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Elasticity of sourdough dough - light at the end of the tunnel?

venkitac's picture
venkitac

Elasticity of sourdough dough - light at the end of the tunnel?

I made Hamelman's vermont sourdough with 10% wholewheat again yesterday (I've decided that I'll make this particular bread repeatedly till I get the hang of sourdough, seems to be the best way to learn). This time, I hand-kneaded the dough with the Richard Bertinet technique after a 20 min autolyse. Dough came together surprisingly quickly and developed a lot of strength in like 2-3 mins, it was really elastic but not too extensible - I almost got a full windowpane, but not a full one. I decided that that's sufficient because I'll do folds (plus the dough had some wholewheat after all). I did a fold at 1 hour, dough had developed a lot of extensibility, but elasticity was much lower than an hour ago. After that fold, I did another one at 2 hours, dough again had a lot of extensibility, elasticity was about what it was an hour ago. I did not retard the dough. I proceed to preshpae. After preshape, and rest, when it came to shaping, the dough again had a lot of extensiblity, but it didn't have much elasticity, I couldn't really get a tight skin around it, dough strengh was just not there. In the end, bread had a rather flat profile - tasted good, had good crust, had good volume too, just that it couldn't hold up the shape and height. And for the first time, I baked under a bowl, and I got massive oven spring too!

Net is that at the end of the knead, dough had lots of elasticity, but it didn't really maintain that elasticity despite stretch and folds. I don't think I've seen this with commercial yeast dough, but I could be wrong. Is it the case that for sourdoughs, you need to knead more in the beginning to develop more strength because of the acidic dough? Or is there another trick with sourdough to maintain dough strength? I understand that adding ascorbic acid helps, but I would rather learn to do this right than work around any technical issues I have with additives...

EDIT: In the past, in another thread, I was advised that I need good elasticity and that means mroe stretch and folds. That would mean I'd need the change the recipe to do more folds at more frequent intervals till I get the requisite elasticity (more frequent because I want to avoid changing the time recommended for bulk ferment). After typing all the above, I've been thinking about it more - I think that is probably my solution?

 

xaipete's picture
xaipete

Your finished product doesn't look bad to me, Venkitac. Maybe a little underproofed though. Did you try the finger poking test see when it was ready to bake? Also, did you bake this one under a cloche?

I love the way you faked a cloche. I've done the same many times.

--Pamela

venkitac's picture
venkitac

Thanks!

Yes, poke test - poked, and it bounced back just about half way (note, dough has 15% whole wheat, not 10% as I said originally), then I baked. Under steel bowl, taking a cue from David S. I must say that I have *never* gotten this much oven spring!

Loaf doesn't look bad as such, but I really couldn't get a skin around it, and I had to support it, and really, it was a "propped up loaf" not a "shaped loaf":)

 

hansjoakim's picture
hansjoakim

Hi venkitac,

First, I think your loaf looks pretty good!

I'm trying to get my head around some of the same questions you raised in the original post, and I think these are important for bakers to understand. As I'm still sorting things out myself, I can't guarantee what I'm saying here is correct, but I thought I could put up some thoughts anyway.

I take it you're following Hamelman's formula, and use a liquid levain? Liquid levains are known to promote protease activity, which will increase the extensibility of the dough. Depending on what kind of flours you are using, what kind of loaf you want to make, etc., it may or may not, be a good idea to use a liquid levain. If you'd like to see the effect of levain hydration in practice, you could try Hamelman's ciabatta for instance, first with a poolish (liquid preferment) then with a biga (firm/stiff preferment). I think you would feel the difference between the doughs as you make the folds - the dough made with a poolish would grow increasingly "fluid" and more extensible. More so than the one with a firm preferment at least.

