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Author Topic: West Branch Malts  (Read 4639 times)

Big Monk

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Re: West Branch Malts
« Reply #30 on: July 05, 2019, 06:11:54 am »
The thing is, I'm not measuring for a1, a2, and a3 (though I'm an intermittent lurker on the HBT science board so I'm familiar with the concept.)  My method is a gross simplification.

Not as much as you think. Can you post some data from a recent batch so I can run some analysis?


I then simply assume, as a starting point, a buffering capacity of 32 mEq/(pH*kg) for the typical mash (which I'm sure I picked up somewhere attributed to work by Kolbach and has long been stuck in my head.)  Multiply through the desired shift in pH to get total mEq acid required, account for the total equivalent in (positive or negative  residual alkalinity * water volume), and what's left is to be supplied by my acid addition.  (Or the other way round in a dark beer requiring additional alkalinity.)  As I said,  this has been getting me right on target, probably within my margin for measurement.

Turns out that for RO/DI water as source, a1 (which is what you'd want to use in the linear equation in the absence of a2 and a3), Total Mash Buffering (mEq/dpH/kg) is roughly equal to a1.

This gets screwy when water with alkalinity is present but it could be a good way for you to use my sheet.

I'm just a practical brewer who wants to reliably predict mash pH, and this works far better than the available software (yours excepted, as I haven't tried it.)  Why my quick and dirty method so outperforms professional software is the next mystery.   Maybe some are overthinking?

Define "professional"?  ;)

You "back of the envelope" method works better because it's actually grounded in the science and mechanics of the mash better than others.

Offline Robert

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Re: West Branch Malts
« Reply #31 on: July 05, 2019, 07:09:40 am »
^^^^
Derek, here's the most recent batch, notes were handy and it's a convenient example because it's a single malt.

Note that I ignore the probable mineral content of the raw liquor, because my RO unit puts it out with only 5ppm TDS, and I also assume the pH reduction of 0.01/10ppm SMB as given on the LOB site.

I was looking for a room temperature mash pH of around 5.6 with this, but for convenience used nice round measures for water treatment to get "close enough."

9.5 lbs West Branch Pilsner, measured DI pH 5.88

Strike 3.75 gal RO w/ 0.3 g/gal gypsum 0.6 g/gal calcium chloride dihydrate  50ppm SMB 1.4 mL lactic acid 88% (and AA and BtB but I assume those are irrelevant.)

I predicted, back of the envelope as you say, room temperature mash pH 5.62.

Actual room temperature mash pH 5.60.

[FWIW BW predicts 5.34.]

Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Big Monk

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Re: West Branch Malts
« Reply #32 on: July 05, 2019, 07:25:50 am »
^^^^
Derek, here's the most recent batch, notes were handy and it's a convenient example because it's a single malt.

Note that I ignore the probable mineral content of the raw liquor, because my RO unit puts it out with only 5ppm TDS, and I also assume the pH reduction of 0.01/10ppm SMB as given on the LOB site.

I was looking for a room temperature mash pH of around 5.6 with this, but for convenience used nice round measures for water treatment to get "close enough."

9.5 lbs West Branch Pilsner, measured DI pH 5.88

Strike 3.75 gal RO w/ 0.3 g/gal gypsum 0.6 g/gal calcium chloride dihydrate  50ppm SMB 1.4 mL lactic acid 88% (and AA and BtB but I assume those are irrelevant.)

I predicted, back of the envelope as you say, room temperature mash pH 5.62.

Actual room temperature mash pH 5.60.

[FWIW BW predicts 5.34.]

So...

My water troubleshooter predicts 5.669 - 0.05 (SMB) = 5.619



I matched your values and set the malt at 5.88 pH DI with an a1 value close to the mash buffering.

