Help Needed with the Water Chemistry (part 2)

[dmcmillen]

I thought it would be better to start a new thread since the original thread seems to have run its course with a discussion about the acidity of the Brown Malt.

To recap, I am getting ready to brew a simple two grain porter recipe that calls for 6.25# Maris Otter (3L) and 3.6875# (65L) Brown Malt. I made the original post because I was confused with the Bru'n Water pH prediction of 5.18. I did test the Brown Malt and came up a 5.15 as a dipH, but I am since doubting that reading since I was recording the pH from the MW102 as soon as the hour glass disappeared as per the meter instructions. Since then, with AJ's help I now understand how to take the reading.

I just did a .75# test mash with my water (Alk 98, Bicarb 119, SO4 9, Cl 4, Na 28, Ca 9, Mg 4) with both grains and scaled down CaCl addition to yield 50ppm Ca. Note that this addition turns out to be very close to the AJ's recommendation of 1 teaspoon of CaCl or 3.6g CaCl anhydrous. Going into this test I expected the pH to be low and require some bicarbonate to raise the pH.

Note that I calibrate the meter each time just before testing and I performed stabilization tests a few weeks ago. Here's what I experienced:

Test 1 - Sample taken after 20 min and cooled --> After stirring & reading several times reading stabilized at about 5.50 (note that this took about 10 - 15 mins to finally stabilize; I can't imagine how that's going to affect my brew day)

Test 2 - Same sample (covered with tin foil) the next morning. Stabilized at 5.60.

Test 3 - A 2nd sample taken from the cooled down mash before cleaning up. Test done on day 2. Stabilized at 5.40.

So I have three readings of 5.50 (20 mins into mash),5.60 (same sample next day), and 5.40 (2nd sample). I would appreciate some direction here. Is this expected behavior? Not?

 

[ajdelange]

This just doesn't make any sense at all. You are mixing malts with DI pH of about 5.14 and 5.6 or higher with water with almost 2 mEq/L alkalinity and coming up with mash pH that is appreciably less the DI mash pH of the most acidic component. This cannot happen. In such cases I am always suspicious of the pH reading so that the only advice I can offer at this point is to check the meter (including its stability) gain and if everything is OK repeat the experiment.

 

[dmcmillen]

AJ, of course that doesn't make any sense. I typed in 4. instead of 5. It was 5.50, 5.60 and 5.40. Funny how the brain works (or doesn't); hit me at lunch). So, same questions?

 

[ajdelange]

Well that's a horse of a different color. It's a little disquieting that the three readings span 0.2 pH but at least each of them is feasible.

 

[RPh_Guy]

CaCl addition to yield 50ppm Ca.

Is this right? You're adding 100ppm chloride?

 

[ajdelange]

Adding 50 ppm Ca from CaCl2 adds 50/20 = 2.5 mEq calcium and 2.5 mEq Cl which 88.5 ppm.

 

[RPh_Guy]

Adding 50 ppm Ca from CaCl2 adds 50/20 = 2.5 mEq calcium and 5 mEq Cl which 177 ppm.

Yes, thanks. My chemistry is pretty rusty. Does adding 177 ppm chloride seem high?

 

[ajdelange]

It would to many.

 

[dmcmillen]

Bru'n Water calculated 1.6g CaCl for the full mash water, which, per Bru'n Water, added 41 ppm Ca and 73 ppm Cl to my existing water for a total of 50 ppm Ca and 77 ppm Cl. I scaled the 1.6g back for my test mash water. Bru'n Water's calculated CaCl for the sparge was 2.15g, bringing the total addition to 3.75 g, close to the one teaspoon recommended by AJ in the Primer sticky which as I understand from the sticky conversation is 3.6g anhydrous CaCl. Is Bru'n Water not calculating this correctly?

Also, what I'm really trying to understand is why my test readings range from 5.4 to 5.6, the 5.4 test on the mash that was collected at the end of the test session, the heat having been turned off at 20 mins and setting there for probably another 30 to to 40 mins, then testing the next day. Testing the original sample immediately after 20 mins and cooling was 5.50 and testing again the next morning was 5.60. Is that a reasonable change to expect? It was the same sample.

