Sourdough Bread Troubleshooting (Part 1)

[glennbech]

I've beeing using this article as a reference for some time, especially paying attention to the temperature graph showing growth rates of the yeast/lb. sf at different temperatures.

http://www.egullet.com/imgs/egci/sourdough/science.html

It says;

"The right temperature is the single most critical variable. Michael Ganzle and his co-workers did some studies on this. They found the following growth rates of L. sanfranciscensis and C.milleri as function of temperature. Growth rate is ln2/generation time, i.e. a growth rate of 0.7 is a generation (doubling time) of about 1 h. "

Now, after having a rather heavy discussion in the rec.sourdough newsgroup, there I'd like to hear your opinions on my theory.

I claim that finding the right temperature for Yeast growth is meaningless. The following article state that almost no yeast-repoduction is done in anaerobic environments. (A typicall dough is not a very oxygen rich environment.) The research found here state that the maximum yeast increase in a typical dough is 26% (during six hours.) This is a very different scenario from "doubeling" every hour or so (!)

http://home.earthlink.net/~ggda/The_Artisa...#Yeast%20Growth

I'm also starting to question to why low temperatures, and even "room temperature" are good for bulk fermentation.

Why isn't bulk always done at about 32.5c? This is the optimum fermentation temperature for yeast, enzyme activity is hight, and the Lb. Sf grow (they reproduce in environments with no oxygen).

This graph shows the co2 Production of yeast at different temperatures.

Proofing should most definitly be done at around 32.5c? (Maximum co2 production) When proofing, most of the taste development is already done, and we're only interested in rise? I'm havging a hard time believing that bread tastes better if it's been proofing for let's say 4 hours instead of 2. (The Co2 output is significantly higher at 32.5c than 27.5, the difference is probably enough to cut the proofing in half)

Does anyone have some input on this? Doing things Slowly isn't good if it's done only for the sake of doing it slow. There are also a million myths and claims out there whith semi-scientific explanations. This is probably bacuse most bakers are not microbiologists, and that microbiologists probably doesn't bake much :-)

My claim is, in short; Keep temperatures up all the time (32c+) when baking sourdough. There is no reason to go "cold and slow". At least not for bulk/proofing.

Comments?

Edited August 12, 2006 by glennbech (log)

[cognitivefun]

very interesting topic.

My impression is that if you use less yeast, you will end up with longer bulk and proofing times and better quality bread.

Also, retarding in the refrigerator seems to enhance flavor.

Does fermenting at 70F instead of 80F make a difference? My impression is that it does. Bread made quickly seems to have a stronger flavor of yeast and not as developed flavors. But I can't prove that.

Sourdough takes a lot longer to develop than baker's yeast formulas and to my mind produces much, much better flavor. Why, I can't say. Supposedly due to the bacteria as well as the yeast.

When I retard sourdough poolish and then the dough during proofing, the sourdough flavors are marvelous compared to not doing that. So again, slow means better flavor.

[chromedome]

If memory serves, it is the bacterial fermentation (not the yeast fermentation) that develops the characteristic deep and sour flavours of a good sourdough bread. Because the bacteria do not reproduce as quickly as the yeast, the cold-and-slow method allows time for this to take place.

[glennbech]

If memory serves, it is the bacterial fermentation (not the yeast fermentation) that develops the characteristic deep and sour flavours of a good sourdough bread.  Because the bacteria do not reproduce as quickly as the yeast, the cold-and-slow method allows time for this to take place.

←

The bacterial fermentation surely produces the "sour" taste (acids, like lactic acid), but it is not to my knowledge responsible for bringing out other flavours from the flour. If I undersand the chemistry correct, the Enzymes (amylase) that helps to break the complex starch molecyles into simple sugars are responsible for most of those flavours.

Edited August 12, 2006 by glennbech (log)

[glennbech]

very interesting topic.

My impression is that if you use less yeast, you will end up with longer bulk and proofing times and better quality bread.

Also, retarding in the refrigerator seems to enhance flavor.

Does fermenting at 70F instead of 80F make a difference? My impression is that it does. Bread made quickly seems to have a stronger flavor of yeast and not as developed flavors. But I can't prove that.

