Slashing Effects on Oven Spring?
These two loaves were treated identically through bulk proofing. They were divided into exactly equally portions (737g) both Preshaped, within 30 secs, rested 15 minutes, shaped, proofed, slashed, and loaded into the oven within one minute of each other. They were Baked, rotating the loaves positons in the oven--after steaming--and removed within a few seconds of each other.
As you can see in the photographs there is a significant difference in the oven spring realized in each loaf. Three things may have effected the difference.
1. I may have tightened the surface skin on one tighter than the other.
2. I turn off the convection mode during steaming; consequently one side of the oven may be hotter than the opposite side.
3. The different slashing patterns restrain or encourage the oven spring upward.
I'm going to repeat this event, as best I can. (This is our weekly, go-to sourdough bread). I will repeat the different slashings, and reverse the loaves' positions in the oven. Otherwise, I will keep all things identical as best I can.
I've had a recent experience with crust bursting on another bread (entirely different, Jewish Rye); it sensitized me to the effects of slashing, although I've wondered about it in past baking, but I've never experienced such a side-by-side difference.
I'll post the results when I do it again.
David G
Comments
David, when you do this again it would be interesting to see the loaves after you slash just before going into the oven. They both look like they had good spring and I'm a little surprised at the one that blew up so high. The slash pattern explains that growth but , so much. They both look like good breads.
Eric
Take a look at my reply to hutchandi, below. I'll post before and after baking shots.
Thanks for you comments. Like you I was surprised by the degree of difference.
David G
Besides the fact that you are nitpicking yourself over two perfectly fine loaves, you are also comparing apples to oranges, as you have two totaly different scoring patterns. Not identical at all, the pattern you used on the right will always allow for the expansion in the upwards direction, while the parallel slits on the left loaf always tend too produce a rather oblong loaf with somewhat less potential for great hieghts. The expanding dough does not automatically move upwards, it moves in the direction of least resistance.
That was my point for this blog post. I believe the difference is caused exactly as you described, but there are still the two other possibilities that exacerbate the difference. Moreover, the difference seems to be in all directions, both vertically and horizontally.
David G
I really don't see how you will be able to extract very meaningful results by experimenting in this manner, with scoring differences like you are using, it will be difficult to weed out any other variable. Shaping technique and oven deficiencies would be better tested using identical scoring.
First of all this wasn't intended as an experiement, I was just baking bread. Reading your post, I immediately saw your point. Recently, I started manipulating my oven modes. I preheat in convection mode, load and steam for 5 to 15 minutes with the oven in conventional mode (this turns the fan off). I remove the steam source, vent the oven, and finish baking again in the convection mode. I have only baked baguettes, batards, and torpedo shapes since starting this oven regimen. All those loaves were loaded spanning the oven. This is the first bake I've loaded loaves side by side.
My first step will be what you're recommending: two boules, identically slashed, loaded side by side. If I final shape as identically as I can this should point out any side to side heat gradient.
I'll do this when next I make this formula--a week to ten days from now. I bake for fun, flavor, and our daily bread, not to do experiments. However, sometimes my curiousity gets the better of me. Remember that old saying, "When you're up to your butt in alligators, it's hard to remember you set out to drain the swamp!"
David G
They both look very good ! I'd be interested in knowing your recipe if you wish to share it.
I call this 010110 Sourdough, because it's a variation of Halcyon Acres (our home) sourdough, and I worked it up on January 1, 2010 (010110). And, I like that its name looks geekily binary;-)
Final dough Wt. 1500g
Hydration % 68%
Starter Wt. 500g
Starter Hyd.% 100%
Total Flour Wt. 885g
Total Liquid Wt. 600g
Flours
Starter 250g 28% Note: Starter was fed entirely with first clear flour
Whole Rye 85g 10%
All Purpose (KA) 275g 31%
Bread Flour (KA) 275g 31%
Total Flour Wt. 885g 100%
Fluids
H2O from St'er 250g
H2O 350g
Hydration% 68%
Salt 18g 2%
Mix all but salt to well incorporated shaggy mess, autolyse 30 minutes. Add salt and incorporate. French Flold until dough no longer sticks to work or bowl surface. Place in oiled container. Do 3 Stretch & Folds at 20 minute intervals. Continue bulk proof an additional 30 minutes. Divide dough into two equal portions, preshape (boules or your choice), rest 20 minutes, shape. Final proof until loaves pass poke test (approximately 2 hours if your starter is very active, longer if necessary.)