 

[ajdelange]

Yes, thanks. My chemistry is pretty rusty. Does adding 177 ppm chloride seem high?

Don't thank me as I was wrong. 2.5 mEq of calcium from calcium chloride gives 2.5 mEq of chloiride. They're equivalent! Doh. 2.5 mEq of chloride is 88.5 ppm

 

[RPh_Guy]

Don't thank me as I was wrong. 2.5 mEq of calcium from calcium chloride gives 2.5 mEq of chloiride. They're equivalent! Doh. 2.5 mEq of chloride is 88.5 ppm

LOL, I was wrong in any case. Sounds like maybe we're both more used to dealing in mol.

@dmcmillen
If it makes you feel any better, mash pH doesn't seem to have a discernable sensory effect on the finished beer, or at least in the beers evaluated by the brulosphy folks.
http://brulosophy.com/2017/07/24/wa...e-impact-of-high-mash-ph-exbeeriment-results/
http://brulosophy.com/2017/01/30/wa...he-impact-of-low-mash-ph-exbeeriment-results/

The various mineral levels however do seem to play a more prominent role:
Sulfate to chloride ratio seems to be the most important stylistic target related to water chemistry.
Sodium is detectable and has some kind of effect.
Removing alkalinity from sparge water is important, especially for fly sparging.

Considering how much I've seen mash pH shift in a matter of 40 minutes, I'm not surprised to see you getting different measurements at different times. Personally I don't stress out about it since learning its effect may be negligible, especially if I'm in the right ballpark.

 

[Silver_Is_Money]

I thought it would be better to start a new thread Going into this test I expected the pH to be low and require some bicarbonate to raise the pH.

Your confusion seems to stem from simply not understanding or accepting that with a rather high 98 ppm of alkalinity sufficient to somewhat more than sufficient alkalinity/bicarbonate is already present within your water, and additional is therefore not required. That plus seemingly having more confidence in a particular 'outlier' software packages prediction of 5.18 mash pH than in your own measurements, and in the fact that most all other of such available software capable of accepting DI_pH values (plus the computational science of A.J. DeLange) would more than likely have told you right up front that your mash pH would fall somewhere within in the highly acceptable range of 5.4 to 5.6 pH for a porter, precisely as you have confirmed via measurement.

Software that I'm aware of (in addition to my own) that is capable of accepting directly measured DI_pH value inputs from the user includes Brewer's Friend, Low O2 Brewing, and EZ Water. For the latter, most do not understand that it is possible to input your own DI_mash pH values and override the defaults, as this is not really made clear or intuitive within the software itself.

 

[ajdelange]

Is Bru'n Water not calculating this correctly?

I'm sure it is calculating correctly for whatever form it assumes the CaCl2 to be in. When I wrote the Primer I probably assumed that the stuff we buy was the dihydrate because that is usually what is sold in reagent grade. This was way before I got around to checking what is actually in the bottles we buy and what we find in them when we open them after the first time. Plus how much is a teaspoon? 4.5 grams? 5 grams? If you really want to know how much CaCl2 you are adding you will have to add it as a solution whose specific gravity you have measured.

Testing the original sample immediately after 20 mins and cooling was 5.50 and testing again the next morning was 5.60. Is that a reasonable change to expect? It was the same sample.

It is reasonable to expect mash pH to drift. In cases where acid has been added you can expect it to drift up but where base has been added you can expect it to drift down. This is over the first hour or so. After a day who knows?

When tracking pH drift of this sort one needs to be really A.R. with respect to his measurement practices. Calibrate, measure, check calibration, recalibrate (if necessary)...

 

[ajdelange]

LOL, I was wrong in any case. Sounds like maybe we're both more used to dealing in mol.

I am a big exponent for the use of mEq. It makes calculation so much easier (that's why they came up with it). Thus this flub is particularly embarrassing.