Summary:

QWater (mEq) = 0.0303
QAlkalinity (mEq) = -0.3605
QMalt (mEq) = 29.0526
QCalcium (mEq) = -12.4792
QLactic (mEq) = -16.2432

pHz = 5.669 (the value that zeros QTotal)

SMB Δ pH = 0.05

pHz  = 5.669 - 0.05 = 5.619

If I flick the selector from dihydrate to anhydrous for CaCl:

QWater (mEq) = 0.0318
QAlkalinity (mEq) = -0.3642
QMalt (mEq) = 31.8824
QCalcium (mEq) = -15.3187
QLactic (mEq) = -16.2313

pHz = 5.649 (the value that zeros QTotal)

SMB Δ pH = 0.05

pHz  = 5.649 - 0.05 = 5.599

« Last Edit: July 05, 2019, 07:30:48 am by Big Monk »

Offline Robert

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Re: West Branch Malts
« Reply #33 on: July 05, 2019, 07:46:09 am »
^^^^
Derek, here's the most recent batch, notes were handy and it's a convenient example because it's a single malt.

Note that I ignore the probable mineral content of the raw liquor, because my RO unit puts it out with only 5ppm TDS, and I also assume the pH reduction of 0.01/10ppm SMB as given on the LOB site.

I was looking for a room temperature mash pH of around 5.6 with this, but for convenience used nice round measures for water treatment to get "close enough."

9.5 lbs West Branch Pilsner, measured DI pH 5.88

Strike 3.75 gal RO w/ 0.3 g/gal gypsum 0.6 g/gal calcium chloride dihydrate  50ppm SMB 1.4 mL lactic acid 88% (and AA and BtB but I assume those are irrelevant.)

I predicted, back of the envelope as you say, room temperature mash pH 5.62.

Actual room temperature mash pH 5.60.

[FWIW BW predicts 5.34.]

So...

My water troubleshooter predicts 5.669 - 0.05 (SMB) = 5.619



I matched your values and set the malt at 5.88 pH DI with an a1 value close to the mash buffering.

Summary:

QWater (mEq) = 0.0303
QAlkalinity (mEq) = -0.3605
QMalt (mEq) = 29.0526
QCalcium (mEq) = -12.4792
QLactic (mEq) = -16.2432

pHz = 5.669 (the value that zeros QTotal)

SMB Δ pH = 0.05

pHz  = 5.669 - 0.05 = 5.619

If I flick the selector from dihydrate to anhydrous for CaCl:

QWater (mEq) = 0.0318
QAlkalinity (mEq) = -0.3642
QMalt (mEq) = 31.8824
QCalcium (mEq) = -15.3187
QLactic (mEq) = -16.2313

pHz = 5.649 (the value that zeros QTotal)

SMB Δ pH = 0.05

pHz  = 5.649 - 0.05 = 5.599
So, we got the same result (yeah my prediction was 5.619 etc but I round off)!  Now, having repeatedly read through the sticky on HBT, and being unmotivated to go through all the process laid out, and my head set spinning by AJ's raw code for Excel... I have no idea how to determine a specific a1 or mash buffering.  If it's really simple, let me know.  But my placeholder 32 mEq/(pH*kg) seems to work (I assume it came from work Kolbach did on a very narrow range of standard Pilsner mashes, so I might just be lucky since most of my grain bills are pale/Pilsner based.)  With the actual measured pH within 0.02 of my prediction, and my meter's stated accuracy being +/- 0.05 with 0.01 resolution,  I don't see much point in trying to refine this much -- I'm willing to accept a pH anywhere within +/- 0.5 of target.  So while your sheet would probably progressively refine my results, I'm also happy with my quick and dirty approximation for now, unless you see some fatal flaw that just hasn't reared its head yet. (Like most things, if I determine there's a simple formula that will generally apply, I'll probably make my own little calculator in Excel on my phone, though tapping it all out on the old calculator every time is no big hassle.)  I really appreciate your help.
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Big Monk

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Re: West Branch Malts
« Reply #34 on: July 05, 2019, 08:19:33 am »
Now, having repeatedly read through the sticky on HBT, and being unmotivated to go through all the process laid out, and my head set spinning by AJ's raw code for Excel... I have no idea how to determine a specific a1 or mash buffering.