I've also seen scientific experiments on sourdough's influence on the rheology of bread dough. If I remember correctly, it was concluded that the acidity added to bread dough by preferments, increased solubility of proteins. I believe this is linked with increased protease activity, and greater extensibility. More importantly, however, is that the extensiblity increased with fermentation time. So, as time passes (and bulk fermentation gets longer), the dough will get more extensible and softer. This is also what you noticed, I think.  There were also performed experiments where bread dough was chemically acidified. Contrary to the dough with preferment, which got progressively more extensible over time, an immediate reduction in extensibility was observed for the chemically acidified dough.

I'm not sure if I'm the best to offer suggestions for improving your loaf, but I think that a) slightly increasing the initial mixing time, b) add a third fold (e.g. space them by 40 - 45 mins.) and/or c) try a stiff levain next time, could help, at least if you're aiming for a long bulk ferment. You probably need to develop the dough "more aggressively"... in a friendly way ;)

Best of luck! And: I hope you'll share thoughts about any progress/sidesteps/mishaps as you move along!

venkitac's picture
venkitac

Hi Hansjoakim,

I'm using the liquid levain, exactly as suggested by Hamelman (125% hydration), with a starter maintained at 100% hydration. I haven't really played with fermentation time in a scientific way, recording results, yet. Today, I increased initial mixing time just a bit, I'm going to do more frequent folds spaced at 20 mins, and I will definitely update with the results. Thanks for the encouragement!

 

EDIT: BTW, I'm not retarding the loaves at all, it's pretty much ferment for 2 1/2 to 3 hours, proof for 2 hours, and into the oven. I have had bad luck retarding in the past (see the thread Dan pointed to below, where I ended up with a complete mess), so I decided I need to get unretard loaves right before I play with retarding.

venkitac's picture
venkitac

I will take photos of the levain when I mix the levain build and when I use the levain build tomorrow. (Today is already bulk-fermenting). Dan, Hans, thanks for the advice again - but I would rather not change levain hydration just now, because I've baked this particular levain hydration loaf about 7-8 times now. I would rather not go back to square one, I would rather vary other parameters for atleast 3-4 days before I change the formula.

BTW, I wish I had appended the content here:

http://www.thefreshloaf.com/node/13022/sourdoug-succes-almost-last

to this thread. As Hansjoakim said, it would've documented progress in one thread. It's the exact same formula as in this thread, except with 20 S&Fs at 50 and 100 mins, and it did work out better. I will update this thread with today's and tomorrow's bake etc.

venkitac's picture
venkitac

Pictures from today's bake. My camera died on me, so I have pics only of half a loaf (don't ask) and that's why the second pic looks triangular :

 

 

Differences from yesterday:

- Initial mix was a bit longer.

- Instead of 20 S&Fs at 50 and 100 mins, I did an S&F every 15-20 mins for 4 times, then bulk fermented for another 50 mins.

- Yesterday was with my sifted whole wheat flour. The original post, and today's loaf, are all with actual whole wheat flour (10% WW, 90% KA AP).

My observation was that the dough had a LOT more strength today when I increased the initial mix time, and did more frequent S&Fs. The oven spring was the best I have had. As you can see, the scoring marks completely filled out, and the bread held its shape better than yesterday (this was a 1.5 pound loaf, 8 inches diameter, and 3.75 inches tall). All in all, I am happier with the shape of the bread and the massive ovenspring, and the scoring marks are my best effort yet.

But, the crumb seems denser than yesterday (or is that about right for 10% whole wheat?). In addition, there are these large bubbles at the top but the bottom seems rather dense. I think I may have underproofed again, not sure. Also, the crust was thick rather than crunchy - this was under a steel bowl for 10 mins, and 20 mins without the bowl.