If it makes you feel any better, mash pH doesn't seem to have a discernable sensory effect on the finished beer, or at least in the beers evaluated by the brulosphy folks.
http://brulosophy.com/2017/07/24/wa...e-impact-of-high-mash-ph-exbeeriment-results/
http://brulosophy.com/2017/01/30/wa...he-impact-of-low-mash-ph-exbeeriment-results/

It makes a profound difference. The difference between good and really good beer. The best way I've seen it put was by someone who noted that "All the flavors just seem brighter" after he started getting mash pH into the right range. The fact that the Brulosophy experiments were unable to detect this is a reflection more on their technique than on whether controlled mash pH is beneficial. Everyone, more or less, knows that it is and that's why people struggle to control it.

The various mineral levels however do seem to play a more prominent role:
Sulfate to chloride ratio seems to be the most important stylistic target related to water chemistry.

Not so. See the sticky on that subject.

Sodium is detectable and has some kind of effect.

As do sulfate, chloride, potassium, iron etc. All indepedent to some extent. Chloride and sulfate may not represent 2 degrees of freedom but they represent almost 2.

Removing alkalinity from sparge water is important, especially for fly sparging.

For any kind of sparging as it will pull the pH of the wort up of it is not removed. Now if the mash was done at proper pH you will have obtained the benefits of that as the yeast can pretty much set the wort pH where they want it but do we want the yeast using up extract to generate acid or to generate beer?

Considering how much I've seen mash pH shift in a matter of 40 minutes, I'm not surprised to see you getting different measurements at different times. Personally I don't stress out about it since learning its effect may be negligible, especially if I'm in the right ballpark.

Once you are in the "brighter flavors" band it isn't necessary to control to 0.1 pH or better.

 

[Silver_Is_Money]

Even if you had initially presumed that your fresh and unopened CaCl2 prills were in the dihydrate form (which they will eventually be, once the package has been opened a few times) your Ca++ would only be about 67 ppm. In the overall picture of the multiple variabilities being juggled, this is hardly likely to be of significant concern, and many would consider 67 ppm Ca++ to be rather ideal.

Unless you tested them, the "presumption" of anhydrous was merely that. More likely they were somewhere between anhydrous and the dihydrate state. As stated in the previous thread, I've measured fresh and unopened packages at about 94% CaCl2 and 6% water.

You can leave some CaCl2 sitting on a scale and watch the weight increase over time.

 

[ajdelange]

Two comments:
First, the CaCl2 packages that I have tested showed low 90's as the percentage of CaCl2
Second: CaCl2 does not stop taking up water when the dihydrate state is reached. An old jar, which had always been sealed as soon as material was removed, came in at something like 65% IIRC. Leave CaCl2 exposed to moist air long enough and you will find a puddle of liquid where the powder was.

 

[Silver_Is_Money]

Two comments:
First, the CaCl2 packages that I have tested showed low 90's as the percentage of CaCl2
Second: CaCl2 does not stop taking up water when the dihydrate state is reached. An old jar, which had always been sealed as soon as material was removed, came in at something like 65% IIRC. Leave CaCl2 exposed to moist air long enough and you will find a puddle of liquid where the powder was.

I left a half pail of ice-melt CaCl2 sitting in my garage one summer, and it did exactly this. I tossed out a watery slush of CaCl2 that summer.

 

[dmcmillen]

As do sulfate, chloride, potassium, iron etc. All indepedent to some extent. Chloride and sulfate may not represent 2 degrees of freedom but they represent almost 2.

What do you mean by 2 degrees of freedom? How much should I be concerned with sulfate and chloride levels and the Sulfate to Chloride ratio? Much of what I read says that the ratio affects taste perception from very malty to very bitter. Is it really that important/perceivable? In the case of this porter, I would have to add some gypsum or epsom salt to get the sulfate level up in order to hit a desirable ratio. Trying to understand what is important and what isn't.