Sourdough takes a lot longer to develop than baker's yeast formulas and to my mind produces much, much better flavor. Why, I can't say. Supposedly due to the bacteria as well as the yeast.

When I retard sourdough poolish and then the dough during proofing, the sourdough flavors are marvelous compared to not doing that. So again, slow means better flavor.

←

Less yeast means longer bulk. As you already know, The yeast is primarily responsible for making pockets inside of the dough and fill them with Co2. The LB works in symbiosis with the yeast, providing nutrients, and keeping other strains of yeast from becoming dominant (by among other things lowering the Ph of the dough)

If I understand Peter Reinhardt's chapter on bulk fermentation in the BBA correctly, most of the flavours actually come from the process where sugars are derived from the starch in the flour by enzyme activity.

My guess is that this is why we all experience that Slow is good for flavour. More time for these reactions to happen.

However; A rule of thumb in BioChemistry states that for every 10 °C rise in temperature, the enzyme will react twice as fast.

My "theory" is that increasing temperature in all stages of the process, *may* be like pressing "fast forward" on your VCR. You still get to the end of the comerical break, only faster :-)

I'll definitly do some experiments. To bad there isn't a "Myth busters" for home bakers .-)

Edited August 13, 2006 by glennbech (log)

[Bill44]

Increasing temperature may not be a good thing. If you take a look at the Detmold 3 stage process it has specific temps for different activity. The point to consider is that maximum yeast growth occurs at 27C, there is research somewhere to show this for various strains of yeast.

If you want a quick process use commercial yeast, but if you want flavour do it the slow sourdough way.

[glennbech]

Increasing temperature may not be a good thing. If you take a look at the Detmold 3 stage process it has specific temps for different activity. The point to consider is that maximum yeast growth occurs at 27C, there is research somewhere to show this for various strains of yeast. If you want a quick process use commercial yeast, but if you want flavour do it the slow sourdough way.

←

Hi bill44! Samartha's entire site sure is interesting material. As I've understood it, the goal of the Detmold 3 stage process is to provide a consistent way of producing an optimum starter for sourdough baking.

But, after you inncoulate your starter into your dough, do you really need additional

growth of yeast? The research I provided stated found an only 26% increase in yeast cell count in a dough during 6 hours of fermentation. This is mainly because yeast cells only reproduce with access to oxygen. http://home.earthlink.net/~ggda/The_Artisa...Yeast%20Growth)

What I want to experiment with is a high inncoulation of healthy starter (50/50 like samartha's experiments), and increased temperature during bulk to get a high level co2 production and increased enzyme activity to develop flavour.

Enzyme activity doubles with every 10 degrees, so 2 hours at 34c should compare to about 16 hours in the fridge (4c). Please note that my theory is entirely dependant of enzyme activity as the major flavour developer. The yeast also produces much more Co2 at temperatures above 30c, so the dough will probably double faster as well.

My point is that time alone doesn't make the flavour, it's the chemical processes happening to all the raw meterials. I want to see if I can speed up the process, by applying basic microbiology and chemistry knowledge.

Edited August 14, 2006 by glennbech (log)

[cognitivefun]

A worthy goal -- speeding things up while keeping flavor.

What makes it frightfully complex are two factors. One is that all the different processes including the dough's natural enzymatic activity and from the fermentation proceed non-linearly at different rates depending upon temperature.

Then another confounding variable is change in temperature. Starting out warmer, then retarding, then warming up again. The possibilities are endless.

In Pain L'Ancienne, you use very cold water when mixing the dough initially, and then you refrigerate overnight without allowing the dough to warm up. The results are very flavorful, and Reinhart says it is because you give time for enzymes found in the dough to develop the starch into sugars.

The result is very tasty. I just made this last night.

With sourdough of course, there is an idea that bacterial growth continues while the yeast goes dormant so you retard in the refrigerator in order to build sourness.

Very confusing!

[glennbech]

A worthy goal -- speeding things up while keeping flavor.

Flavour will not be comprimised. Im a purist with a taste for science .-)

What makes it frightfully complex are two factors. One is that all the different processes including the dough's natural enzymatic activity and from the fermentation proceed non-linearly at different rates depending upon temperature.

Exactly! This is my main concern at the moment. I was thinking of investing in a water heating pump for an aquarium, and making a stable temperature setup like "samartha" describes in his experiments with home baking with the Detmold 3 stage process. That device may become handy in other situations as well.