Well, the great thing about having worked through the original raw code A.J. posted with him was that he then developed a set of callable VBA functions that I then modified for the current troubleshooter. It really is very simple to use and does what you are doing but likely a bit faster.

Short of titrating the malt, which is the method for determining the co-efficients, you can guess. If you take a look at my sheet, you'll there are 10 "Custom Malt Parameters" slots in the Malt Type Database. I added 2 new cells and I will upload the revision to the main site shortly:

1.) Total Mash Buffering (mEq/Δ pH)
2.) Total Mash Buffering (mEq/Δ pH/kg)

I believe the second value is what you have been targeting.

For RO/DI water, which it seems like you are using, I think it's safe to assume that

Total Mash Buffering (mEq/Δ pH/kg) = a1 insofar as the values you are predicting are close to what you are measuring.


I really appreciate your help.

No problem. A.J. was very patient with me when some of the threads came about last year and I think he was happy to finally have someone who understood and could "pretty" things up for public consumption.

The biggest hurdle is really malt modelling. The model is simple:

dQmalt (mEq/kg) = a1 * (pHz - pH DI) + a2 * (pHz - pH DI) ^ 2 + a3 * (pHz - pH DI) ^ 3

The issue is getting a1, a2, and a3 but the savvy homebrewer can tweak the inputs in my sheet to get decent data after a few batches with the same malt.

I would suggest tweaking for base malts and using my stock values for specialty malts.

Ultimately, the concept of charge conservation/proton deficit is that all the Q values of the contributors (QTotal) need to be zero'd out by a value of pHz (mash pH estimate). Excel is our friend here. You can use the solver to tell the sheet specific values of acid, etc. or you can do like A.J. did (and that I adapted) and put code in that does it when you change a variable.

Either way, "following the protons" (as A.J. says) is a much better way than color proxies, etc. Also, by taking into account the pH dependence for things like acids, baking soda, lime, etc., you eliminate incremental errors that plague sheets that can't track pH dynamically.
« Last Edit: July 05, 2019, 09:47:27 am by Big Monk »

Offline Robert

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Re: West Branch Malts
« Reply #35 on: July 05, 2019, 08:54:31 am »
So if I understand, by your definition 2.) Total mash buffering, a refined figure in my present case, rather than 32 mEq/(pH*kg) would be ~29.89 mEq/(pH*kg) for this Pilsner malt?  Then going back over a couple of other batch records, I'd work out the buffering for the West Branch Pale Ale malt to be ~38.1 mEq/(pH*kg).  I can use these assumed values going forward, but I notice they still leave a bit of discrepancy on a couple of batches as recorded, and that my default 32 for an unknown malt is also still nearly as close *in practical terms.*   As a starting  point.  (Dosing of salts and acids in such small quantities is also a source of error no doubt.)  So I will refine my method.  I could, when I test DIpH of a new malt, then just add a given amount of acid to get an approximation of this more specific buffering value.   Or just follow my pragmatic inclination, and revise my assumptions based on actual batch results.  Thanks again.
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Big Monk

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Re: West Branch Malts
« Reply #36 on: July 05, 2019, 09:11:49 am »
So if I understand, by your definition 2.) Total mash buffering, a refined figure in my present case, rather than 32 mEq/(pH*kg) would be ~29.89 mEq/(pH*kg) for this Pilsner malt?  Then going back over a couple of other batch records, I'd work out the buffering for the West Branch Pale Ale malt to be ~38.1 mEq/(pH*kg). 

