from people baking bread in pizza ovens, usually where the poster has burned tops.

Barry says he turns on the upper element for a couple minutes at the end of the bake  to brown the upper crust.

kendalm's picture
kendalm

I think that becomes an issue if you have the top elements glowing which in this case will happen when the top control is set very high (as in 600F+).  of course I don't intend going that maverick.  Counter-intuitevly its seems going lower on general temps seems the best course of action here since as mentioned, browning does not seem to be a concern.  

MTloaf's picture
MTloaf

In my limited experience I have found that humidity of some sort versus massive amounts of steam is all that is required and that is accomplished by having a good seal to keep it in( like a DO). My non convection oven will is so well sealed that it holds moisture even after the steam pan is removed. It came that way I have not modified it. If you need more steam to compensate for leakage maybe another Rofco steamer on the other side would do it. 

I was also wondering if it baked a decent pizza?

kendalm's picture
kendalm

well ... this is a really well shaped loaf that otherwise I think would bloomed quite nicely - dropped temps to about 490 and STILL these loaves are browning to this hue in 13 minutes.  burned botton the whole 9 yards.  Zero burst - hypothesis (again), caramelization happening too quickly.  I think I have this steam situation under control having sealed the inner chamber with high temp silicone and also having consulted brookbake folks on inner sealing strategies ... the horror....the horror ...

 

 

DanAyo's picture
DanAyo

Geremy, if you have an infrared gun shoot the stone and give us the temp

kendalm's picture
kendalm

I think it was about 530 by the time I pulled the loaf.  Also btw - so dang hot in there I baked with door open after 13 mins just to dry out the crust.  I will mix some more dough tonight and try to do a couple maybe even 3 bakes tomorrow.

If you think Im crazy - I want to ensure the steam tray gets nice and hot - it really needs to absorb a lot of energy to 'plume' so maybe Im just too used to jacking the temps on the gas domestic.  And the other thing is that this first loaf in this thread popped really nice at high temps.  who knows ? 

kendalm's picture
kendalm

Was sure this crumb would be foamy but hey - at least one thing worked.  As a side note - please observe the oval shapes of the bubbles, doc dough once PM'd and said 'are you stretching your loaves during the final proof'.  what a keen eye.  A habit sometimes and in this case - this is stetched just a tad about 10 mins into final. 

 

DanAyo's picture
DanAyo

Are you actually grabbing the dough in the couche and stretching it outward?

What if you raised the stone in your oven up an inch and a half or so to move it away from the lower element?

What is the temp of the stone?

Doesn’t the unit have the ability to control the top element and the bottom one independently? If so, what baout etting the bottom element a little lower.

kendalm's picture
kendalm

exactly my thoughts dan.  yes occasionally I couche the dough and realize I shaped a little short so I will kinda stretch it on the couche.  its bad practice but right now - eh big deal right.  the equipment is the focus ;) 

Benito's picture
Benito

Wow the crumb is gorgeous, you are going to school us all once you get your oven going.  Sorry it has been so frustrating for you Geremy, I’m sure you’ll get it sorted.

kendalm's picture
kendalm

Hey Benny - thanks m8.  Gotta say the baguette CB thread is chock full of amazing crumb results - if I recall recently you posted some epics.  I think its all about crontrolling the yeast and good gluten development.  Too bad getting bloom on these loaves is really twisting my melon.  gotta sort that out so we can put the canadian flour through the ringer ! 

Benito's picture
Benito

Yes I am very interested in getting your feedback about what Canadian wheat you feel is good for baguettes.  Unfortunately the availability of flour is spotty although improving.  Every time I get a few bakes in with one flour, it goes out of stock all over the place.  My current flour has been good but it is gone from the stores.  I have found some flour from Quebec that is also only 10% from La Milanase that I’ve heard good things about, so I will be giving that flour a go soon.  

Looking forward to your baguette bakes in this new crazy hot heat retaining oven.

kendalm's picture
kendalm

Once I see gringe to my satisfaction will bust out the Canadian stuff.  I'm hesitatant at the moment considering this is an ancient grain and probably work best as a blend - 

kendalm's picture
kendalm

Not the film about wine - the pics - argh sorry Benny :\ 

idaveindy's picture
idaveindy

Did you have the upper element on at all during the bake?

kendalm's picture
kendalm

The oven seems to really retain heat.  I fire it up as soon as I start pre-shapes in order to get the steam tray fully heated (this is per Rofco advice).  Then drop the dials (both upper and lower) a just enough to switch off the elements.  They may click on momentarily but not enough get to that very red glow - maybe the top goes dark red for a minute.  

idaveindy's picture
idaveindy

"Then drop the dials (both upper and lower) a just enough to switch off the elements. They may click on momentarily but not enough get to that very red glow - maybe the top goes dark red for a minute. "

There's the problem.

We've dealt with this phenomenon with at least a half dozen foreign guys baking bread in a pizza oven. Overly done tops. And they all used the top element, "just a little."

As I've speculated, and barryvabeach confirmed (he has a pizza oven):

the top element needs to be completely/always off from the time you load the dough, until the end of the bake where you might turn it on just a minute to brown the crust.   (Using the top element to pre-heat is okay. )

It's the "radiant" heat that does it, as it is much hotter than air temp. The thermostat registers air temp, not radiant heat. It's like your car getting 150 degrees hot in the sun when the air temp is only 85. The radiant _sunshine_ gets it hot, not ambient air.

Those elements radiate a temp around 900-1200 F, so even a few seconds darkens the crust.  And once a little dark, the crust absorbs heat quicker, as a black car versus a white car in the sun. (as Barry also explained.)

 Verify with barry.  You're having the same problem he did.

kendalm's picture
kendalm

Ok - the upper goes off.  temps down etc.  Btw Ive heat gunned the elements and recorded high 700s F.  And btw - 12 hours later the deck is still 120F.  This is so not what I am used to but funny thing is the loaves are cooling down and becoming very soft.  I just have to get the bake time to a normal 18-20 minute length as opposed to feaking 12-13 mins.  Thats just wild but its so counter-intuitive to not have hard loaves.  More to come ... 

idaveindy's picture
idaveindy

last time this was discussed:

http://www.thefreshloaf.com/node/64854/deck-oven-problems-steam

Though he was doing full loaves, not baguettes.

Ciabatta and barry had good comments.

DanAyo's picture
DanAyo

Don’t feel like the lone ranger. It is common for bakers first using the Rofco go through similar adjustments. I know Kat had to work to get her Rofco dialed in.

kendalm's picture
kendalm

He's a genius baker - go look up 'Round River Bakery' in idaho.  So it was kind of expected from th me get-go.  Now one would think that such a fast bake would produce a hockey puck loaf.  Even this last baguette when pillowy after an hour of cooling - ok time get some dough primed.  

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