The Fresh Loaf

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What is the affect of a starter on the gluten and dough strength?

DanAyo's picture
DanAyo

What is the affect of a starter on the gluten and dough strength?

What is the affect of a starter on the gluten and dough strength?

I have read that sourdough starter has a strengthening affect on gluten and dough strength. But my experience seems to indicate the opposite. It’s been quite a while since I baked with yeast, but I don’t remember my loaves shaping out as weak as I experience using a starter.

Dan

gillpugh's picture
gillpugh

I find I don't get much strength in my dough when my starter is past it's peak.  Yesterday's levan was 67 hydration but i think the gluten had already began to break down and it was looking a bit soupy when I added it to my dough.  The result was weak structure and pancake when I put it into the lodge for baking.  I've only been baking for a year or so, so I would also be grateful if a more experienced baker could comment. 

DanAyo's picture
DanAyo

Gill, have you seen this link? http://www.thefreshloaf.com/node/56432/tip-weak-doughs-don%E2%80%99t-have-bake-pancakes

When things don’t go our way, this may be a feasible option.

Dan

gillpugh's picture
gillpugh

Really I should also try just reshaping a bit and put it in a tin, but I’m too obsessed with the perfect boule shape cooked in my lodge, I’m a one trick pony.

 When I put it in the fridge for it’s ferment it looked so tight, and ever optimistic I thought it would be great. I’m always in such a tizz when turning out and slashing, last thing on my mind is changing the way I do things. 

The collar looks great -  is it put on before ferment or  when taking out of baskets ?

DanAyo's picture
DanAyo

The collar is applied after the dough is turned out of the basket. I se parchment paper to make things easier.

Dan

dabrownman's picture
dabrownman

gluten strands and one that is required in moderation, but not too much, because it can destroy the entire gluten structure.

Salt and acid strengthen the gluten structure so both are nice to have in SD bread.  Flour has 30 different proteins but only 2 of them make gluten and it also has a like number of enzymes which are also simple proteins.  Many of them strengthen gluten as well and protease helps to break the protein binds in gluten so that the dough is mire elastic and those large holes we love so much can form when slammer holes next to each other break.  To much protease can ruin the gluten structure.

Here is a nice enzymes in flour primer

http://www.biokemi.org/biozoom/issues/516/articles/2309

DanAyo's picture
DanAyo

Dab, I read often that acid strengthens the  gluten. But why does my dough seem to degrade quicker with a very acidic starter and not as fast with heavily yeasted starter?

Dan

albacore's picture
albacore

I think it's all down to your starter and it's condition. I used to run a 100% starter and in my innocence I used to store it in the fridge and refresh it once a week overnight at 19C. I'd then make a leaven with it in the morning at about 28C for 5 hours and make the dough. The starter was nice and bubbly and looked good to go. It did taste a bit acidic, but I thought that this was the norm.

When I made the bread I was often disappointed - poor gluten development, poor rise and dry crumb. Not every time, but often.

Then I read MCs blog Farine, about Gerard Rubaud and his bakery and became rather captivated by it. I tried making his bread, but the results were disappointing, suffering from the faults mentioned above.

I decided it must be a starter issue; time for a new starter, so I followed Gerard's method quite closely, but with smaller quantities. It creates a starter in about 3 days and since then my loaves have been so much better. There is little acidity (I see excess acidity as the enemy of good gluten development) and gluten development is far superior to what it used to be.

Incidentally my old starter probably started off fine, but probably became imbalanced over time with too low a refreshment temperature. The trouble is, we all have a tendency to keep using it.... I do note that Gerard repropagated his starter from scratch every month or so and I think that this is a very good idea. We shouldn't get too precious about such and such a starter being x years old. I'm not saying you need to remake as often as Gerard did, but it should be the first option to consider if you are having starter issues.

I still keep my starter in the fridge, but it is a stiff starter at 56% and I refresh it at 27C - and so far so good.

Lance

 

DanAyo's picture
DanAyo

Thanks Lance. I read that acid makes gluten strong. But, like you that has not been my experience. It seems there is much dissention among bakers dealing with many subjects. One claims this and the other says that. Thank God for Debra Wink. I read her information similar to the way I read the red text in the Bible <almost>  ;-)

I have a thought that may be of interest to you. Have you considered making a new starter that is fresh with little acid load and right away dehydrating some to be rehydrated at a later date? This way you could have a virgin starter without having to remake one from scratch.

The first thing I do with any new starter is to dehydrate and save as a backup.

Dan

albacore's picture
albacore

Dehydration sounds like a good idea Dan; I might do that. BTW I recommend a stiff starter. It's a little more work but I think it gives better results with less acidity and danger of dough degradation. I also follow Gerard's method of adding a small amount of salt to refreshments and builds.

Lance

DanAyo's picture
DanAyo

Stiff starters,; that’s a great example. One article says stiff starters develop the most acid. Another, wet starters develop maximum acid. I believe wet starters present a much more favorable environment for acids.