Note: I refresh my seed starter with first clear flour, and, in this case built my formula-ready starter also with first clear flour, but any flour is acceptable. However, I'd use either Whole Rye, or a 50/50 mix of AP and Bread Flours. If I used the Whole Rye I'd eliminate the 275g of AP flour and replace it with Bread flour. I'd do that because we like our crumb chewy.
I preheat the oven to 550°F, pre-steam for five minutes, load slashed loaves, decrease oven temp to 450°F immediately. Remove steam source after 15 minutes and vent oven. Continue baking until done (hollow sound, or 205°F Internal). Cool completely.
Enjoy.
David G
Another interesting comparison is not to slash at all, and when the dough is clost full proof it is sometimes best not to slash for fear of the loaf dropping right back with a collapse.
regards yozza
It's nearly a year now since I went on this quest to improve the skills I had, and learn new ones re bread baking. I've never had a loaf deflate. I have had loaves that didn't get much oven spring, but no bricks yet. Slight underproofing is probably my most often mistake.
Also, I've never baked a boule, batard, or baguette without slashing. I'm a member of the "You eat with your eyes first club." Besides their utility in encouraging oven spring, I like the patterns. Shiao-Ping, and Bread-Cetera are among my heros for eye-appeal loaves.
David G
Just kidding... :)
I gotta keep that palm/hand slash design handy... I don't want height.
I now know it refers to one of the many different crystal structures steel, and its alloys develop depending on how they are heated, cooled, forged, and worked. I bet I've encountered the stuff in my past, but knew it by some alloy number. I'm glad you pointed it out to me.
And, you just might be right! It's the bowl's fault! ;-)
David G
Nice illustration david,
Beautiful boules! Don't tempt me into White bread..
I've made this formula building my starter with either Whole Wheat flour, or Whole Rye flour then scaling the remaining flours to reach 40% whole grain flour, but we like relatively open, chewy crumb, so I rely on AP and/or bread flour to provide a strong gluten framework.
Frankly, I've carefully examined the nutritional value of different flours. White flour is clearly at the low end in some important nutrients, but I don't see anything unnatural, or harmful in unbleached white flours. I think its a bum rap.
David G
Hi Dave,
It looks to me as though the total expansion area of each of your two different scoring patterns isn't that different. The left boule is more dramatic, but are you sure that the final volumes of the two loaves are so different? FWIW I prefer the right loaf...
aloha,
Dave Hurd, Hilo, Hawaii
the boule on the left has unquestionably more volume. The only way I know, however, to be certain is to immerse them in water in a cylinder, or any regular shaped container until their highest point is just even with the surface of the water, then measure the water heighth change, and calculate the volume.
I'm certain, however, this test would change the flavor, not to mention the loaves' keeping power ;-)
Regards, Love your home state.
Davidg G
Even if the total expansion area is exactly the same, these patterns are totally different and would make a big difference. While the left loaf has virtually no place to go but up, the loaf with the long finger slashes has alot of area to spread sideways while being restrained from moving in the upward direction by the strips of more stretch resistant outer cloak. The following sketches hopefully show how this will spread the loaf outwards while hindering upward expansion.
In an unscored loaf, expansion is basicly uniform, and if gravity were not a factor, a round ball of dough would simply become a larger version of itself.
Add parallel slashes and you not only allow for expansion, but also restrain the upward rise by sort of caging the soft inner dough within leathery prison bars.
This results in not only expansion outward from the open slashes, but the expanding dough also pushes sideways against the scored edges of the harder crust forming on the gluten cloak, further spreading the loaf out to the sides.