Through this process of understanding the water chemistry and how it affects my brews I have learned that it is not an exact science and I cannot completely rely on any of the spreadsheets (they do seem to provide a fairly good predictor of mineral levels), but can only effectively rely on performing test mashes using a spreadsheet as a guideline. That requires me to have at least a basic understanding of the chemistry in order to be able to make adjustments to get what I would like to achieve. At this point, although I have been brewing for a long time, I have almost no useful experience in developing enough data points to understand what levels of which minerals will provide what my palate enjoys. And with mineral levels, there is a lot of conflicting information out there (possibly because of a lot of varying palates). What I do know from cooking is that pH has a pronounced effect on taste perception, so I would think that pH level would have precedence over mineral levels. To date, this two grain porter will be my fourth brew trying to control the water chemistry. The reason I haven't learned anything useful (well not completely true, of course) is that it's taken the first three brews to understand that a spreadsheet is not a predictor of an exact science (these are not linear models), that I shouldn't try to match specific profiles provided in some of the spreadsheets, and unfortunately, and I'm embarrassed to say that it's taken this long to learn how to correctly take a reading with my MW102 and that learning is thanks to AJ. (manual states that reading is stable when hour glass goes off, which I was recording even though it continued to change and was not yet stable).

At this point I am reminded of the old saying “Good judgment comes from experience and a lotta that comes from bad judgment” Here we can substitute assumptions for judgement.

Software that I'm aware of (in addition to my own) that is capable of accepting directly measured DI_pH value inputs from the user includes Brewer's Friend, Low O2 Brewing, and EZ Water. For the latter, most do not understand that it is possible to input your own DI_mash pH values and override the defaults, as this is not really made clear or intuitive within the software itself.

Is is useful (i.e., how much do we gain) to measure DIpH for each grain that we are going to use and if so at what mash temp? In other words, if I were using the Brown grain in this recipe I would measure the DIpH at the 150 mash temp. What if I had another recipe with mash temp of 156. I suppose I'm asking how significant mash temp is in the DIpH?

 

[RPh_Guy]

@ajdelange
You could be right about mash pH. I'll continue to try to get it in range simply because it is widely regarded as a best practice.

I read your sticky on sulfate to chloride ratio, and I've also seen
http://brulosophy.com/2017/05/01/wa...d-when-ratio-is-the-same-exbeeriment-results/
When looking at a water profile I'm most likely to consider the ratio rather than the individuals levels (based on what little I know), but I would also consider the mineral load if the levels are particularly low or high. From a strictly scientific standpoint your argument is valid that these ion levels represent two degrees of freedom, but that doesn't change the tendency for the ratio to be a deterministic factor in the perception of the beer, in the context of most people's brewing water.
Using ONLY the ratio is an oversimplification and may be inappropriate in some odd situations. I think we agree on that.

We're on the same page with regard to sparge water I was just saying the effect of too much alkalinity might be amplified if fly sparging... for the same reason fly sparging can yield better extraction.

@dmcmillen
FWIW anecdotally I notice a huge difference in my palate when adding chloride, but my water also has a substantial amount of sulfate. You could adjust levels after brewing the beer on small samples as a taste trial.

One degree of freedom: The ratio is all that matters.
Two degrees of freedom: The individual levels have fully independent effects.
The truth is probably somewhere in the middle.

 

[ajdelange]

What do you mean by 2 degrees of freedom?

It means that the effect of the concentration of chloride on the flavor of the beer is completely independent of the concentration of sulfate and conversely.

How much should I be concerned with sulfate and chloride levels and the Sulfate to Chloride ratio?

You should be quite concerned as each has a noticeable effect on the way the beer tastes. The problem is that peoples' preferences vary. Some don't like sulfate at all. Some prefer more than the EPA's SMCL. Some like the sweetening effect of chloride. Some find it cloying. You will have to determine what you and your customers prefer by experimenting.

Much of what I read says that the ratio affects taste perception from very malty to very bitter. Is it really that important/perceivable?

This notion implies that there is only one degree of freedom i.e. the ratio. That beer with 10 mg/L calcium and 10 mg/L chloride will be the same as one with 500 mg/L of each.

In the case of this porter, I would have to add some gypsum or epsom salt to get the sulfate level up in order to hit a desirable ratio. Trying to understand what is important and what isn't.