I am reminded of an experiment I did some months back. Since I am a big fan of “sour”, I wanted to ferment my doughs for extended lengths of time @ warm temps. Of course, this is a perfect recipe for degraded dough. I wanted to know if the starter and/or the hydration was responsible for the degredation. So I mixed flour and water (autolyse) and observed it over the course of 3 days. At the same time I mixed flour, water, 2% salt, and starter (it was acidic) The one with the starter degraded as it always did. But the flour and water held its strength over a period of 3 days reasonably well.

I have not done this yet, but it might be very informative. Mix 2 separate doughs. One with a very acid starter and other with a “sweet” starter. If we are right the acid starter should degrade the dough more and probably more quickly.

Dan

there is no end to this bread stuff”   ...and I love it.

dabrownman's picture
dabrownman

and dry cold temps promote acetic - so both were always right.  No matter what whole grain in starters levains and dough promote acid production wet dry hot or cold.  Those are the rules to make sour bread by:-)

albacore's picture
albacore

The acidic one will degrade the dough. Think about it: commercial yeast doesn't come with acid and it doesn't degrade the dough.

Incidentally, I am not a great fan of long autolyse. Short time OK, but longer - what's the point? And you are just risking more enzymatic dough damage.

Even short time I think it's best to get the leaven in prior ("fermentolyse")

Lance

DanAyo's picture
DanAyo

I am an avid fan of extended fermentation. I’m talking 18 -19 hours total fermentation @ 77F. Often I don’t bother with an autolyse. I start with a completely incorporated dough. We’re probably on opposite ends of the spectrum. I like extremely sour sourdough. 

Commercial yeast, great thought, no LAB. I could build a poolish, use a small percentage to build a dough and commence the BF. Then proceed as I normally do for 18 hours and check the dough for the degree of degredation.

So many test. So little time.

Dan

Question; I never heard the term fermentolyse, so I googled it. I found where Able (TFL user) used the term. Is it an official term? Does it consist of Levain, water, and flour only, omitting the salt? Or what?

albacore's picture
albacore

It may not be an "official" term (what is?) but you do see it here and there in the breadmaking online literature and on IG. Yes, just omit the salt initially, but fully incorporate levain. Stand 1/2 hour, add salt, incorporate, develop gluten.

Regarding sour, I do like sour notes occasionally, just not all the time. But I want to get fully proficient in making well risen tasty loaves with good crust and crumb structure, but not necessarily sour. Once I am 100% confident in this - and with my new starter and improving manipulative techniques I am not far off - I may turn to trying a few more sour loaves, but I am aware of the danger of dough degradation that this may bring.

Obviously a pro baker is always going to be so much better than I am - look at Abel's loaves; if you're making a 100 loaves a day, you should get very good at at it! I make 2 loaves a week! But there again, I don't have to work in a sweltering hot bakery every day and get up at an ungodly hour!

Lance

gillpugh's picture
gillpugh

I'm very confused now !!  Easily done!  I want my starter to be sweet and not so acidic.  Dry, wet warm or cold??

i still think a acidic starter degrades the flour in the dough, but I'm so confused I may be wrong. Perhaps I just over proved the dough. 

DanAyo's picture
DanAyo

A sweet starter that is fed on the counter likes dry and cool 75F (maybe cooler) or so. Larger feeds can be beneficial. Also make sure to not allow the starter to fall (recede) more than a little.

Mine is “sweet” (favors yeast) and is fed 1:3:5 every 12 hours. I try to keep it at 76F but it is getting warmer here.

Dan

gillpugh's picture
gillpugh

Just doing my levan build and I've done it dry and cool.  It tastes and smells much sweeter than the sour soup I used Monday.  I'll let you know how the bread turned out tomorrow !

DanAyo's picture
DanAyo

Gill, don’t let it recede too much, if at all. If it does starter to cave in before  youare ready, feed it a little more. Just a small amount to hold it over.

Dan

gillpugh's picture
gillpugh

Well I had to go out so put it in the fridge.  Don't normally do that, and will panic and let it go over the edge,

I might be getting in control of my starter!!  Yey!!

came back from my meeting and the starter was perfect. Results are in the dough, let you know tomorrow. 

albacore's picture
albacore

My current regime (inspired by Gerard Rubaud) is:

  • stiff starter @56% hydration, 30% Rubaud wholegrain blend, Mockmilled)
  • stored in fridge, refreshed weekly
  • 1st levain build 5pm 27C
  • 2nd levain build 11pm 24C
  • 3rd levain build (small top up Abel style) 8.30am 27C
  • make dough 11am

Low acid, good activity

Lance

Doc.Dough's picture
Doc.Dough

The issue here seems to be the maturity of the levain.  Some are not allowed to ferment long enough and others are fermented too long.