This inevitably results in an oblong loaf. This actually is the method I choose if I desire to create a somewhat longer and uniform loaf more suitable for sandwiches, but proofed in a round banneton.
I've noticed this phenomenon before, but only observed slashing influence on shape. For example, the palm slashed loaves most often assume a triangular shape, and is explained by your third illustration. I think someone (you?) should write an instructive post that helps us all understand the influence of various popular slashings on a loaf's final shape. I don't think its at all intuitive for the more complex slashings, e.g., I am still amazed at the leaf-like pattern properly slashed bageuttes develop when they influence good oven-spring. Intuitively, I expect something long and narrow, much like the center slash in the palm slashed loaf we're discusssing.
Thanks,
David G
Thanks for nominating me David, but I probably would not be the one to do this. I like doing illustrations, I am a CAD technician by profession not a baker, but many of the projects I have worked on involved solving for movement and expansion of structures not related to bread. I don't really get into allot of fancy scoring on my breads. I just do what works, and that sometimes means not scoring at all.
About the "leaf pattern" on the bauettes not being as you expect...see my red arrows pushing at the eges of the slash? A baguette gets more of a short slit cut into it, and the arrows of expansion naturally open the slit like a leaf or eye, and also push the surrounding cloak build up into the somewhat dramatic "eyelids" which can be made even more dramatic by scoring at an angle or by using the curved lame, these methods actually allow for an accordian like expansion, if that makes sense.
How long did you preheat the stone? Did you have your steam container centered, above, below the bread? To me the size difference doesn't look slash related.
Greg
Didn't intend to preheat it that long, but the kitchen temperature was 67°F, and it took the loaves longer to proof than the usual 1.5 to 2 hours.
I generate steam with a wet towel covered sheet pan, centered on the rack immediately below the stone. I've experimented with it placed on a rack above the stone. Below works best. Also, I'm convinced the steam distribution is homogenious throughout the oven.
David G.
I'm with Greg. I don't think the different scoring patterns alone account for the different oven spring.
I'm guessing that the loaf on the left (with the greater spring) was loaded first. It was placed further from the oven door. It was furthest from your steaming apparatus.
The first loaf that hits the pre-heated stone gets the most benefit from the hot stone. Once that loaf is loaded, the stone isn't quite as hot. In addition, the re-opening of the oven door to load a second loaf (if that's your procedure) cools things further. If steam hits the bottom of the stone, it's evaporation cools the stone locally, usually under the later-loaded loaf. That's my reasoning.
My understanding is that it's the directly conducted heat from the stone that has the biggest impact on oven spring.
I'm eager to see you bake two more boules with these scoring patterns, but reversing their placement (in both time and space).
David
P.S. I forgot to say that I think both loaves are gorgeous.
There's some merit in what you say. The loaf on the left was loaded first, centered front to back and on the right side of the stone. The palm slashed loaf was loaded less than one minute later, centered front to back, on the left side of the stone. I rotated the loaves and switched their side-by-side location when I removed the steam pan, but by that time the oven spring had been realized.
I should add, I'm not disappointed with either of the loaves. We've sliced into the palm slashed loaf, and its got the flavor, and chewy crumb we've come to expect and love. But my curiosity is up. I'm going to do two loaves with identical (as near as possible) shaping and slashing first, using the same positioning, temperatures, preheat, and steaming. I also think I can load them at the same instant--never tried loading two boules at the same time before, but I think I've got a safe way to do it. If they display significant volume difference I'm going to suspect I've got an unevenly heated oven when in conventional mode. I hope not, because I discovered the convection fan was drying the doughs' surface. It was especially noticeable in the rearmost baguette (nearest the fan) when I baked them in the convection mode. Since then, I've been baking all my breads with the convection off during the steaming period, and finishing with the convection on after I remove the steam.
Once that's done, I'll do exactly what you recommend, although if the simutaneous loading works, what do you think about eliminating the loading time difference?
David G.
I think all of the variables mentioned are playing a role. So, if your goal is uniformity, you want to eliminate every source of variation, as much as possible.
