The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

Bouabsa w/Poolish

DanAyo's picture
DanAyo

Bouabsa w/Poolish

I wanted to try including a Poolish in a Bouabsa bread. The night before a Poolish was made using a pinch of CY in a 100% hydrated pre-ferment. It tripled overnight and looked perfect for mixing the next morning.

The gluten was developed in a mixer and was folded 3 times at 30-45 min intervals. Dough was smooth and supple. It was shaped and placed into a pullman pan to BF. The dough was mixed and folded over a period of ~3.5 hr at ~69F. It was shaped and panned and placed in the proofer (set to 78F) for 3 hr, then raised temp to 80F and later raised to 84F after a total of 6hr in the proofer the dough has not risen much. Estimate 2.25-2.5X. I expected it to rise an inch or so below the rim, but it is only slightly less than half capacity.

NOTE - no additional CY was added when the dough was mixed. Was under the impression that the Poolish would bring enough yeast into the Final Dough.

  1. Does anyone have thoughts as to why the dough is not rising to expectations? 
  2. Is it feasible to use only a pinch of CY in the Poolish and none there after, or should additional CY be added during the mix of the Final Dough?

The great majority of my breads us SD only, so experience with CY is lacking.

Thanks,
Danny

albacore's picture
albacore

Deffo not enough yeast, Danny. Your pinch, maybe 0.2g, is never going to grow enough to raise the whole batch in good time and without weakened gluten.

I would try adding in 0.3 or 0.4% IDY to the main dough.

 

Lance

DanAyo's picture
DanAyo

The thinking was that the Poolish made with a tiny amount of CY would multiply the yeast exponentially during the overnight ferment. That the matured Poolish would introduce many more yeast cells to the Final Dough as a result of this. Much like a SD Levain would. The Poolish more than tripled overnight.

Am I missing something?

A Large USA Pullman was filled with a TDW of 1200, was expected to fill the cavity to capacity. At the end of BF the dough expanded ~2.75-3x. The bread did rise during the bake, but some tweaking is in order.

Final Question -
Any idea why the bottom and sides browned nicely, but not the top. The top remained on for the full 40min of the bake.

happycat's picture
happycat

Isn't the difference the environment? A starter takes a week+ to become an environment conducive to replication (as opposed to providing lots of food to existing yeast to keep munching and gassing out)?

Doc.Dough's picture
Doc.Dough

I think I can explain the browning or lack thereof. There is clear evidence that the dough touched the lid of the pullman pan and that is why it is browned along the top centerline. The shoulders are light because they did not touch the top to pickup conducted heat and they could not see the hot surface of the oven so could not brown by radiative heating. The sides were in contact with the pan and were browned by conduction.

As for how much yeast a poolish brings to the game, I don't know. A very small amount of yeast should grow exponentially until the sugars are depleted. I have not done the math, but there is a reason that you use a particular amount of CY (% of flour) for a straight dough. If you start with zero you never have any CY and get only the native microfluora contributing.  A little more CY and you get some growth but perhaps not enough to provide the needed CO2 before it diffuses out and the yeast has consumed the available sugars. If you add "enough" then you get a sufficient CO2 production rate to inflate the loaf before the CO2 diffuses out at the surface.  My impression is that poolish was invented as a way to improve the flavor and yeast is added to the main dough followed by BF and proofing.

DanAyo's picture
DanAyo

Is it correct to assume that CY and SD are much the same with the exception of LAB?

Lets consider Sourdough Starter in a levain
We innoculate a levain with a small amount of starter, and the microbes (both yeast and LAB) multiply throughout the fermentation until maturity. Introducing the levain into the Final Dough brings exponentially more microbes to the mix.

Considering Commercial Yeast in a Poolish
With the exception of LAB, doesn’t CY act the same. A tiny bit of yeast initially, but at maturity the yeast cells have greatly multiplied.

  1. Are above thoughts correct?
  2. Also, in your opinion will it be helpful to remake the dough as before but this time eliminating the mixer and using moderate S&F to lightly develop the gluten? The thought here is that highly developed gluten may have constrained the gas pressure, hindering rise.

I recently can to the same conclusion as you concerning the browning. The brown strip in the middle of the top crust seems to confirm that without a doubt. I appreciate your help and the help of others that responded to this post.

Doc.Dough's picture
Doc.Dough

I think it is easier to run the experiment than to debate the theoretical outcome. Just keep good notes on the details.