Last night I tried to mix the a 100% hydrated dough with the majority of the water and flour and keep it at 40c (I also used warm water) I made a yeasted sponge and let it develop for 2 hours.

With this setup I was hoping to skip bulk fermentation altogether. Most of the flavour will develop in the hot flour/water pancake batter. It saves some time, waiting only for the sponge to activate, and go straight into proofing. The two hours should make up for about 8 hours of taste-developing-bulk-fermentation in room temperature (20c increase in temperature, 4x enzyme activity).

The result? Not very good Im afraid. I "overshot" the temperature, and ended up about at about 50c for my flour/water batter.

I believe that something starts to happen to the gluten or starch ( or both ) at that temperature, I cannot howerver back this up. The crust was "rubbery", almost like I was trying to bake a bagel (And they're boiled! What a coincidence!?)

However, the crust got a very nice colour, and the bread tasted very wheaty and sweet. So I'm not giving up on high-temperature-flavour-development yet.

As soon as I get my apartment back, I'll start to bake some Pain L'Ancienne batches, paralell to my "fast-track sourdough" experiments so I can benchmark my results .-)

Edited August 15, 2006 by glennbech (log)

[michael_g]

I feel a little timid asking you veterans, but I have a pressing question. I'm making my first starter ever -- I've only baked straight doughs before. My starter has been progressing nicely, doubling within a few hours when fed. But I read somewhere in this thread that it shouldn't smell "bad". Now, the starter doesn't smell awful, but it's a pretty sour smell, far more sour than yeasty. Not "spoiled" bad, like spoiled milk or rotting food, but definitely strong and sour. And I wouldn't want to be around it all the time.

If it helps, I've been following the instructions in Joy (what I had handy when I managed to convince my girlfriend to do this). If my terminology is correct, it consists of 50% hydration feedings of a needed 50% hydration dough every 12 hours for 2 days, a 24 hour break (a sanity check -- is it bubbling when left alone?), followed by the same 12 hour 50% hydration schedule.

So: is my sourdough spoiled? Is it a danger to bake with? If the only risk is a bad tasting bread, I'm willing to take that. If there's a risk of botulism toxin...not so much.

Second question. We started the Joy plan on Monday Sunday, so we now have what should be a viable starter. It certainly looks spongy a few hours after feeding, so that's a good sign (I think). What we don't have are baguette pans or shaping baskets. Is oiled saran wrap in a bowl okay, or is that too much? Joy says we can just leave them dome side up and we'll only lose a little height. Any shaping tips for a complete novice?

Edited August 18, 2006 by michael_g (log)

[cajungirl]

I feel a little timid asking you veterans, but I have a pressing question.  I'm making my first starter ever -- I've only baked straight doughs before.  My starter has been progressing nicely,  doubling within a few hours when fed.  But I read somewhere in this thread that it shouldn't smell "bad".  Now, the starter doesn't smell awful, but it's a pretty sour smell, far more sour than yeasty.  Not "spoiled" bad, like spoiled milk or rotting food, but definitely strong and sour.  And I wouldn't want to be around it all the time.

←

Hi Michael and Welcome!

A starter is dangerous is if it starts growing fuzzy or if it gets a pink or green liquid on top. Are you stirring the "hooch" (greyish liquid that forms on top) back in when you feed it? If so, this will increase the sour smell, but won't make it go bad.

Also, you should be fine letting it rise in an oiled bowl. Be sure to let us know how your loaf turns out

Edited August 18, 2006 by cajungirl (log)

[cognitivefun]

my starter started this way but after a week or two it started having a good smell and has been great ever since. So I think you are on the right track.

[michael_g]

Hi Michael and Welcome!

  A starter is dangerous is if it starts growing fuzzy or if it gets a pink or green liquid on top.  Are you stirring the "hooch" (greyish liquid that forms on top) back in when you feed it?  If so, this will increase the sour smell, but won't make it go bad.

Also, you should be fine letting it rise in an oiled bowl.  Be sure to let us know how your loaf turns out 

←

Whew, thanks! There's definitely nothing that gross in my starter. I am indeed stirring in the hooch (without knowing that i was), and the sour smell has indeed been...increasing. Do you de-hooch?