So, simultaneous loading is good. (I solved this problem for myself by buying an "extension" for my Super Peel that accommodates two large boules or 4 baguettes.)
Your description of how you place your loaves suggests something else I must definitely try: I tend to place one boule in the left rear corner and the other in the right front corner of my stone. My steaming skillet is at the right front corner. Well, that's not so smart!
I'm going to change how I place my loaves and see if this makes a difference.
BTW, one of my experiments was to place the steaming skillet all the way under the middle of the stone. This resulted in dramatically decreased browning of the bottoms of the loaves and decreased oven spring. That's why I'm convinced that steam coming into direct contact with the stone cools it, at least locally.
I just need one more good reason to buy an infrared thermometer. ;-)
David
I'll come back, in a moment, to the thread's subject, but first. Do you think there is a correlation between the surface temperature of a loaf, and the its internal temperature? If there is, and it can be established one could indirectly measure it--with an infrared themometer! Bet I got you thinking about all those variables;-)
I'm amazed at the responses to what I posted mostly as just an interesting observation, and a sudden concern my oven's temperature is seriously non-homogeneous in conventional mode. Your comments re stone cooling due to steam condensing, and the first loaf's loading as well give me hope any spatial temperature variations aren't the only culprit.
As I replied to hutchandI's illustrations above, it's obvious that slashing influnces the direction oven-spring expansion is encouraged or discouraged, but I've never seen a detailed explanation specifically devoted to those influences--until hutchandI's posting-- and how they manifest in our favorite slashings, or some insight on how we can more intelligently guess those influences. Frankly, my first thought when slashing is its eye-appeal. I give some passing thought to what it might do to the loaf's expansion, but primarily I want the loaf to look good. After my concerns for flavor and mouthfeel, appearance is next in line.
I hope someone takes on slashing--both it's asthetics and structural influences as a thread/project. It's beyond my ken. I'm frequently amazed by what happens to my loaves when I get too creative (or too tentative) with my lame'.
David G
P.S. As to steaming. I've tried placing my wet towel-lined sheet pan above my loaves, but I was disappointed in the results, and I sindged--I wish this text editor had a spellcheck-- my hand on the oven's top edge removing it. I routinely check the browning on my loaves. I get very even browning all around: top, bottom and sides. So I'm staying with my current approach for steaming.
Hi, David.
Baking bread is exposed to 3 kinds of heat: Direct conduction from the baking stone, convection from the hot air surrounding it and radiant heat from the heating element (assuming this isn't blocked by a pan on a shelf above the loaf. I am sure there is a relationship between the loaf's surface temperature and its internal temperature, but it's not a simple one.
Have you read the TFL Scoring Tutorial in the Handbook? That summarizes this topic with information gleaned from Hamelman's and Suas' books. It doesn't address more complex scoring patterns, but, if you understand the basic principles, I think you can extrapolate.
David
I'll take a new look.
David G
Aloha David G,
I don't mind getting old so much, it's just all the rest of the stuff that comes with it. Of course the second picture shows a much larger loaf on the left...sigh. I suppose it's part of the C.R.S. syndrome that's creeping up on me (Can't remember/recognize S...)
So much of this scoring business reminds me in an inverse way of the bracing on the tops of the ukuleles and guitars that I used to make for a living. The various stresses and strains on the top brought about by the torquing force of the bridge resulting in turn by the string tension...but dust and chemical allergies brought an end to that. Hence bread baking! Much nicer dust and bouquet...(^-^) And the whole idea of controlling rise morphology by scoring patterns. What fun! This is a great group.
O, BTW please feel free to visit the "home state" any time. TFL-ers always welcome.
Dave Hurd, Hilo, Hawaii
Many years ago I built a guitar from a Martin kit. When I was glueing the braces to the top, I kept wondering how they figured out (or if they did) the effect of the bracing on the sound, since the top is, afterall, the sound board. My education and work speciality was acoustics, but analyzing those braces effects were beyond me. Just like bread baking, making ukes, and the like, is a lot of art, feel, and craft and little science too.
David G