What I do know is that there is no superalloy gluten that will constrain the CO2 very much since the gas will (and does) diffuse through the dough and escape from the surface with the diffusion rate roughly proportional to the local pressure gradient.

Ming's picture
Ming

I have not used a poolish for a while as nowadays I use a biga with 0.08% instant yeast and that is the only yeast go into the dough. I have lately added 5% levain to the dough as a favor enhancement but my SD starter is very weak so it should not be doing any lifting, I expect the 0.08% instant yeast do all the lifting. However, with this method, my dough usually doubles reliably in about 3 hours but I have never gone pass double so I don't know if it would triple or more, I bet it would. Something does not sound right here as with enough time, the commercial yeast should do its job reliably and would keep expanding until it runs out of gas. 

DanAyo's picture
DanAyo

I checked my spreadsheet and like you 0.08% CY was used in the Poolish. There seems no reason why a biga and a Poolish would not both produce many multiplications of yeast cells.

Doc.Dough's picture
Doc.Dough

I often use 1/8t (~1g) of IDY in addition to 247g of levain that has lost 2% of the added flour weight (and is thus mature by my definition) when I make a batch of sourdough (~1720g of dough after taking 30g for the aliquot jar). This hastens the BF to a typical 1:40 @ 80°F dough temperature.  BF ends at 25% volume increase.  After divide, 30 min rest, and 10 min to shape, the aliquot jar reaches ~80 ml (167% volume expansion) after about 2 - 3 hrs depending on the kitchen temperature, at which point it goes to the oven for 14 minutes.

If you think of the poolish as a levain then you should be able to add 1g of IDY and get a short BF and proof (even if you want to do an extended retard). My mixing varies from 22 min to 28 min depending on the speeds I choose to use for the stages of mixing (combine-4@0, incorporate salt-4@0, develop gluten-6@4, bassinage-6@4, final gluten development-2@4; total 22 min with about 6°F temperature rise as I remember).

Ming's picture
Ming

FYI, I did not pull my 0.08% instant yeast figure out of thin air, it was based on many trial and error bakes to dial in to this amount for my weekly baguette bake(s). I wanted to control the amount of fermentation time and with this % I have been able to finish the bake from mixing to baking within a 5-hour window. From my limited experience, the amount of instant yeast has nothing to do with amount of rise, it has more to do with time, and obviously temperatures have a lot of influence with it. A 0.08% instant yeast is a very small amount of yeast especially for a one-person household loaf, in fact, my high-end digital scale cannot register anything below 0.3 g, so when I have the urge to measure accurately with a small dough, I use my miniature gun powder (I make my own ammo) balance beam scale as that is the only way to measure it accurately.

alfanso's picture
alfanso

As soon as you add a poolish to the final dough it is no longer a Bouabsa dough.  Bouabsa is a straight dough.  The way I perceive the dough was designed was that the entire dough is a preferment, being retarded for ~20 hours after a short bench rest and few BF folds.  

Whatever visible growth there is happens over the course of the BF during that first hour before retarding the dough, and then if one does a bench rest proof for ~45-60 min before baking.  It's just paying it's initiation dues during that BF hour, with the real magic happening during the long retard where it has a chance to mature and develop flavor.

It typically exhibits significant oven spring.  This wasn't meant to be a countertop only dough.

alan

DanAyo's picture
DanAyo

Just had a new thought, and beginning to wonder.
The gluten, through both machine mixing and stretch and folds was well developed. Possibly the gluten was strong enough to hinder dough expansion. The flour was King Arthur All Purpose, so not a super high protein.

The dough was well developed because large holes were not desired.

Not sure that answers the problem, but it is a thought.

alfanso's picture
alfanso

What you might consider is to aggressively degas the dough as you roll it up to load into the pullman.  Just the opposite of what you would look to do for a typical shaping.

Dan give me your total dough weight for a 9x4x4 pullman.  As I mentioned to you yesterday, I don't have a cover, but now you have my curiosity up and I want to do a run.

DanAyo's picture
DanAyo

I only used the Bouabsa as the framework for my dough. There was no intention to replicate the exact formula. You recently replied to ANOTHER POST that better explains the goals of this bread.

The dough was thoroughly degassed before shaping.

Never having baked this dough before a guess of 1200 TDW was estimated. That guess is based on many bakes with the large 13x4x4 USA Pullman.

