Sourdough experiments

This is the first in what I hope will turn out to be a series of experiments with a basic recipe.
(Apart from anything else I am going to use this to work towards better sourdough baguettes).
With any of these experiments it would be great if some other folk were interested in replicating the experiment in order to make the results more robust. You don't have to follow my recipe exactly, but it is important the the only difference between the two doughs is the variable that we are interested in (in this case starter hydration). [In order to avoid differences in proving, put the second dough in the fridge while baking the first, unless you can bake two at once].

[i]Background[/i]
I posted a recipe for [url=http://sourdough.com/forum/topic/40]Pane Francese[/url] a while ago, with two variations - one using a firm starter (at 64% hydration), and the other using my standard 100% hydration starter.
It seems like the former is fairly common in french sourdough recipes, but I wondered if it made any difference whether you used a firm 'dough'-like starter, or one more like a batter. (I know that Bill usually uses an even more watery version at ~166%). So I have put the two head to head.

[i]Aim[/i]
To determine if differences in starter hydration make any difference to the rising behaviour or end texture of loaves in a simple white sourdough recipe

[i]Method[/i]
I followed the recipe more or less to the letter. I refreshed my standard starter (at 100%) for 12 hours, and then added 30g of this to two different jars. To one I added 50g water and 100g flour, to the other I added 75g each of flour and water.
They were left for 12 hours at room temp (15-20C)
The amount of water in the actual recipe was reduced in the '100%' version so that the overall hydration of the dough would be equivalent. (350g in the 64% recipe, 320g in the '100% recipe')

Proved for four hours with turns every hour. I wondered if the 64% had slightly more activity, with more bubbles evident on slashing the dough, but there was little difference between the two.

The doughs were shaped, and wrapped in a tea towel, and left to prove. [I did something that I haven't previously done, which was to leave them to prove overnight out on the balcony. I hoped that the cool temperature (but warmer than the fridge) would let them prove without me having to get them out of the fridge in the middle of the night. Last night was quite a mild night for Melbourne - 14C at midnight, dropping to 10C by 5am).
Left for 7 hours or so, then put in the fridge while the oven warmed up.

[i]Results[/i]
[img]http://sourdough.com/gallery/d/4006-1/DSCN1037.jpg[/img]

The one on the left was the 64% starter.
Not much to tell between the two. I thought that the 100% loaf had slightly better oven spring, but not much to tell.

[b]64% crumb[/b]

see above for a bit of a guide
(sorry picture too blurry - will need to take another one)

[b]100% crumb[/b]
[img]http://sourdough.com/gallery/d/4010-1/DSCN1043.jpg[/img]

I had to go to work, so left my faithful assistant to document and dissect the loaves. It looks as though the 100% loaf had a slightly better texture, but I think I am going to have to go home and interrogate the loaves a bit more to be sure.

[i]Conclusion[/i]
Not much discernible difference using a firm starter or a more liquid starter. Possibly more open texture with the liquid starter.

I wonder whether differences would be more marked between 64% and 166% starter? Another experiment to do perhaps

cheers
Dom


15 comments

[quote="SourDom"]
Hi Danubian,

it is great to have your input into the forum, and I am glad to see that someone is out there reading these old threads!

The above experiment did hold overall total water proportion (dough hydration) to be the same, while adjusting just the relative amount of water in the starter (starter hydration)

It is a while since I did this experiment, but I have since baked a lot of loaves with either stiff or liquid starters. I have certainly noticed a difference in the acidity of the starter (more liquid starter, more acidic, firmer starter - more subtle flavour). And I think I can notice the difference that you and chembake allude to in terms of what you call "pan flow". Doughs with higher hydration starters - or with higher proportion of 'prefermented' flour are stickier/looser than I would expect for their actual dough hydration.

I haven't done any formal experiments for a while - too busy at work
[/quote]

Dom,

Thanks for saying so, I've only just discovered this board over the last couple of weeks so I'm going over the old threads to see what I can learn.