Here is what I did:

1.) Zero out all charge/proton contributors

2.) Calculate Total Mash Buffering (mEq/Δ pH) = -137.88

3.) Calculate Total Mash Buffering (mEq/Δ pH/kg) = -137.88/4.31 = -31.98

Since the mEq contributions of pure water and alkalinity are so low in your case, and there are no other charge/proton contributions (minerals at zero, no acids, etc.), it is a relatively safe assumption to say all the mash buffering is malt based. So we use -31.98, rounded to -32 as a1.

Now I add back your minerals (assuming both dihydrate and anhydrous forms of CaCl)and acid contribution. We know your measured pH was around 5.60 and if I adjust for the Meta you used, my prediction becomes:

Estimated pHz (Dihydrate CaCl) = 5.671 - 0.05 = 5.621
Estimated pHz (Anhydrous CaCl) = 5.651 - 0.05 = 5.601

The value for Total Mash Buffering (mEq/Δ pH/kg) only changes to -32.12 with the addition of your minerals and acid. So, for the case of RO/DI water, we can assume that the Total Mash Buffering (mEq/Δ pH/kg) value can be a stand in for a1 of the base malt.

Not perfect but convenient.

I can use these assumed values going forward, but I notice they still leave a bit of discrepancy on a couple of batches as recorded, and that my default 32 for an unknown malt is also still nearly as close *in practical terms.* As a starting  point.

I don't think you need to change anything. My analysis above shows that -32 works. You can use my sheet and take some of the guesswork out of what you are currently doing.

Obviously water with low to moderate alkalinity will make the assumptions and correlations above not ring true but for your purposes you can pull down my sheet and use if for the same type of analysis you've already been doing. Also, different malts may give deviations from this assumptions as well.

Always let the protons be your guide...
« Last Edit: July 05, 2019, 09:38:11 am by Big Monk »

Offline Robert

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Re: West Branch Malts
« Reply #37 on: July 05, 2019, 09:34:13 am »
What I've been after is simply a way to empirically, cumulatively predict what will happen in the next mash.   I'd at some point intuited some of what you've laid out (regarding total mash buffering) but not fully incorporated it.  I think I've taken a great leap forward here.  Thanks again again.
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Big Monk

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Re: West Branch Malts
« Reply #38 on: July 05, 2019, 09:49:28 am »
What I've been after is simply a way to empirically, cumulatively predict what will happen in the next mash.   I'd at some point intuited some of what you've laid out (regarding total mash buffering) but not fully incorporated it.  I think I've taken a great leap forward here.  Thanks again again.

In this case it seems you were simply lucky to have settled on a value for mash buffering that pretty closely approximates the a1 value for the malt you used.

It won't always work out like that but at least now you have a troubleshooting tool you can use to get useful estimations.

Offline BrewBama

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Re: West Branch Malts
« Reply #39 on: July 10, 2019, 09:13:43 pm »
True, this is the 2nd batch since I've implemented my full low oxygen hot side procedures.  Still, the malt is exemplary in itself, I'm just taking fullest advantage of it.

Do you Oxygen Scavenge your Strike water (and if applicable Sparge water) with yeast and dextrose the night before or do you boil and cool prior to dosing with Metabisulfate?


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Offline Robert

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Re: West Branch Malts
« Reply #40 on: July 10, 2019, 09:27:28 pm »
I use yeast scavenging.  I do my general setup and water treatment the night before so I can get an early start.  So I PM'd Bilsch to get an idea whether I could go with adding the yeast the night before.  He said that in his tests, the indications were that yeast could scavenge oxygen much faster than it could be taken up from the atmosphere even in an uncovered vessel,  so that 12 hours would probably be perfectly fine, though he didn't have data out beyond that range.   But he also said that it could go to <0.5ppm in just 30 minutes and <0.2ppm in not much more.  So my SOP now is to get up, feed the cat, toss in the yeast and dextrose, have a quick breakfast and look at the sports page, and get brewing.  If you don't have a cat, skip that part.  All evidence is that this works perfectly.
 