Using the math above.
13*4*4=208
9*4*4=144
208/144=.692
.692*1200=830g TDW

Only a rough estimate, using limited math skills 830g should be a good starting point for a small USA Pullman bake.
oh! An uncovered pullman will benefit from a little larger dough because it is expected to rise above the top of the pan.

Different doughs will rise to different heights. In my experience some experimentation may be needed to dial in the ideal TDW for a particular dough using a pan of a certain capacity (cubic inches). Example - a seeded whole wheat dough will require more TDW for a given pan than a light and airy white flour dough.

Hope I got the math and explanation correct.

Benito's picture
Benito

In terms of mass of dough, for my 100% WW pullman loaves uncovered I aim for about 900-970 of total dough weigh as I like a tall loaf. However, my toasters isn’t as happy with these tall slices so I’ve been adjusting down to 900 g. When I used only white flour I made a note to reduce the dough weight to somewhere between 700-800 g but I haven’t tested that yet since being on a whole grain path lately.  But 900 g in a 9x4x4” pullman is an extremely tall loaf and the side walls do start to collapse inward as it cool somewhat even with baking the loaf in the oven out of the pan for 10 mins.

alfanso's picture
alfanso

I began my mix 5 minutes after your reply last night.  I didn't give the dough the full ~20 hour retard treatment because I was a little to gung-ho too wait longer, but it got most of the way there.  Following the advice from you and Benny I carved out ~850 grams for the Pullman and used the remaining 180g to make a slender braid just for fun.

I won't cut into it until it cools down, but it doesn't seem like nearly enough dough.  Maybe I rolled it too tight!  If I travel this route again, I'll put the entire mix into the pan with a less aggressive roll.

480df for 23 minutes, then tented for another 15 minutes to reach at least 205dF internally.

 

alfanso's picture
alfanso

It is a very dense dough, again, maybe I shouldn't have rolled it so tight.  The post bake weight is 725g, which means that it shed about 15% of its pre-bake weight.  But the lack of rise makes this a much denser bread than it might otherwise be.

It seems that this is the type of tight crumb Dan may be looking for, but it certainly isn't light - as of yet.

I'm still new to Pullman pans and loaf pan breads, this being only the second Pullman I've made, so I'm in a learning curve phase now.

DanAyo's picture
DanAyo

My crumb looked similar to yours. The slices were not light. The chew was moderately rubbery. Flavor was uneventful. The rise was similar but not quite as high as yours. Not at all what I was looking for. 

Looking at the bottom image of the loaves, I learned something that confirmed Doc’s thoughts. The light golden line on the top of the loaf indicates to me that the sides that touched the pan browned nicely, so did the very top. The sides of the top was probably shielded by the sides of the pan and also not high enough to get full heat. It might brown completely if the loaf was removed from the pan and baked in the oven to allow full browning. Do you agree?

I think that if the dough rose as we’d expect, that the TDW would have easily produced high slices. Maybe even too much dough, but not sure.

Benito's picture
Benito

From that photo, which may not be accurate, I‘d say that the loaf was baked too high in the oven.  The bottom crust of those slices look very pale.  I’ve found that I bake my pullman loaves low in the oven so that the bottom is closer to the heat to induce that oven spring that is needed.  Was the bottom crust as pale as it appears in the oven?  I would have expected a greater rise in the dough than you got given the 850 g of dough weight in a 9x4x4” pullman pan.

Benny

alfanso's picture
alfanso

The same as every other bake, the baking deck sits just above the steaming pan, and therefore on the second lowest rack setting.  I also placed the Pullman on a cookie sheet cooling rack in the oven so that it wouldst about a half inch above the baking deck.  Perhaps the Pullman should be placed directly on the baking deck?  And I never thought of removing the loaf from the pan after the steam cycle, something worth trying.

The lighter shade on the entire bottom of the loaf, basically a blonde color seems somewhat "typical"for a white bread in a loaf pan, maybe not.  Removing the loaf from the pan and placing directly on the baking deck at the "half-way" mark should remedy that.  It also should cut down the entire bake time, which I was surprised was so long - total of 38 minutes, the last 15 tented.

The halo just below the crown may indeed be from the Pullman sides shielding it from some of the heat.  

This is starting pique my curiosity and I have the itch to run another batch today for a tomorrow bake.  I'm sticking by my thought that I deflated the dough too much without a pre-shape period and was robbed from some the loft that it otherwise should have had.  