I'm a little in experienced with wheat sourdoughs and the French methods in general so although I might have read about them in the past I'm keen to learn more about those methods, although better if adapted and expressed in an Australian context.

Hi Danubian,

it is great to have your input into the forum, and I am glad to see that someone is out there reading these old threads!

The above experiment did hold overall total water proportion (dough hydration) to be the same, while adjusting just the relative amount of water in the starter (starter hydration)

It is a while since I did this experiment, but I have since baked a lot of loaves with either stiff or liquid starters. I have certainly noticed a difference in the acidity of the starter (more liquid starter, more acidic, firmer starter - more subtle flavour). And I think I can notice the difference that you and chembake allude to in terms of what you call "pan flow". Doughs with higher hydration starters - or with higher proportion of 'prefermented' flour are stickier/looser than I would expect for their actual dough hydration.

I haven't done any formal experiments for a while - too busy at work

cheers
Dom


[quote="chembake"]
[quote="SourDom"]
I am not sure how the different hydration starters would affect the 'flow' of a loaf if the overall hydration of a dough is the same (ie if the water is reduced in the 100% starter version).
[/quote]

Based from my experience with starters hydrated at 100% and 65% there is the difference in bread symmetry?.even if the resulting dough have the same total hydration. It becomes more obvious as the starter hydration is raised to 120-150% the bread loaves appears to be less rounded than the ones made from firmer starter.
Yes the crumb grain appears more open with fluid starters.
If I had to use really fluid starter I reduce slightly the hydration which results in slight dough firmness and it resulted in more even grain.
[/quote]

Dom, you have used two hydration levels 100 -65%? Did you vary the sourdough content in the respective batches or were they incorporated at the same levels?

IMO, as a general rule, increased hydration in sourdough not only alters some of the microflora makeup, and lactic - acetic acid ratios, but usually results in a slightly lower pH, although not dramatic, and a considerably higher Titratable Acidity (TA) compared with lower hydrated sourdough, provided the other critical parameters remained the same.

Hence, I agree with chem, lower pH and higher TA with sourdough added at the same rate would produce more flattening or pan-flow.

As an experiment to prove the point one could make three loaves with [b]increasing sourdough hydration levels[/b] but adjusting the total water to be the same in each bread dough, and document the volume, symmetry, and crumb structure, etc.

However, since you're unlikely to measure the TA you'd need to do the following to demonstrate this has the same effect as increasing the TA by going further and make three samples with a sourdough at 65% hydration at [b]increasing sourdough levels[/b] but with the same total water in the bread dough as the above, and document the results again. It should yield similar results. The higher the TA - increase in acid volume - the greater the pan-flow and increasing difficulty in dough handling.

This isn't for everyone and of course, you could save yourself the bother and read about it a cereal science text.

Good luck

Dom.
being a scientist I think you should say EUREKA after every succesful experiment

Laughing

Cool

I feel like a mad scientist in his lab. (Apart from anything else I have created three hunchbacks in my lab this week!)

I was inspired by a discussion thread that I had been having with Bill.
This week I have pitted Dan Lepard's brief hand kneads against a 6 minute knead and a 12 minute knead - is there any effect on loaf texture?

[url]http://sourdough.com/blog/sourdom[/url]

[img]/bread/people/sourdom/expt+_4+250606+loaves+1+to+3.JPG[/img]

cheers
Dom


Dom's experiment is great and I'm posting this here instead of as a comment after his blog because I wanted to use the photos.
Higher hydration can produce larger holes, but the recipe itself, and the techniques used can also influence the hole size.

Compare below, my crumb at 64% hyd, and Dom's crumb at 76% hyd.

[img]http://www.sourdough.com.au/gallery/d/3954-1/new_25May+001.jpg[/img]

[img]http://sourdom.sourdough.net.au/files/2006/06/SE%203%20170606%20loaf%204%20close.JPG[/img]

Another experiment this weekend (it has taken a day or two to find time to post the results).

