The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

will it be sour?

Pablo's picture
Pablo

will it be sour?

I've baked basically the same bread since I started here last August.  I think I've got it down pretty well.  I play with changing things a bit here and there, but basically it's working and we like it.  One of the things that I've had to do is to let go of the need to have a really sour loaf.  I moved to wild yeast after the first month or so and played with feeding 2xs a day and different hydrations and I can't say I could really tell a difference once it was expanded out into a loaf.  There is a nice, mild sour undertone, but I lived in the Bay Area for many years and came to expect sourdough to be San Francisco style sourdough, i.e. SOUR.  I imprinted on that and I like it.  I would like my bread to be much sourer than it is.  I've tried many things over the time that I've been baking it.  Here's the latest idea:

I started with 5 grams of seed culture and 10 grams of water and 10 grams of flour and let that double then another 50 grams of water and 50 grams of flour.  So I had 125 grams of 100% hydration starter that was getting active.  I keep my seed culture in the 'fridge and it likes a couple of builds to wake up and get active.  Now I added 250 grams of flour and enough water to get a 50% hydration.  I've put it out on the deck to ferment overnight at cool evening temperature.  My plan is to elaborate that into a dough in the morning, also at 50% and let it ferment awhile in the garage where it's coolest during the day and then to work in enough water to get to a 68% or so hydration and perhaps a bit more fermenting, then proof and bake.

I'm hoping for sour from the dry, cool fermentations.  Wish me luck.  I'll post the results.

:-Paul

xaipete's picture
xaipete

Have you tried proofing it overnight in the refrigerator? That method of proofing gives me the most sour bread and there is a logical reason for it since it forces the bread to again pass through the temperature zone that most favors LAB activity.

http://www.thefreshloaf.com/node/1040

--Pamela

Pablo's picture
Pablo

Yes, I've tried proofing in the 'fridge but still I haven't gotten anything like what I'd like to in the form of sourness.  Generally speaking I'm not very open to subtleness. I want it to hit me over the head.  I was reading about the bacteria that give the sourness liking dry and cool fermenting conditions, so that's why I've tried to maximize that environment.  Oddly, although my 50% build went fine yesterday evening and was nicely bulked up this morning, it was quite difficult to work it back to 50% hydration after adding the water.  In fact, I stopped with 100 grams of flour remainaing.  It seemed to just refuse to take anymore.  Maybe I chickened out, maybe I mismeasured (it's been known to happen) or maybe something else.  Anyway, there's a very stiff and lovely ball of dough downstairs in the coolest spot that I could find fermenting away.  I hope someday to get a new 'fridge and when we do, I've got dibs on the old one to turn into a 50F proofing/flour storage box.  That's assuming that a 'fridge will go that high.  Anyway, thanks for the suggestion.

:-Paul

xaipete's picture
xaipete

People have bought those inexpensive portable fridges for such purposes.

--Pamela

Pablo's picture
Pablo

Well, so much for that.  If anything it was less sour than my regular bread.  This stuff remains mysterious to me.  Back to the drawing board.  I do have another 1000 grams in the 'fridge that I'll bake tomorrow.  I don't see that shaping it into loaves to proof overnight in the 'fridge would be any different than simply leaving it in the 'fridge overnight as an unshaped mass and then shaping and baking tomorrow.  I mean I don't see how that would change the flavour-acid component.  Anyway, this was quite a bit more work than my regular bread baking routine and very disappointing in the flavour of the result.  Sigh.

:-Paul

Pablo's picture
Pablo

loaf comparison

The loaf on the left was the first bake, the loaf on the right was 24 hours later.  I think that they were both slightly over-proofed.  The crumb is not very open on either, but on the left it's more condensed near the crust than on the right.  Besides the extra 24 hours, I was gentler with the loaf shaping with the one on the right.  I think that that was what made the difference.   I've gradually been getting gentler with the dough after the final ferment.  I followed Dan DiMuzio's advice when rolling the baguettes: just one push and pull per section.  I had been rolling them relatively aggressively before.  This time I didn't worry too much about getting the perfect baguette shape so much as only rolling each section one time to minimize collapsing the dough.  That was pretty cool.  I'll keep working on that.

After a day there is much more sour flavour noticable.  Still, too much work and too weird to be a regular baking method for these results.

:-Paul

 

davidg618's picture
davidg618

...on the subject of of sour.  Here's what I think I've gleaned from, frankly, some rather esoteric sources on the internet. Not surprisingly, there is a lot published in scientific journals on the subject of sourdough starters--especially from California universities. However, I had to learn enough of the biologist's vocabulary to understand at least the essence of the studies, but not all the details.

Here is my simplified model of what I think is useful (or at least interesting) to us amateur bakers.