Just consulted the Hamelman Bread book.  In the two places he mentions a Pullman loaf, (2nd ed., p.288 & 297) he mentions to do a soft pre-shape and let the dough relax.  Which I did not do, going straight from retard to roll-up.  However, in one shaping description he mentions rolling into a "tight cylinder" and in the other just roll into a cylinder.  He also mention in the second case, the dough should come halfway up the pan, which mine did not.

Another consideration is that I pulled the dough from retard and shaped immediately, instead of allowing for the dough to warm up, at least a little, and something that the pre-shape and relax time would help with.

Details, details, details...got some work to do up ahead!

Thanks gents, Alan 

DanAyo's picture
DanAyo

“ I'm sticking by my thought that I deflated the dough too much without a pre-shape period and was robbed from some the loft that it otherwise should have had”

Since I was operating under the assumption that the pre-ferment was introducing loads of yeast (via multiplication), me dough was also thoroughly degassed to avoid large holes. BUT the rise was super disappointing.

albacore's picture
albacore

When making traditional British tin loaves, the dough is degassed as much as possible before shaping to avoid unwanted large holes.

This is done either with a rolling pin or a set of rolls, like a sheeter.

And yet the dough rises very well afterwards. So I don't think degassing should be a barrier to a good rise, even though crumb structure will be different.

Lance

a.peabody's picture
a.peabody

I second this point - strongly deflating the (CY) dough should have no impact on the potential volume increase during second fermentation, only the resulting texture.

Have you considered something high hydration, one time fermentation straight in the tin?

DanAyo's picture
DanAyo

“one time fermentation in pan”. That is exactly what I tried. 

Followed instructions HERE .
An excerpt from that post, “ in an effort to simplify and streamline the sandwich bread I wondered if the dough could be shaped immediately after mixing and then placed in the Pullman to BF and later bake. I supposed that the pan would constrain the dough from spreading so shaping might be done at the beginning of fermentation rather than towards the end after the BF.

I think confusion was created when the topic read “Bouabsa with poolish”. The method Bouabsa method was not used, only the basic Baker’s Percentages.

a.peabody's picture
a.peabody

I've re-read your original procedure from this thread and am slightly confused now.

"The gluten was developed in a mixer and was folded 3 times at 30-45 min intervals. Dough was smooth and supple. It was shaped and placed into a pullman pan to BF. The dough was mixed and folded over a period of ~3.5 hr at ~69F. It was shaped and panned and placed in the proofer (set to 78F) for 3 hr, then raised temp to 80F and later raised to 84F after a total of 6hr in the proofer the dough has not risen much."

I thought this meant the dough was kneaded in a mixer, there was a bulk ferment with folds over 3.5 hours, then the dough was shaped and placed in a pullman pan and proofed for 6 hours.

So that would be twice fermented, right? (Double fermented? What is the standard English term?)

alfanso's picture
alfanso

is 100% "preferment" all AP flour at 75% overall hydration.

I've made note of this conversation, and will apply some changes on the next iteration.

My familiarity with pan loaves is pretty much limited to Babka, which resides in a different universe from bread loaves.

thanks, Alan 

Benito's picture
Benito

For pan loaves, milk breads I really roll out quite flat and fine that gives a nice even crumb and they rise greatly when baked.  I also shape very tightly and that also doesn’t negatively affect the rise.

 

albacore's picture
albacore

When baking pan/tin loaves, I used to sit them directly on a bake stone, but after some experimentation I find I get better results if the tins are sat on one of the wire racks in the oven. I think the ability of the hot air to circulate gives a more even bake.

I do have a piece of steel plate 12" square by 3/8" thick and I put this in the oven about 2" below the wire rack to give some thermal mass to avoid too much temperature drop when the tins go in.

 

Lance

Benito's picture
Benito

For me, and I realize that everyone’s oven set up are different, I bake my pullman loaves directly on the baking steel on the lowest rack in my oven.  From the multitude of bakes I’ve done now with the milk breads I’ve found that I get the best oven spring in this location because this keeps the top of the loaf furthest from the radiant heat of the top of the oven and the bottom of the loaf gets the most direct heat from the steel.  Because the Hokkaido milk breads are so tall, I do a final bake out of the pan directly on the steel for an additional 10 mins sometimes dropping the temperature if the colour is already quite nicely browned.

In terms of pre shaping etc. if I have done a cold retard of some sort, I preshape and then give a brief rest of only 10 mins at most and then do final shaping.  I always allow the dough to rise to within 1 cm of the top of the pan before baking.