Many a brewer has gone down that path. It is best, IMO, to start with minimal chloride and very low or no sulfate at all and then incrementally add sulfate to see if you like it at all and if you do at what level. See the Sticky on Cl/SO4 ratio.

Through this process of understanding the water chemistry and how it affects my brews I have learned that it is not an exact science ...

The science is exact but applying it correctly is an art.

...and I cannot completely rely on any of the spreadsheets (they do seem to provide a fairly good predictor of mineral levels), but can only effectively rely on performing test mashes using a spreadsheet as a guideline.

Many of the spreadsheet authors do not understand the science and some that do refuse to apply it properly for various reasons. Those that do and want to apply it properly are limited by the fact that this requires laborious measurements on the individual mash components (malts, water).

That requires me to have at least a basic understanding of the chemistry in order to be able to make adjustments to get what I would like to achieve.

Yes it does - a point that few understand. Even fewer are willing to undertake the necessary study. At the same time remember that lots of good beer was made in breweries whose owners refused to have those new-fangled hydrometers in their plants. They eventually, over hundreds of brews, stumbled onto workable recipes and procedures.

At this point, although I have been brewing for a long time, I have almost no useful experience in developing enough data points to understand what levels of which minerals will provide what my palate enjoys.

. Experience will give you that.

And with mineral levels, there is a lot of conflicting information out there (possibly because of a lot of varying palates).

That's definitely a part of it IMO.

What I do know from cooking is that pH has a pronounced effect on taste perception, so I would think that pH level would have precedence over mineral levels.

It does, IMO. But then I operate in the less is more domain when it comes to mineral additions.

At this point I am reminded of the old saying “Good judgment comes from experience and a lotta that comes from bad judgment” Here we can substitute assumptions for judgement.

I've seen it put slightly differently: That wisdom is the state we come to by having experiences we wouldn't have had had we been wise.

Is is useful (i.e., how much do we gain) to measure DIpH for each grain that we are going to use and if so at what mash temp?

It is useful but is it necessary? I've done quite well by measuring the malts I use most as base malts and then using Kai Troester's data for the whole host of specialty malts he measured. Even though those were pioneering measurements and the technique was not that robust the data are at least partially valid and as the specialties are used in small proportion relative to the base malts this doesn't seem to cause much error.

In other words, if I were using the Brown grain in this recipe I would measure the DIpH at the 150 mash temp.

The system falls apart when a renegade grain like this Brown is encountered. It apparently has buffering 3 times what is typical for other grains.

What if I had another recipe with mash temp of 156. I suppose I'm asking how significant mash temp is in the DIpH?

We all know that the pH of mash changes with temperature. When making a complete measurement on a malt one meaures what I call its "glide", that is, the amount of change in DI pH vs. temperature. Since the model for a malt's protein deficit at a given pH is just a Taylor series expansion about the DI mash pH it is a simple matter to compute the deficit at any mash temperature from the model derived from measurements at another temperature.

 

[ajdelange]

From a strictly scientific standpoint your argument is valid that these ion levels represent two degrees of freedom, but that doesn't change the tendency for the ratio to be a deterministic factor in the perception of the beer, in the context of most people's brewing water.

Keep in mind that the ratio and the concentration of one ion or the other represents 2 degrees of freedom.

Using ONLY the ratio is an oversimplification and may be inappropriate in some odd situations. I think we agree on that.

It is an oversimplification because there is more than one degree of freedom here. Some argue that the ratio alone suffices if x < Cl < y (or for some range of sulfate) but that is, of course, simply a demonstration that there is more than 1 DOF. Ratio alone is, thus, inappropriate in any case as one must make some statement about either the sulfate or chloride.

 

[RPh_Guy]

Thank you for your advice AJ!
I don't think my interpretation is too far off the mark from the conclusions you've drawn, just maybe a little different perspective.
Chemistry is fun. Beer is good.

Is it true I can bake my "anhydrous" calcium cloride to remove some of the water? Or would it be better just to make a bulk solution with distilled water? Would the solution have a reasonable shelf life?