Thanks for the reassurance, cognitivefun. I was getting pretty worried.

The first loaf will be baked tomorrow -- pretty exciting!

[cajungirl]

I de-hooch sometimes and sometimes I don't. The hooch will make your final bread more sour. I live near San Francisco, so sometimes I like a really sour loaf (prevalent around here) but sometimes I use my starter to make other types of bread and don't want it all that sour. Most times I de-hooch though. I'm anxious to hear how your first sourdough experience goes

[David802]

Ok, so after a few THOUSAND hours of reading through everything I can on sourdough, and asking alot of questions to the baker at work,I have come to this thought....How do I Get acid into the starter (because as I understand it thats were the taste comes from right? (If I am wrong please explain why) ) so I Thought...what will give me alot of acid, and after consulting a few people I came to the concusion that asorbic(sp*) would be the way to go...so after a few test runs, I finaly got some sour taste in my dough, with milk! instead of feading my starter (for the second time) with water, I Fed it with 1/2 cup milk, to 1/2 cup bread flour....the starter grew like normal...but in about an hour, the starter stunk so bad I could not put my face more then 6 inches from the bowl it was growing in...(did not smell nasty...just very strong!) after a 6 hour ferment in the fridge (where the dough still had to be punched down twice, while in the fridge, if some one could explain that Id appreciate it) ) and a 2 hour rise, in the oven it goes, for 28 mins, and boom a good tasting sourdough...

I Dont completely understand why this worked but I can tell you (As I munch on good bread) that it worked...whether I get sick or not will be left for another post..but this is what I found...I just thought I would share..and see what the thoughts of the group were..

[jgold550]

I notice that most sourdough formulas specify the use of non-metal bowls. Some experienced bakers I know who have been producing excellent breads for many years say they have used metal bowls without problems. Does anyone know the science or reason behind this proscription of metal bowls? Does it affect flavor or texture?

[cognitivefun]

my rules are I never feed starter anything except water and flour.

To start a new bread loaf, I will take a few tablespoons of my starter and put it in a bowl and add 1 cup of flour and some water to make a stiff batter. I will leave it in the kitchen at room temperature for a day, then refrigerate overnight. The next morning I will take out, warm up a little, and then mix my bread dough with it. I will let the bread dough rise at cool room temperature all day (in the basement) and then shape and refrigerate overnight to begin proofing. The next day I'll remove the loaves, let them proof longer if needed, and bake.

This makes the bread acceptably sour.

If I don't refrigerate the starter overnight, the bread isn't as sour. I just made a batch that way and noticed the difference.

So that to me is the key: let the yeasties do their thing at room temperature, then refrigerate a good long time, which as I understand it puts the yeast into dormancy but lets the bacteria continue multiplying, generating those tasty acids.

[DocDougherty]

I notice that most sourdough formulas specify the use of non-metal bowls.  Some experienced bakers I know who have been producing excellent breads for many years say they have used metal bowls without problems.  Does anyone know the science or reason behind this proscription of metal bowls?  Does it affect flavor or texture?

←

I have read that metal bowls conduct heat "too well" and thus cool off or heat up the dough more (and more rapidly) than one might like. That said, I use only metal bowls (stainless) and have no problems that I can tell.

Doc

[rooftop1000]

I notice that most sourdough formulas specify the use of non-metal bowls.  Some experienced bakers I know who have been producing excellent breads for many years say they have used metal bowls without problems.  Does anyone know the science or reason behind this proscription of metal bowls?  Does it affect flavor or texture?

←

I have read that metal bowls conduct heat "too well" and thus cool off or heat up the dough more (and more rapidly) than one might like. That said, I use only metal bowls (stainless) and have no problems that I can tell.

Doc

←

So there was no reason to panic when I left a spoon in the bowl overnight....good

tracey

[cognitivefun]

My system for making sour sourdough is this:

Day #1 - The poolish. I take out a few tablespoons of my starter, put it in a new small bowl, and add about 1 cup of flour and enough water to make a thick batter. I mix and leave at room temperature for the day. Then I refrigerate overnight. This is my poolish

Day #2 - I mix the poolish with the flour and salt in a food processor using Van Over's method. I do the bulk ferment in the cool basement around 70F. Hours later it has almost doubled in bulk and I then form into loaves. I might proof if there is time. In any event, I refrigerate.