Ming's picture
Ming

I have actually experienced a similar problem if I use just a SD starter without instant yeast. If I mix a dough in my spiral mixture at a low to moderate speed, the dough would rise to a point 20-30% and then it would stall. If I mix it with a high speed then my SD starter would die and I get no rise at all. It seems like my SD starter does not like the centrifugal force of a spiral mixture. If I do not use a machine and hand knead the dough with my SD starter then it would be fine but it still takes 9-10 hours to double for being weak. With that said though, I do not recall seeing this problem with using instant yeast, but now that I think of it I have not tried a high-speed spin with instant yeast yet, might have to do that next to see what happen. 

Benito's picture
Benito

Yeah I don’t understand it really. I would have thought that the polish once well fermented, even if it started with a small inoculation of IDY, would be then completely been able to raise the final dough without any additional IDY. I’ve always assumed that additional IDY was added just to speed things up. So my wonder is whether or not adding some diastatic malt might help to increase the amylase in the final dough to ensure there are enough sugars for the microbes to feed on. When I see that pale top in addition to Doc’s comments it made me wonder if the sugars were insufficient either from over proofing or from lack of sufficient amylase activity. 

albacore's picture
albacore

As you may know, I am interested in historical recipes and there is a Scottish breadmaking system known as the quarter sponge method. In line with Scottish stereotypes (;-)), the idea is to use the least amount of yeast possible to raise the bread: 6oz fresh yeast per sack of flour (280lbs). So 0.054% idy equivalent.

The system involves an overnight stiff sponge, then a batter sponge for 1hr and finally a main dough for 1hr.

So 0.08% idy, should work, but I have tried the 1/4 sponge system a couple of times and I could never get it work to my satisfaction. The bread rose but never as tall or as airy a crumb as I wanted. Not sure why.

So I made it again and added 0.2% idy equivalent to the batter sponge and this gave vastly superior results and I won't be going back to ultra-low yeast rates.

If you want to persevere, you might try the multi step approach. Personally I also prefer sponges to poolish.

BTW I think the idea of a poolish is to develop fermentation flavours, increase extensibility and increase dough acidity, ie lower pH.

 

Lance

Doc.Dough's picture
Doc.Dough

Since yeast produces no lactate or acetate, the carbonic acid that results from dissolved CO2 is the likely source of any acid you find in a poolish. And the last time I measured the pH it was in the mid 5.xx range. I would be interested if you find another source of acid or a lower pH in either a poolish or a bigga without any LAB in the mix. 

mwilson's picture
mwilson

Doc we all know that dour sours.... perhaps you've heard the phrase Sour-dough?!

Forgive my humour, but actually yeast are perfectly capable of producing both lactic and acetic acid, perhaps just not in appreciable quantities in this context. But stress the yeast and you could certainly ramp up acetic acid production. That aside yeast pre-ferments do acidify and I believe the principal acid is succinic which is produced by the yeasts, along with carbonic and some lactic and acetic.

A further point of interest; for yeasted pre-ferments that exceed 12 hours we can expect spontaneous LAB to develop and contribute acetic and lactic acids.

I think the following is about right...

Mature 18-24hr / 48hr biga = pH 5.0-5.2
Mature 16hr poolish ~ pH 4.8

And one more thing Fresh yeast, since it is fresh can already be harbouring active LAB cells.

Doc.Dough's picture
Doc.Dough

Always happy to learn from you.  The only experience i have with commercial yeast and acid production has been when I was intentionally using CY to initiate a sourdough starter and wanted the carbonic acid pH reduction to help suppress leuconostoc while the more acid tolerant species gather in large enough quantity to take over.  I know that works, but I think of it as a special case.  If I am using CY it is to get a little more rapid CO2 production becaue my starter is not being optimally cared for.

Ming's picture
Ming

I have been using an old dough preferment made of both instant yeast and natural SD starter and to my surprise it has been more sour than my natural SD starter. I was kind of surprised that CY would coexist with LAB. 

a.peabody's picture
a.peabody

In theory, it should work to raise the entire bread with the pinch of yeast in the poolish. In practice...I've never tried it, partially because it's certainly not usual. Almost all IDY recipes begining with a poolish will instruct you to add 0.1%-0.3% more yeast when mixing the dough. I suspect the reason is that it just takes very long otherwise and also the goal of using a poolish is not generally to raise bread with as little yeast as possible.

