Author Topic: Baker's yeast quantity prediction model - please compare to your results  (Read 33596 times)

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Offline juniorballoon

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #50 on: September 19, 2013, 06:38:12 PM »
Good to know, Next time I'll get it right. Funny thing is my wife heard the lids popping off in the middle of the night and thought someone was breaking in. :)

Thanks,
jb


Offline JConk007

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #51 on: September 19, 2013, 11:44:44 PM »
.11 IDY 60%  last Night  temps  low 60's 7 hours not dough was quite there
Last week  .14 with low 70s was right on your table data. Tonights dough for saturday did .12 and temps  63-65 will be about 12 hour bulk  time I get to ball it. I will provide pics in am.
From What I am seeing the data you have  is quite close to actual "ready times"
I do extend in the fridge after this initialferment based on  space, room  temps, and what I have going on gfor the weekend. 
This is  a  great guide/tool !! will try cake yeast also and post results
thanks craig!
John
« Last Edit: September 19, 2013, 11:47:03 PM by JConk007 »
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Offline henkverhaar

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #52 on: September 20, 2013, 04:30:04 AM »
This isn't a growth model. It's a rate model. Resources are not a constraint. There are ample resources by definition. It's not time dependent; it's temperature dependent.

Your model is a rate model because you use the temperature as your independent variable, but it's still governed by the same underlying process. I was merely trying to say that 'exponential' growth is a 'special case' of logistic growth, valid under conditions were there are no resource constraints yet. In the sense that the exponential part of your model does in fact represent something more than just being a convenient function that happens to fit the data...
;-)

Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #53 on: September 20, 2013, 10:14:16 AM »
.11 IDY 60%  last Night  temps  low 60's 7 hours not dough was quite there
That was similar to my findings.  This is a tremendous idea Craig.  I will continue to generate some data.   Mark

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #54 on: September 20, 2013, 10:46:46 AM »
Your model is a rate model because you use the temperature as your independent variable, but it's still governed by the same underlying process. I was merely trying to say that 'exponential' growth is a 'special case' of logistic growth, valid under conditions were there are no resource constraints yet. In the sense that the exponential part of your model does in fact represent something more than just being a convenient function that happens to fit the data...
;-)


Yes, exponential growth is an underlying assumption no doubt about that but not as you stated in your comments with respect to the specific functioning of the model. Perhaps some of the confusion is that I was not particularly clear in my original response to you that I was only talking about the specific part of the model Jim asked about not the model as a whole.

You mischaracterized how the model functions when you responded to my comment about a specific ex term writing It represents exponential growth and you mischaracterized it again here when you stated that this specific term as used represents more than a convenient function to fit the data. It does not.

The part of the model you commented on simply describes the effect of temperature on a relative growth rate. Its time independent, in fact, the dependant variable is dimensionless.  The function in question does not represent exponential growth (which always has time as an independent variable and a dependent variable with a dimension that represents a quantity of some sort such as number of cells or cell mass).

I think you are confusing the exponential function with exponential growth. The particular term in question is simply part of a larger function that describes how yeast growth rate varies with temperature, the result of which is used in the larger model which incorporates an exponential growth assumption.
« Last Edit: September 20, 2013, 10:50:23 AM by TXCraig1 »
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Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #55 on: September 21, 2013, 07:25:59 AM »
IDY 0.073%. 63% hydration 12 hours.  I think these are just beginning to be ready - baking 14 pies for marching band at noon.    Mark

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #56 on: September 21, 2013, 08:29:45 AM »
Thanks Mark.
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Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #57 on: September 21, 2013, 08:44:25 AM »
Thanks Mark.
you are welcome Craig - thank you for your efforts.   Dough at 14 hrs :

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #58 on: September 21, 2013, 10:34:16 AM »
you are welcome Craig - thank you for your efforts.   Dough at 14 hrs :

Would you say that dough was ready at 12-13 hours?
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Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #59 on: September 21, 2013, 04:24:07 PM »
Would you say that dough was ready at 12-13 hours?
yes Craig,  I would say that 12 to 13 hours was the beginning of when the dough was ready, but at 14 hours it was excellent, as the pic indicated.  And it still was in the "good window" for another hour or two.  I think there is a 3 or 4 hour window - none of my pics show dough as "ripe" as others have posted.  Cranked out 14 pies at marching band tailgate party - all pies were gone in seconds after being pulled from oven

Offline deb415611

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #60 on: September 22, 2013, 07:42:17 AM »
loving this chart Craig  :)

chart 77 degrees. 6 hours .064 IDY

was 77 when dough made, 78 every other time I checked time (which is still 6 hours)

100% flour, 63% water, 1.75% salt, 1% sugar, 3% oil

pic 1 at 3 hours
pic 2 at 5 hours
pic 3 at 6 1/4 hours
pic 4 middle pizza was probably baked around 6:45


« Last Edit: September 22, 2013, 07:48:54 AM by deb415611 »
Deb

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #61 on: September 22, 2013, 08:52:48 AM »
Thanks Deb. These posts are a big help. A revised, fine tuned chart is coming soon.
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Offline henkverhaar

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #62 on: September 24, 2013, 04:08:45 AM »
I think you are confusing the exponential function with exponential growth. The particular term in question is simply part of a larger function that describes how yeast growth rate varies with temperature, the result of which is used in the larger model which incorporates an exponential growth assumption.