Mature sourdough starters contain yeast, and bacteria. Yeast can eat food--in bread dough, sugars converted from grain starches in hydrated flours--in two ways, aerobically (oxygen present) or anaerobically (oxygen absent). Anaerobically, the main results are a lot more active yeast (high reproduction rate), and carbon dioxide; anaerobically, a lower rate of reproduction, carbon dioxide, and alchohol. Bacteria eat some of the same sugars, anaerobically only, and release carbon dioxide and acids. Bacteria reproduce more slowly than yeast. The primary acids bacteria release are lactic acid and acetic acid. These acids are the main source of the sour in sourdough.Yeast primarily contributes the bulk of the carbon dioxide that makes bread dough rise.

A digression: A microbiologist, reading this, would be groaning over my omissions and inaccuracies, but I think it will still help us understand what we amateurs can do to influence our starters.

A starter's temperature is one of the major influences we can control, and a starter's temperature has significant influence over carbon dioxide production and acid production, i.e., gas and sourness.

Yeast first: Yeast performs better (more  carbon dioxide) at warmer temperatures, but not too warm, or our time "window of opportunity to control" gets smaller. From what I gleaned, the magic dough target temperature of 77°F was mostly derived from experience as a convenient temperature for commercial baking operations. It provides a working dough manipulation and proofing interval that supports multiple bakings throughout a day's work. (If I've misinterpreted this primary purpose of target temperature, I'd be happy to be corrected.) Yeast produces well over a wide range of temperatures, but we can only keep a room, or a proof box, at one temperature at any moment. The key here, from my point of view, for both the amateur and the professional baker that single temperature is a "convenient" temperature that supports the entire process, ingredients to finished bread, and is also comfortable for the men and women carrying out the process. I don't want to beat a dead horse, but it's an important one. If yeast needed, let's say 80°F to 95°F, to riise optimally for our chosen process, we would have isolated areas set aside for that purpose, and the humans wouldn't spend a lot of their time in them. We, in fact, do just that. We ameteurs use the oven, light on, door closed; but we don't crawl in with the dough. I understand that some commercial bakeries speed up proofing placing the shaped or panned dough in warm enclolsures.

Bacteria produces primarily (or only) lactic acid at the warmer temperatures preferred for yeast development. Lactic acid contributes only mild sourness. At lower temoeratures, e.g.,  as low as 50°F, bacteria produces lactic and acetic acids; it is the latter that provides the distinctive sourness many of us like (D. DiMuzio calls this an American affectation, other countries, e.g. France, prefer a milder sourness, and some, e.g., Spain and Italy, for the most part avoid it.)

So what?

Well, a couple of things: When we retard dough in the refrigerator, for about 24 hours, most of us report a more distinctive sour flavor than the same dough bulk fermented at room temperature for only a couple of hours. During retardation, the dough passes through a range of temperatures that favor acetic acid production. However, home refrigerators ultimately reach a temperature, ~40°F, that is sub-obtimum for acid production. Nonetheless, we gain a degree of contol (pun intended) over our bread's flavor by retarding bulk fermentation in our refrigerator: the bactera has more time to do its work, in a favorable temperature environment.

An aside: Oven spring is an analogous result. While bread dough is passing through its journey from proofing temeperature (~77°F) to finished bread temperature (~205°F) it passes through a range of temperatures wherein carbon dioxide production increases exponentially; i.e., the yeast is burping like mad!

I'm doing an experiment as I write this. Earlier today I started building a fresh starter to bake, once again, D. DiMuzio's SF-like SD. The first two builds were held at room temperature. (~74°F). Conveniently, I have a wine closet--it's too small to call a wine cellar--it's maintained at 55°F. Immediately after adding the flour and water for Build 3, I put the developing starter in the wine closet (next to a recently bottled Sauvignon Blanc); I'm going to leave it there for twelve hours, then leave it at room temperature for 3-4 hours.to reawake the yeast, just like we do when retarding the finished dough. The starter contributes 480g to the final 1700g dough weight. My hypothesis is retarding the starter only, will contribute more sourness. The microbiolgists' controlled experiments yielded more acetic acid production at these temperatures; hopefully, my starter is similarly capable. I'll post the results in a couple of days.

I just proof-read this, and edited it--four times to fix typos. Boy, I get wordy. Is that a literary form of over-proofing?

David G

Pablo's picture
Pablo

My magic moment will be when we replace the kitchen 'fridge and it can become the fermentarium.  I'm hoping a 'fridge will get up to 55.  That seems the perfect temperature to have access to.  I'll be very interested in the outcome of your experiments.

The tretis was great to read.  Comprehension faded in and out at times, but I'm reasonably sure that's me and on a reread I'll be clearer.  The boil it down, we want multiple long cold fermentations at dryer consistencies. 

If you wouldn't mind, can you describe what you did in those "two builds"? 

  *To me, two builds means I started with my 5gm seed culture and  added 10g water and 10g flour and that's build 1, total 25g. Let ferment to at least double.

  *I then fermented that 25g of build1 with 50 grams of water and 50 grams of flour and that's build 2, total 125g.  Let ferment to at least double. 