This week - the effect of dough hydration on loaf crumb and texture.
Loaves from 66% (on the left) to 76% (on the right)

[img]/bread/people/sourdom/Sourdough+expt+3+loaves+170606.JPG[/img]

For full details have a look at [url=http://sourdough.com/blog/sourdom]my blog[/url].

cheers
Dom


thanks Chembake

[quote]
BTW the current bread pictures looks nice externally
[/quote]

high praise indeed!

If you want to have a look on the inside have a look at [url=http://sourdough.com/blog/sourdom]the blog[/url].
I have fixed the pictures so that if you click on the thumbnails a larger version will appear.

cheers
Dom


[quote]
I am not sure how the different hydration starters would affect the 'flow' of a loaf if the overall hydration of a dough is the same (ie if the water is reduced in the 100% starter version).
[/quote]

Based from my experience with starters hydrated at 100% and 65% there is the difference in bread symmetry?.even if the resulting dough have the same total hydration. It becomes more obvious as the starter hydration is raised to 120-150% the bread loaves appears to be less rounded than the ones made from firmer starter.
Yes the crumb grain appears more open with fluid starters.
If I had to use really fluid starter I reduce slightly the hydration which results in slight dough firmness and it resulted in more even grain.

BTW the current bread pictures looks nice externally

Cool

[quote]
What is the effect of different flours on the pane francese recipe?
What difference does it make it you add small proportions of plain (low protein) white flour?
[/quote]

In general breadmaking the addition of significant amounts of lower protein flour to strong flour tends to make the crumbgrain finer and also tend to decrease the bread volume and results in a flattish appearing loaves( or less bold looking)..In some cases the slash tends not to open up.

More experiments this weekend.

What is the effect of different flours on the pane francese recipe?
What difference does it make it you add small proportions of plain (low protein) white flour?



I have posted the details on a new blog (Graham will be pleased)
:D
(though at the time of writing it seems to be having a little conniption, so if you can't get to it - try again later when hopefully Maedi will have fixed it)

cheers
Dom

PS - non-identical quadruplets Bill!


Chembake,

I am not sure how the different hydration starters would affect the 'flow' of a loaf if the overall hydration of a dough is the same (ie if the water is reduced in the 100% starter version).
You may be right that differences would be more marked at higher ambient temperatures, so perhaps I will have to repeat this experiment in summer.

cheers
Dom


Hi Dom, if your proofing conditions are cool then the difference between starter hydrations is not that much.
Another factor also is a cold starter which likely results in a cooler dough.
If you have done the fermentation and proofing conditions in warmer ambient and the ratio of the starter to dough flour is t he same , the higher hydration starter tend to exhibit more pan flow and the resulting bread will appear flattish....than the ones with the firmer starter.
In addition to that the crumb structure of 100% stater will be distinctively open.

Hi Dom,

Looks like the 64% percent has a nicer shapr over all, and yet the holiness is more evident in the 1005, hmm, leave it to chenbake, I guess!
Any word on Grahams efforts in a real stove, that solar stuff looked like they were sipping some liquids while baking in the sun!

Ta!
Jeremy

a few closer pictures

[img]http://www.sourdough.com.au/gallery/d/4012-1/DSCN1044.jpg[/img]

64% starter loaf
[img]http://www.sourdough.com.au/gallery/d/4016-1/DSCN1046.jpg[/img]

100% starter loaf
[img]http://www.sourdough.com.au/gallery/d/4014-1/DSCN1045.jpg[/img]

It does seem as though the 100% starter loaf has a more evenly open crumb (its reasonably subtle though).
Both loaves are probably a fraction underproved
I can't taste the difference between the two

cheers
Dom


Dom the mad chemist strikes again!

Laughing

I have noticed a difference in starter hydration myself. I use Northwest Sourdough starter in my plain white loaves because I like the taste of it, and it likes to work at 166% hydration for some unknown reason, I have tried it at 100% and I don't get as good a crumb structure.
However for my rye loaves I use my own starter at 100% and it works great, and for that matter it works great in white loaves too at 100%.

I haven't worried about the science of it, I just give the little dears what they prefer.

Laughing