No, I'm not confusing exponential growth and the exponential function. But other than that, hmmm, I think that I'd have to admit that, hmmm, maybe you're right. Now how's that for noncommittal...

However, if so, can we than perhaps agree that your exponential dependence of rate on temperature (expressed as Tmax-T) is in fact a form of the Arrhenius equation? Arrhenius equation generally applies to simple chemical reactions, but is often used as a useful, if not necessarily exact, model to describe the dependence of microbial metabolism on temperature (such as the rate of microbial degradation of contaminants in soil dependent on soil temperature).

Cheers

Henk

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #63 on: September 24, 2013, 10:30:07 AM »
However, if so, can we than perhaps agree that your exponential dependence of rate on temperature (expressed as Tmax-T) is in fact a form of the Arrhenius equation? Arrhenius equation generally applies to simple chemical reactions, but is often used as a useful, if not necessarily exact, model to describe the dependence of microbial metabolism on temperature (such as the rate of microbial degradation of contaminants in soil dependent on soil temperature).

I think you are trying to read too much into it. It's like Arrhenius in that it's a function that describes a non-linear relationship between temperature and rate at which something happens, but unlike Arrhenius which describes a relationship between meaningful quantities - the activation energy, average kinetic energy, frequency of collisions, and geometry of the molecule - Ganzle is simply a curve fit to observational data.
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Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #64 on: October 05, 2013, 11:34:45 AM »
.05% IDY  16 hours at 66.  Not quite there.  More pics to follow later in day.

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #65 on: October 05, 2013, 02:03:28 PM »
.05% IDY  16 hours at 66.  Not quite there.  More pics to follow later in day.

For some reason, both the original model and the revision I've been working on tend to come up short in the 66-68F range. The other points look pretty good in the new model I'm still tweaking
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Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #66 on: October 05, 2013, 02:37:29 PM »
19 hours.  My SAF yeast is not expired but has been properly refrigerated for 6 months in sealed glass. 


Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #67 on: October 05, 2013, 05:00:00 PM »
21 hours. I am going to put in fridge for party at 6 Pm. Baking 12 pies. I would say window is 19 to 21 hours.

Offline communist

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #68 on: October 05, 2013, 08:42:08 PM »
After baking pies, 21 hour dough a bit too long fermenting.  I think next time I will time dough for use at 19 hours.  This is only 2 or 3 hours beyond predicted, but that has been my findings in the past

Offline blaise

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #69 on: October 29, 2013, 05:05:15 AM »
A revised, fine tuned chart is coming soon.
Hi Craig
Any news regarding this "new" fine tuned chart ?
On the other hand, can you please give me your opinion about sort of calculation ? I prepared a CY dough at 0,1% and put the bulk into the fridge at 3C for 26 hours. These 26 hours represent about 1/8 of the total "calculated" fermentation time at 3C. Now I intend to ball the dough and let the balls rise at 16C. The total fermentation time at 16C is supposed to be about 36 hours. Is it relevant to withdraw 4 and 1/2 hours (which are 1/8 of 36 hours) and let the balls rise at 16C for "only" 31 and 1/2 hours ? I mean my calculation is 1/8 at 3C and 7/8 at 16C.
I hope I'm clear in my request... ???

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #70 on: October 29, 2013, 09:25:31 AM »
You might want to take off the 4.5 hours. I just looked at what the new model predicts, and it is about 27-28 hours.

I haven't had a chance to work on the new model lately. Hopefully soon.
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Offline blaise

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #71 on: October 29, 2013, 10:51:33 AM »
You might want to take off the 4.5 hours. I just looked at what the new model predicts, and it is about 27-28 hours.
Craig,
Do you mean that after the 26 hours at 3C, there should be about 28 hours left at 16C ?

Offline TXCraig1

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #72 on: October 29, 2013, 11:11:17 AM »
Craig,
Do you mean that after the 26 hours at 3C, there should be about 28 hours left at 16C ?

Yes. That is what the new model says right now. I may tweak it some more, but in nay case, I'm pretty confident that the original model predicts times that are too long when the fermentation is cold.
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Offline blaise

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #73 on: October 29, 2013, 11:25:40 AM »
Thank you so much for your reply  ;D

Offline blaise

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Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #74 on: October 30, 2013, 03:33:57 AM »
That is what the new model says right now.
Craig,
Would you have anything that you can share ? Or is it "just" very complicated formulas that I wouldn't understand or master anyway !...