Day #3 - I remove the refrigerated loaves and if needed finish proofing. I heat the oven for 1 hour and then slash, get it in the oven with the steam and bake. I have found there is no need to let the cold loaves warm up.

Over this weekend, I took a shortcut. I didn't refrigerate the starter in Day #1. And I didn't make enough poolish.

As a result, the bread came out perfectly except not as sour as normal.

[Bill44]

I notice that most sourdough formulas specify the use of non-metal bowls.  Some experienced bakers I know who have been producing excellent breads for many years say they have used metal bowls without problems.  Does anyone know the science or reason behind this proscription of metal bowls?  Does it affect flavor or texture?

←

The acid content of sourdough is notorious for attacking metal bowls, in particular stainless steel. You may not notice it just when mixing, but the prolonged storage of any sourdough in a metal bowl should be avoided.

[cajungirl]

Just wanted to pass on a little information. This weekend, for the first time, I used rice flour in my banneton. I made a particularly wet dough specially to try this out.

I have to say I was pleasantly amazed. The dough all but slid out of the banneton onto the peel. I also used some of the flour on the peel. There was not even a hint of sticking to banneton or peel. Yipee!!! Also, at an Asian market, I got a bag for $0.59 What a deal! Then I made another loaf using a couche rubbed with the rice flour, again no sticking. This has solved a really big problem for me... Hope it helps y'all.

[cajungirl]

my rules are I never feed starter anything except water and flour.

To start a new bread loaf, I will take a few tablespoons of my starter and put it in a bowl and add 1 cup of flour and some water to make a stiff batter. I will leave it in the kitchen at room temperature for a day, then refrigerate overnight. The next morning I will take out, warm up a little, and then mix my bread dough with it. I will let the bread dough rise at cool room temperature all day (in the basement) and then shape and refrigerate overnight to begin proofing. The next day I'll remove the loaves, let them proof longer if needed, and bake.

This makes the bread acceptably sour.

If I don't refrigerate the starter overnight, the bread isn't as sour. I just made a batch that way and noticed the difference.

So that to me is the key: let the yeasties do their thing at room temperature, then refrigerate a good long time, which as I understand it puts the yeast into dormancy but lets the bacteria continue multiplying, generating those tasty acids.

←

I agree wholeheartedly! I've never used anything but flour and water to feed my starter. Also, after the yeasties have fed at room temperature, the beasties (bacteria) need the cooler atmosphere to develope the sour taste.

[fiftydollars]

It's all about temperature and the ying and yang of bacteria and yeast that make up typical sourdough starter.

Sourdough starter contains yeast, which doesn't really like heat very much, and bacteria, which needs a certain amount of heat to become active. While at temperatures under75 degrees your yeast will be nice and happy at that temperature you won't get much acidity because the bacteria will not be producing much lactic acid. At temperatures over 90 degrees, your yeast will be somewhat inhibited and possibly start to die off rapidly while the bacteria will be hummin' away happily acidifying the mix. Dough proofed at this temperature (90-93) will be definitely sour, but may not rise all that well.

A good way to strike a balance between the two types of critters is to activate your starter and proof your dough at a temperature between 85-90 degrees. This temperature must be carefully controlled and just a couple degrees can make a big difference. I made a simple proofing box using a cooler and a fish heater submerged in a glass of water (goddamit I'm a clever sonofabitch), but I'm sure you can buy this sort of thing, use your oven, or maybe you can proof your bread in a yoga studio.

You can learn more than anyone needs to know about sourdough bread by reading Dr. Ed Wood's, Classic Sourdoughs. You should also take at look at his website: http://www.sourdo.com. I bought his book and a starter from his site and when I ran into some trouble I emailed him. I was surprised that he answered personally. The doctor (I believe he is an actual medical doctor) diagnosed the problem and I was happily making sourdough in a very short time. (However, it did take me a while to get the acidity just right.)

[cognitivefun]

Funny. I haven't tried warm temperatures but cool ones only. And the bread is coming out consistently very good. I never considered 85F or higher as this doesn't seem to benefit baker's yeast bread, to say the least. The cooler and slower the better, I have been taught. Is this wrong?