I don't have photos of the levain, that will be from tomorrow's bake...

venkitac's picture
venkitac

Ok, here are pictures of starter and levain:

 

Starter when I created levain build:

 

Levain build about 1 hour after mixing levain (125% hydration, per Hamelman):

 

Levain build when I used it this morning, rubber band indicates height at time of mixing yesterday evening. It is about 1.5-1.75 times the height of what it was yesterday:

 

2 more photos of levain build this morning, right before I used it:

 

I didn't really increase the mixing time today, instead I did S&Fs every 15-20 mins, 8 times! I think I underproofed yesterday, so today I really let it proof. Hamelman advocates 2 hours, I kept poking at it till I thought it's in the danger area (but I was wrong still, I think!). Net is that I proofed for 3 hours at room temp, which was scary to me, and then baked. I still got nice oven srping, and the crumb IMO was a lot better:

 

I think it turned out better today. Crumb is certainly more open, but I have a suspicion I overkneaded (or rather, over-S&Fd) the dough (or did I not?). It appears the bread really did need to proof for 3 hours, you can see the square scoring marks in the second photo of the bread, it pretty much filled out (and yeah, there were air bubbles resulting in black spots:(), it seems pretty hard to tell when a sourdough loaf is proofed properly. Bread didn't quite hold its shape despite all the kneading, but it did hold up enough for a decent crumb.

 

Any advice, help, criticism very much appreciated. I've already made the levain for tomorrow - taking what Hans said and Dan's comment earlier in another thread about protease, I'm building the levain at 90% hydration for tomorrow instead of 125.

venkitac's picture
venkitac

I baked a total of 3 loaves in 2 days (vermont sourdough), and here are the results:

 

The first loaf, I baked with 90% hydration levain instead of 125% (but dough hydration remains unchanged - I added extra water to dough to compensate). The dough was significantly stronger and the crumb was softer - but still not soft enough. This was with a 2.5 hour bulk ferment and 2 hour proof, as recommended by Hamelman. I did 8 folds in 2.5 hours, though. The bread really didn't have that much height, crumb was just okay:

 

Second, I baked a loaf with same levain/dough hydation, but I added 0.2% yeast to the dough and kept the bulk ferment times the same (I had to reduce proofing time to 1.15 hours). The dough was significantly stronger than the above when I added the commercial yeast! Which was *very* surprising till I looked in the Fleischmann Instant Yeast bottle, it turns out the yeast has ascorbic acid added to it! The dough was much easier to handle, and you can see the height difference. The crumb was also much airier and lighter, but the "random sourdough holes" in this bread are less. Still, tasted good. Height-wise, this was much better (4 inches tall, 7.5 inches wide):

 

The third loaf, I completely ignored the bulk ferment timings in Hamelman's book. Instead, I S&Fd every 30 mins, and did so 8 times for a total of  4.40 hours of bulk ferment. This loaf had no yeast (nor ascorbic acid!), and I could totally feel the difference in the dough. The dough with ascorbic acid was so much tighter and firmer. In the end, this loaf was much better than the first loaf described in this comment (bulk ferment in 2.5 hours with 8 folds): had more height (3.1 inches), better crumb structure, softer, but didn't have as much height or soft crumb as the yeast-added loaf above:

 

 

Better than the first loaf, somewhat worse than the yeast-added loaf. (But taste was certainly better than yeast-added loaf - even if it was only 0.2% yeast!).

So there are two clear conclusion here:

- protease activity was causing trouble, reducing levain hydration to 90% definitely helped.

- ascorbic acid helps:)

The part which doesn't have as clear-cut conclusions for me:

- Increasing bulk ferment to 4.5 hours rather than the 2.5 hours recommended in the recipe helped. The number of folds where the same in both cases, but the time between the folds was 15 vs. 30 mins, and 30 min loaf was much better. Dough strength was noticeabley better.

- I am not sure whether the commercial yeast helped me gain height. I would like to think that my levain has enough juju and it was just the ascorbic acid that helped.

(As an aside, how come everyone else on TFL is happy with the 2.5 hour bulk ferment recommended in the recipe, and that too at a 125% hydration levain? I'm very curious).

So, for tomorrow, I am not sure what my experiment should be. I am loath to add ascorbic acid and whatnot, but maybe I should give it a shot. Another experiment would be to reduce levain hydration even further. On the whole, if I can get the height of the yeast-addeded loaf above and Hansjoakim's Pain Au Levain crumb, I will be happy as a clam. I suppose it will come after a few hundred loaves and lots of help:)