Build 3 was the 50% hydration - I fermented build 2 with 125 grams of water and 250 grams of flour, total 500g.  Let ferment to at least double.  In a cool environment - floating in the bathtub in cool water.

mixed by dough based on 500g build 3, plus 1000g flour plus enough water to get to a 68% hydration and salt.  Ferment to at least double.

All of that fermentation might benefit from the 55 degree optimal fermentation temperature.  I tried floating the sealed plastic dough containers in cool water in the bath tub.  None of my thermometers seem to cover that range of the scale so I haad to estimate.  But I left it floating in there for 6 hours and it really rose hard. 

That's why I'm so interested in your current experiment.

I hope that you post detailed procedures and results.  I had a revelationn about being gentler with my dough with this experiment.

I wasn't sure about this, by the way:

"Anaerobically, the main results are a lot more active yeast (high reproduction rate), and carbon dioxide; anaerobically, a lower rate of reproduction, carbon dioxide, and alchohol. Bacteria eat some of the same sugars, anaerobically only, and release carbon dioxide and acids. "

Was one of those "anaerobically"s supposed to be "aerobically"?

:-Paul

 

davidg618's picture
davidg618

Paul found an error in my post above, but for an unknown reason I'm no longer allowed to edit it. In the third paragraph, second sentence, the first word should be "Aerobically"

Thank you, Paul

David G.

davidg618's picture
davidg618

Not surprisingly, there is another thread running parallel, "Effects of fermentation and soaking", I just found that has more good info on starter chemistry and biology.

David G

davidg618's picture
davidg618

Paul,

I use a simple approach. I'll use what I just built as my example.

D. DiMuzio's SF-like SD formula (firm levain) calls for 480 g of fresh starter, at 60% hydration. Because I always loose a little fresh starter transfering it from its container to the mixing bowl and the mass changes downwards during the building--I think its water evaporation, and escaped CO2--I started with the goal of making 500g of fresh starter at 60% hydration. Each build adds the amount of flour and water to increase the developing starter's mass by a factor of 3, and decreasing the difference between the target hydration--60%--and the starting hydration of my seed starter--100%--by 1/3 each build.

The math:

I'll explain it, but if you want to use my simple approach I've made a spread sheet that does all the math, and you can download it. All you have to do is enter the target starter mass, hydration, and the seed starter's hydration.

My first build begins with that amount of seed starter that, when tripled 3 times will result in 500 grams of fresh starter, with 60% hydration.

500g divided by 3 x 3 x 3 = 500/27 =18.52g

and, using Baker's Percentage Math the seed starter's flour mass is 9.26g, and its water's mass is also 9.26g

Build 1's flour and water additions:

Difference between 60%, the target starter hydration, and 100%, the seed starter hydration, is -40%. One third of that is 13.3%. so Build 1's intermediate target hydration is 100% - 13.3% = 86.7%

and Build 1's mass is 3 x 18.52 = 55.56

Using Baker's Percentage Math again,for Build 1's intermediate Hydration% (86.7), Build 1's flour weight will be 29.76g and its water mass will be 25.79g. But, these amounts include the seed starter's flour and water masses, so Build 1's flour addition is 29.76g - 9.26g = 20.5g, and its water adddition's mass will be 25.79g - 9.26g = 16.53g.

In identical calculations Build 2's target mass will be Build 1's mass x 3 = 166.67g and its intermediate Hydration% 73.3%, and subtracting Build 1's flour and water mass contributions yields,

Flour addition 66.39g

and water addition 44.72g

Build 3's mass is 3 x 166.67 = 500g, and flour and water additions 216.35g and 116.99g respectively. Final Hydration 60%.

You can see why I built a spreadsheet!

One other comment is appropriate. My scale is only accurate to 1 g, (my original scale's accuracy was in 5 g increments) I round all my additions, and seed starter mass to the nearest gram.

The spreadsheet is available on my wife's website. I don't have one.

http://glitzandglitterboutique.com/davidg618/spreadsheets.html

David G.

davidg618's picture
davidg618

Paul,

If the lower temperature I subjected my fresh starter to during its "Build 3"  9-hour incubation made a difference; i.e., lent more sour flavor, it's too subtle for my pallette. Don't think for a moment, however, I'm disappointed. This bread; everytime i've made it so far its flavors have been excellent: distinct sourness, the whole wheat flour lends its own recognizable flavor, and the crust adds a nutty, charred burst when you bite into it.

I did the experiment to learn a little more about my starter: its make-up (it may not contain significant acetic acid producing bacteria), or my 9 hour low-temp tweak wasn't long enough.

I plan on sticking with my 3-build approach in the future, but simply keeping it at room temperature for all three incubation periods.

Here's a photo of this AM's result.

David G

Pablo's picture
Pablo

Gorgeous bread, David. 

Nomadcruiser53's picture
Nomadcruiser53

That is a fine looking loaf. Too bad my monitor isn't scratch & sniff. Dave