If you're interested in experimenting to make it work, you might try either increasing the percentage of prefermented flour and/or increasing the hydration.

It's possible 6 hours just wasn't long enough for the amount of yeast.

MTloaf's picture
MTloaf

The title of this post is somewhat misleading. I inferred that you meant a baguette dough with a poolish and not the Bouabsa method with  a cold fermentation.

I am not steeped in science and rely more on intuition gained from experience. That being said I am guessing that the CO2 produced in the poolish is causing the yeast to be crippled or aged out. I think Marianna posted a graph of the various CY available and they all show a falling off point. In my limited experience with poolish it was hit or miss as to when the time was right to use it in the dough and yeast was always added in the final dough. 
The Giorlli ciabatta with a low hydration biga and no gluten development does not require additional yeast. I think a simple no knead bread recipe would work best for the pan loaf you are trying for. 
Don


Doc.Dough's picture
Doc.Dough

I was trying to figure out what the yeast numerical density might be and then realized that you didn’t tell us how much your poolish weighed or at what temperature it was fermented. 

My theory is that either there was not enough yeast to begin with or something slowed it down. Even without any supplemental DM there is alpha amylase added to the flour so there should be adequate maltose in the dough to feed any yeast in the mix. And adding the fresh flour to the poolish when you assemble the dough will bring another tranche. 

DanAyo's picture
DanAyo

PFF was 37.5%. It was fermented 12hr @ 76F using a good pinch (0.08%) yeast. No other additional  yeast was used for the bread. The poolish was light, jiggly, bubbly, and matured when mixed in the Final Dough.

Doc and others -
Do you agree that when a tiny amount of yeast is used in a poolish, that the mature poolish brings in huge amounts of yeast when incorporated in the Final Dough? In other words the original yeast multiply exponentially during the fermentation of the pre-ferment.

Doc.Dough's picture
Doc.Dough

What do you think the doubling time is for CY at 76°F?  That is suboptimal temperature so maybe 160 minutes? Accounting for no losses and no lag time, an initial innoculation of 0.08% might grow to the equivalent of 1.8% over 12 hrs (for the initial 37.5% of the flour with which you mixed the poolish).  Now add the remaining 62.5% of the flour and you drop the relative yeast to .6% of total flour or 1.2% of the fresh flour. It would be nice to know the weight loss of the poolish over that 12 hr period of time to better quantify the reasonableness of that approximation.

So it seems a little short to me and I have not included any factors that would tend to slow it down.  So that particular poolish does not bring  "huge amounts of yeast when incorporated in the Final Dough".   It might be low by a factor of 2 or 3 from where you would like to have it.  But then there is a decent chance that I have made a bad assumption, used a bad number, or made a math error, which makes all of this worth every cent you paid for it.

DanAyo's picture
DanAyo

Doc, I reasoned that since the wet (100% hydration) poolish tripled in 12hr @ ~76F that the yeast cells had multiplied considerably. There were numerous holes in the top of the levain so it was probably unable to rise anymore than that because of gas lost to the atmosphere. The bubbling of gasses could be heard if an ear was placed close to the top of the container.

Maybe next time I’l get a weight loss on the pre-ferment, if I remember. 

mwilson's picture
mwilson

For a Pullman loaf baked in a tin of 13 x 4 x 4, I have calculated I'd put about 900g of dough in there...

That is based on a baked weight specific volume of 4.5 ml/g and a 15% moisture loss.

Poolish, will rob your dough of strength, not what you want for any dough that needs to rise physically upwards. You need a dough that can create and contain a greater gas pressure.

Ming's picture
Ming

This theory makes most sense to me regarding this topic. 

DanAyo's picture
DanAyo

Mike, since I’m baking the dough in a pan (siders are supported) I though extensibility might be a good thing. 

The goal of this is to bake a bread with Ciabatta flavor, without giant holes in a pullman pan. In other words a great tasting sandwich bread with Ciabatta characteristics. 

I do remember that will baking for Ciabatta CB that your biga based Ciabatta was very successful.

Other than experienced bakers, who could imagine so many variations of breads using only flour, salt, and water…

albacore's picture
albacore

Have a look at this article; I believe it has relevant information.

You need to click on Factors Effecting Fermentation in the menu on the left.

Lance

DanAyo's picture
DanAyo

Mind Blowing article, Lance. But simplification requested to make sure this is properly understood.