There is an easy way to determine when it is just right:

When you mix your levain, calculate 2% of the weight of the added flour and weigh the levain (bowl, levain, plastic cover). When the levain has lost the 2% of flour weight, it is ready to use.  This weight loss is a result of CO2 escaping from the levain.  If you continue to let it ferment, it can lose as much as 5% of the weight of the added flour but the rate of weight loss will decline somewhat with time (the population of LAB stops growing when the pH drops below ~3.8; after that the LAB and yeast produce acid and CO2 and the LAB may throw off some glucose which the yeast can use).  You can refrigerate a bit of the levain when it is ripe and at 38°F it will be good for 7 days without feeding.  It will actually live for over four weeks if kept at 38°F, but after that long you will need to do two or three refresh cycles to recover the activity you had in the beginning.

After you do this a few times you will learn what a ripe starter at your chosen hydration looks like when it is ready to use.

DanAyo's picture
DanAyo

I am interested to try this. But, help me understand. “ This weight loss is a result of CO2 escaping from the levain”.

So if 100g flour is fed, there should be a loss of the total gross weight of 2g. I’m thinking CO2 is a gas. How can gas weigh 2 grams? I think of uncompressed gas as nearly weightless. Am I wrong?

Thanks for dumbing this down for me and others lacking the mental horsepower :)

Another question. You wrote about refrigerating a Levain @ 38F for 7 days. Is it ready to be used in a dough without refreshing during that time frame? If so, has it lost any of its lifting ability (yeast) from being refrigerated? Would you consider this refrigerated Levain (after warming on counter) to act much the same as if had been fed on the counter all along?

Lots of questions :( ,   but I really want to understand :) .

I appreciate the elaborate testing and detailed experiments that you share with us.  I believe a lot of things, but I am positive that some, maybe many, are wrong. The problem is, I don’t know which ones they are. You have helped to sort some of them out.  Thanks!

Dan

Doc.Dough's picture
Doc.Dough

Gas has mass, just like anything else so 22.4 liters (at standard temperature and pressure) make a mole of whatever it is, and that 22.4 liters is one molar mass (molecular weight in grams).  CO2 weighs 44.01 g/mol. The average molar mass of air is 28.97g so CO2 as a gas is more dense than air.  When the yeast (or LAB) produce CO2 from the sugars in the dough, the first thing that happens is the CO2 goes into solution in the liquid.  This continues until the liquid is saturated with CO2.  Since CO2 + H2O makes carbonic acid (H2CO3 - a weak acid) the pH of the liquid drops to around 4.8 as it becomes saturated. As additional CO2 is produced, some of what is dissolved in the liquid escapes from the surface as a gas and if you cover your fermentation container with a tight layer of cling film it will begin to inflate as additional CO2 escapes.  Most cling films will keep water vapor inside but will leak other gasses (it depends on the permeability of the plastic to a particular gas, the tightness of the seal, and the partial pressure difference across the membrane). The control volume (bowl, levain, plastic wrap, and any gas inside) is what is weighed by your scale. Since CO2 is more dense than air, you may see a drop in weight if you open the plastic wrap and allow air to replace CO2.  I often see a 1g drop when I open the plastic if I have a big bowl of levain. Can you calculate how much (volume in ml) CO2 has to be replaced by air to yield a 1g reduction in mass? (hint: 22.4 liters would be 44-29=15g so it will be something around 22400/15 but if your scale weighs in grams, you just have to push it over to the next lower gram so it could be a very small amount and still cause the scale to change).

albacore's picture
albacore

Would your 2% rule depend on levain hydration?

Also I guess  pH measurement could also be used to measure levain readiness; maybe not as convenient as weighing, but perhaps a useful pointer to a starter that is becoming over acidic.

Lance

Doc.Dough's picture
Doc.Dough

I run a 100% hydration levain so I know that it works at that level and higher (I have tried levains up to 266% hydration which is why I started using it to estimate maturity - since bubbles are definitely not a good proxy when it is that wet), however I suspect (but have not run the experiment) that at substantially lower hydrations there will be additional CO2 trapped in the foam, though the mobility of the gas may be high enough for a lot of it to diffuse out.  Try it and let us know.

As for pH, it is not a good proxy for levain maturity.  TTA could be used for that purpose, but it is a hard measurement to make in a home kitchen. Acidity is different from pH and pH does not reflect total acid in the levain.  Consider the fact that the pH can be 4.8 before any CO2 begins to escape, and the LAB have stopped replicating at about pH3.8 but the levain is not ripe until the yeast catches up by consuming a lot of the remaining sugars.  During that time the pH may drop to 3.7 (or 3.6 if you have slow yeast or wait long enough) and you know nothing about what the TTA is because the LAB continue to produce acid even after their population stops growing.  And if you want to go deeper, read about Kpa and what it implies in complex solutions (it has to do with dissociation of weak acids of which carbonic, lactic and acetic acids are examples that occur together in your levain).