High protein flour in leavens

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Thank you guest (Chembake) I take that as a compliment?
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No worries mate,,,, keep up the good work

BTW, I just wonder how did I became a distinguished (guest )i poster nstead of my regular nickname?

Importance of protein in levain raised dough.
The value of high protein (strong) wheat flour in final bread dough is common knowledge amongst bakers. However what qualities does strong flour add to a leaven designed to grow microorganisms?

Generally speaking strong flour enables levain raised dough , stronger. Stable structure, fermentation and proofing tolerance , better bread volume, better crust color, chewy texture better dough symmetry and overall appearance
Higher proteins means there is more of the structural and soluble proteins that have beneficial effect on the critters and the dough .
Questions:

1. How much protein survives intensive fermentation (e.g. 8-16 hours at 20C - 26C, at 100% hydration) in a form that can contribute to the development of gluten in the final dough?
Much protein is intact and not destroyed by microbial metabolism, but they are mellowed due to biochemical degradation bought about the selective protease enzymes found in the microbes which modify the gluten making it extensible but still supple which is partly due to oxidation, reduction mechanism where sulfur hydrogen bonds are converted to disulfide bonds in some areas making it extensible as well as elastic. If those reactions are absent the dough quality will be inferior. Too much elasticity but very minimal extensibility .
The question is applicable to the sponge and dough methods where stronger flour is the preferred base. If you use medium flour for the sponge made for long fermentation and stronger flour for the dough side you will notice that the dough exhibits some peculiarity in characteristics?the dough tends to flow during proofing?.resulting that the dough symmetry is flattish looking and the bread texture is rough and the crumb appearance uneven with grayish streaky appearance.
This confirms that whenever you want to make a preferment such as a biga and you ferment it for long periods of time, its best to use stronger flour and use the medium flour in the dough side.
It?s virtually the same with traditionally fermented dough which confirms the unity of mechanism on the different dough making systems (in many cases).
That is one reason that I kept insisting that breadmaking is the same as the biochemical activities are related if not identical.

If we have to transpose that behavior to sourdough what I found is that that its best to make a starter with stronger flour and preferably use a stronger flour also in the dough side for best results. The degree of gluten softening is greater with acidic environment at pH between 4 and 5 so its recommended to use stronger flour in sourdough preparation specially with high acid san Francisco sourdough system.

2. Most bakers have heard that the leaven (or pre-ferment) benefits the final dough, conditioning (by acidification) unfermented flours, helping to improve dough development and dough texture. How does this process work?

The acidification will modify the non gluten gummy matter in the flour called pentosans which will swell in the acidic environment enabling it stabilize the gluten and enhancing its gas retention properties. That is why that with higher ash flours such as in clears and mix grists, even if the protein content is not very high the dough still is stable than withif compared lower ash patent flours. This makes sense how in Europe where weaker flours predominate but have higher mineral content which reflects in more of the wheat aleurone layers where these hemicellulosic matter( pentosans) originated and contribute the improving effect on levain made doughsl the resulting bread is still good but not as high in volume as similar formulations made in North America with very strong flour.

3. Is the protein in flour a primary nutrient for microorganisms and if so should lower protein flours (of the same grain variety) receive less fermentation than flours of higher protein?

Flour proteins is not just the structural proteins to what we generally call as gluten but also include soluble proteinaceous materials that is still part of the wheat kernel protein that has also and important functional effect
This different protein are degraded easily by microbiological enzymes in yeast and levain contributing to soluble nitrogenous substances, such as amino acids and peptones which are good nutrients for microbial growth, Meanwhile gluten which is stronger is more resistant to degradation but its quaternary structures is slightly modified contributing to the mellowing effect which promotes a balanced ratio of extensibility and elasticity permitting the protein to stabilize gas bubbles without rupturing the gas cell walls.
Regarding the ratio of fermentation time to protein content, that is essentially true with bakers yeast raised dough which shows direct proportions but not with levain raised items. This is partly due to the fact that what mattes is not only the amount of gluten counts as well as the quantity /quality of the pentosans . There is a slight difference in the fermentative mechanism of the sourdough if compared with the bakers yeast dough.
Another thing also with yeast raised dough the pentosan performance is not maximized as the higher pH does not enable it to swell to the fullest extent which confer another improving effect in the dough.

4. If protein is a valuable food source in leavens, then are leavens made with higher protein flour capable of supporting a relatively higher amount of microorganisms?

Protein is not only the food source for leavens as the critters also need sugars at the same time, the flour has an abundant supply of derived sugars from the enzymatic degradation of damaged starches to dextrins and then to maltose and finally to glucose.
BTW
There is no proportionate ratios between protein and microbes

5. Any other points?
It?s a case to case basis?.or a need to know basis?
That depends on what particular issue you and other want to know?

Applause, just good information and less inflammation! Nice, and I have been doing this with my sourdough, using a strong bread flour for the leaven and sometimes mixing a all-purpose flour with a strong flour for the final dough!
In tha gallery you could see some of my final product and make your own conclusions.

Jeremy

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Was our logic flawed? Should we have used hard flour in the leaven and added the soft flour in the final mix instead?
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That is not the way; it should be in reverse.

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If you are adding a percentage of soft wheat flour to wheat bread, will a stronger dough result from adding soft at leaven stage, or using hard wheat in the leaven and adding soft in the final mix?
[/quote] If the stronger flour is added at the leaven stage and the soft flour in the dough stage the resulting dough will be more stable. But the total calculated flour protein should be not lower than 11%. One thing that is a cause of concern is the nature of the Australian flour.
Past experience with it have convinced me that adding weaker flours is not the desirable option but instead reinforcing the weakness by the addition of vital wheat gluten regardless if you are using whole grain or white flours.
Its not impossible to do such treatment by diluting the protein content but expect that the resulting bread will have higher weight to bulk ratio( heavier bread) and you have to exercise care that you don?t over proof it!

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. When adding (say 20%) rye flour to wheat breads will a stronger dough result from adding rye at leaven stage, or using hard wheat in the leaven and add rye in the final mix
[/quote] Rye flour has poor gluten quality and relies mainly in the rye flour pentosans for its gas retention quality.
If you combine the rye and wheat protein, its likely the latter that is responsible for dough strength.
Therefore the less rye you add the stronger and more stable is the dough
I would prefer to blend two levain, the rye and the wheat levain instead for robust flavor and use wheat based flour in the dough side.
Be sure that the rye levain is very minimal just a quarter of the total levain content for the flavor that it contributes only.
If you want to add rye flour in the levain at 20 % I prefer to add half of it in the levain and half in the dough side

Hi Graham,
I actually did a miche recipe where the inocullant was wheat (bread flour or strong flour) the rest of the leaven was whole meal and rye and the final dough had a touch of rye and the rest strong flour! The result a nutty sour dough with lots of airy holes and lots of oven spring and good shelf life! Recently I have been intrested in trying Desem starter, whole meal as the leaven, and I find the bread is really different say to just white flour, not to scientific but I think youve seen the results from my pics!

Jeremy

Thank you guest (Chembake) I take that as a compliment?

Jeremy