The following excerpt is taken from your REFERENCED LINK.
 Factors Effecting Fermentation

Yeast Growth

Given the essentially anaerobic environment that exists in dough once the available oxygen is used, one would expect the primary physiological activity of yeast to be that of fermentation. However, the organism also undergoes some growth and cell multiplication during the fermentative process. For example, a test dough with a yeast content of 1.67%, based on flour, and fermented at 80° F (27° C), demonstrates no significant increase in yeast-cell count during the first two hours of fermentation with the actual rise in cell numbers being on the order of 0.003%. The most vigorous yeast growth was observed during the period between the second and fourth hours of fermentation, when the yeast cell count increased by 26%. Between the fourth and sixth hours, the rate of yeast multiplication declined again to about 9%, based on the original cell count.

Other findings indicate that the smaller the original quantity of yeast in the dough, the greater the percentage increase in cell numbers during the fermentation, with all other conditions being held constant. Thus a 0.5% yeast addition to a test dough produced an 88% increase in cell count after 6 hr of fermentation, while with a 2% original yeast level the corresponding increase in cell numbers was only 29%. This is not surprising given the fact that at the lower yeast level, the competition for nutrients is far less than at the higher yeast levels. Thus, each yeast cell has access or at least the opportunity for access to greater food supplies during fermentation.

Another study found that yeast growth in a sponge fermented for 4 hr was 56%, with only an additional 1% growth by the end of the proof period. The original yeast level of 2.25% was thus increased to 3.55% in the course of the entire fermentation. In a liquid preferment made with 3% yeast, the cell count increased by only 1% in the preferment, but by 15% in the dough. This reduced growth rate of yeast in liquid ferments accounts for the general practice of using higher original yeast levels in these doughs.

Not all work in this area is in agreement with the specific findings described above. Carlin, and then Reed, found no increase in the yeast population over a 4-hr fermentation period reporting essentially the same observations. It is rather difficult to determine the actual number of cells in a dough, it is relatively easy to establish the percentage of yeast cells that have buds. Compressed yeast will normally contain about 2 to 5% budding cells, and this number increases to about 30 to 50% by the end of the sponge fermentation, with no additional increase during dough fermentation. This increase in bud formation by the yeast cells is basically a sign of incipient yeast growth.

In the case of straight doughs, there is very little budding of yeast cells during the first three rises, but a substantial increase to about 40% during the proof period. No increase in the number of yeast cells was observed in liquid flour preferments, while budding was found in only about I8% of the cells after 3.5 hr of fermentation.”


Thinking that you understand something doesn’t necessarily make it so. I related the growth (rise) of a dough or pre-ferment as a relative indicator or cell multiplication. If my understanding of the above is correct, that is not the case. I thought a 3x or more growth was indicative of exponential cell multiplication. Evidently gas production is not a definitive indication of cell counts.

I hope others with understanding of the referenced link will share their understanding in a simplistic interpretation.

happycat's picture
happycat

Gee, sounds like an argument about the environment affecting reproduction :)

albacore's picture
albacore

I guess gas production is indicative of the yeast chomping away on the flour; firstly on any free sugars and then on sugars produced by amylolytic activity.

This gas production can happen without yeast growth. If there is yeast growth, then the rate of gas production will increase, assuming sugars are still available for fermentation.

DanAyo's picture
DanAyo

If I understand this latest line of reasoning correctly (and it is true), then it makes sense why additional CY is needed to increase the yeast cell population when mixing the Final Dough.

I love the process and journey of learning. This forum is an ultimate source of “all things bread” knowledge and does not discriminate towards anyone that is genuinely interested in learning. One does not need to be a genius or technically educated, only a willingness to inquire, share, and contemplate the information available.

Thanks all,
Danny

Doc.Dough's picture
Doc.Dough

We have words from a web site that acknowleges no capacity to perform experimental verification, contains no internal references (except for a hazy one to something that might have originated with Corriher), has a broken link to the bibliography and external links page, and has not been edited in 20 years.

Please explain to me why we should believe without evidence or rationale anything we find there.

albacore's picture
albacore

A somewhat harsh critique, Doc. The fact that material is 20 years old and not updated does not make it invalid.

I do accept that there should be working references. It looks like this part of the web site was never completed as it is not in the original version (Wayback Machine).

Some of the information appears to come from Pyler, Baking Science & Technology

Reference (16) refers to Hoffman C Schweitzer T R, Dalby Cereal Chem 18, 337 (1941)

 

Lance