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### Author Topic: Baker's yeast quantity prediction model - please compare to your results  (Read 171382 times)

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#### 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

#### 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.
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### 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

#### 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.
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### 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.

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#### 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
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### 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.

#### 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.

#### 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

#### 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 3°C for 26 hours. These 26 hours represent about 1/8 of the total "calculated" fermentation time at 3°C. Now I intend to ball the dough and let the balls rise at 16°C. The total fermentation time at 16°C 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 16°C for "only" 31 and 1/2 hours ? I mean my calculation is 1/8 at 3°C and 7/8 at 16°C.
I hope I'm clear in my request...

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#### 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.
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### 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 3°C, there should be about 28 hours left at 16°C ?

#### 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 3°C, there should be about 28 hours left at 16°C ?

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.
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### 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

#### 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 !...

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#### TXCraig1

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##### Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #75 on: November 02, 2013, 07:24:37 PM »
Here is the revised model. I think this will get you to a pretty good starting point with most formulations.

Please let me know your results.
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### blaise

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##### Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #76 on: November 03, 2013, 03:10:57 AM »
I will !
Thanks a lot

#### Needssalt

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##### Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #77 on: November 15, 2013, 11:31:15 AM »
Around .021+% ADY at about 73 deg,.... baked dough sample rolls at 22hrs.  could have gone another 1 or 2.  Fits right in there.  It's so cool.  I have some multiple temp balls rising now, baking tomorrow and Sunday.  Will post.   Thanks for this.

#### TXCraig1

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##### Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #78 on: November 15, 2013, 11:40:53 AM »
Around .021+% ADY at about 73 deg,.... baked dough sample rolls at 22hrs.  could have gone another 1 or 2.  Fits right in there.  It's so cool.  I have some multiple temp balls rising now, baking tomorrow and Sunday.  Will post.   Thanks for this.

Thanks for the data. That fits right with the model.

The goal is really to just give a good starting-point yeast estimate. I expect some formulations/workflows will require some tweaking of the model results, but in general this should get you pretty close - a lot closer than a SWAG.
"We make great pizza, with sourdough when we can, baker's yeast when we must, but always great pizza."
Craig's Neapolitan Garage

#### Needssalt

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##### Re: Baker's yeast quantity prediction model - please compare to your results
« Reply #79 on: November 16, 2013, 04:52:37 PM »
Just another update.  The green on the chart is where I ended up. Right in there again.  I highlighted double boxes to account for some fluctuations and +/-.

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