EDIT (It's probably about 1.5-2.5 hours from dosing till my water hits the temperature that will kill the yeast, though I assume it's most active right there at the end.   I dose the SMB, AA and BtB 5 minutes before mashing in. )

FURTHER EDIT I do sparge.  Dose yeast at the same time as strike liquor after feeding cat, add desired SMB just before commencing sparge.  Also relevant to all this, I use a mash cap, lauter cap (I mash in kettle with direct fire for steps, transfer to LT) and a cap on the sparge liquor in the "HLT."  Caps are, of course, floating cake pans.
« Last Edit: July 10, 2019, 10:44:59 pm by Robert »
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline BrewBama

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Re: West Branch Malts
« Reply #41 on: July 11, 2019, 05:26:48 am »
Thx. I’m having trouble finding a floating cake pan for my blue rectangle cooler.


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Offline Robert

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Re: West Branch Malts
« Reply #42 on: July 11, 2019, 05:57:20 am »
Thx. I’m having trouble finding a floating cake pan for my blue rectangle cooler.


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What are the dimensions?  You need to leave a little space around the edges or you can't grab it to get it in and out anyway.   If not one, two of some size would probably fit.  If not high sides cake pans (harder to sink by accident) maybe regular sheet pans.  Or something.  The goal is just to cover as much surface area as possible, to reduce atmospheric uptake as much as possible.  Possible being the operative word.  It's another incremental step in tightening everything up.


EDIT

Hey wait a minute BrewBama... aren't you just a little bit handy with sheet metal? 
« Last Edit: July 11, 2019, 06:14:43 am by Robert »
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline Robert

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Re: West Branch Malts
« Reply #43 on: July 12, 2019, 01:09:41 pm »




Do you Oxygen Scavenge your Strike water (and if applicable Sparge water) with yeast and dextrose the night before or do you boil and cool prior to dosing with Metabisulfate?






I use yeast scavenging.  I do my general setup and water treatment the night before so I can get an early start.  So I PM'd Bilsch to get an idea whether I could go with adding the yeast the night before.  He said that in his tests, the indications were that yeast could scavenge oxygen much faster than it could be taken up from the atmosphere even in an uncovered vessel,  so that 12 hours would probably be perfectly fine, though he didn't have data out beyond that range.   But he also said that it could go to <0.5ppm in just 30 minutes and <0.2ppm in not much more.  So my SOP now is to get up, feed the cat, toss in the yeast and dextrose, have a quick breakfast and look at the sports page, and get brewing.  If you don't have a cat, skip that part.  All evidence is that this works perfectly.
 
EDIT (It's probably about 1.5-2.5 hours from dosing till my water hits the temperature that will kill the yeast, though I assume it's most active right there at the end.   I dose the SMB, AA and BtB 5 minutes before mashing in. )

FURTHER EDIT I do sparge.  Dose yeast at the same time as strike liquor after feeding cat, add desired SMB just before commencing sparge.  Also relevant to all this, I use a mash cap, lauter cap (I mash in kettle with direct fire for steps, transfer to LT) and a cap on the sparge liquor in the "HLT."  Caps are, of course, floating cake pans.

RE:  my yeast scavenging protocol given above.   Brewing tomorrow morning.   Think maybe this time I'll try dosing the yeast and dextrose tonight when I set up, and leave the vessels capped.  Just to see if it makes any difference either to my convenience, or to the actual effect (not entirely sure how I'd determine that.)
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline Robert

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Re: West Branch Malts
« Reply #44 on: July 13, 2019, 09:54:47 am »
^^^^
Well, that at least got me an even earlier start, which could be handy in the summer when I don't want brewing to go too far into the heat of the day.

Otherwise -- lacking a DO meter -- indicators like lack of mash smells and flavor of wort suggest the two timing methods are equally viable.
« Last Edit: July 13, 2019, 09:56:28 am by Robert »
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.