 

[ajdelange]

I don't think my interpretation is too far off the mark from the conclusions you've drawn,

I don't either. Is there more than one degree of freedom? Absolutely! Are chloride and sulfate completely independent (implying 2)? I'm not so sure about that.

Is it true I can bake my "anhydrous" calcium cloride to remove some of the water?

Yes. I think you have to get it over 240 or so °F to get all the water though and you have to cool it in a dessicator or it will pick up water before you get it into a sealed container.

Or would it be better just to make a bulk solution with distilled water? Would the solution have a reasonable shelf life?

I think that's going to be the easier route and there is reduced danger of moisture pick up during measuring if you work with the liquid. The liquid can exchange moisture with the air depending on strength of the solution and humidity but not nearly at the rate the solid does. Do keep it in a sealed container, though. Its shelf life should be long but CaCl2 is cheap enough that any not used can be discarded and a fresh solution made up each time.

Some have reported seeing white flakes in CaCl2 solutions. This is doubtless CaCO3 produced when CO2 from the air react with the Ca++ ions. There's going to be some HCO3- ion in a solution that shows these flakes too so you might want to make appearance of those flakes your indication that a fresh solution should be made.

 

[Silver_Is_Money]

Is is useful (i.e., how much do we gain) to measure DIpH for each grain that we are going to use and if so at what mash temp? In other words, if I were using the Brown grain in this recipe I would measure the DIpH at the 150 mash temp. What if I had another recipe with mash temp of 156. I suppose I'm asking how significant mash temp is in the DIpH?

You are free to perform repeated series of DI_mash pH tests, first at 150 degrees, and then again at 156 degrees (with all else being equal) to see if there is measurable correlation, and we all stand to learn from this experimentation, but if there was any significant extant expectation of correlation with respect to nominal mash temperature and the release of malt/grain acidity then software designed to predict mash pH would be designed to ask for mash temperature as a requisite input value, and no such software that I'm aware of asks for this input.

 

[ajdelange]

The model for the 'acidity' of a malt involves 4 parameters, a, b, c, pHdi and glide (the rate of change of pHdi with temperature). The acidity is

mEq/kg•pH = a*(pH - pHdi) + b*(pH - pHdi)^2 + c*(pH - pHdi)^3

Often only a is given as, with base malts at least, mash pH is close to pHdi

pHdi is the pH at which you want to know the acidity. We are aware that measured pH is a function of temperature. Because of the complexities it would introduce if we tried to work at mash temperature (is that dough in, beta glucan rest, protein rest or saccharification rest?) we calculate at room temperature because we know that if the pH is correct at room temperature we will get good beer. But the data which led to the determination of a, b, and c are logically collected at higher temperature as we want the acidity produced in the test to be representative of what happens in the mash tun. Thus the pHdi measured during the test is not the pHdi we would see if we worked at room temperature. This is one of the advantages of the Taylor series model. If we know how pHdi changes with temperature,the glide, we can easily calculate the acidity referenced to room temperature measurement simply by plugging in the room temperature pHdi for each malt, rather than the measured mash temperature pHdi. This is what I would want the maltsters to do if they ever got on board with this system, that is, specify a, b, c and pHdi for each malt they sell. Or, probably better yet, just put pHdi and the amount of acid required to got 0.1 pH below that, 0.3 pH below that etc (for a base malt) IOW the actual titratable acidity of their products.

The spreadsheet I use lists a, b, c, pHdi at measurement temperature, measurement temperature and glide. When a calculation is done the user inputs the temperature at which he wishes to estimate mash pH so there is software that asks for temperature information but I wouldn't recommend doing that in software for public consumption. Just storing a, b, c and room temperature pHdi should suffice.

 

[dmcmillen]

The science is exact but applying it correctly is an art.

"The science is exact but my understanding is inexact" What makes the science feel inexact is that these are for the most part not linear models.

That wisdom is the state we come to by having experiences we wouldn't have had had we been wise.

Boy, I should be a really wise man!

Many a brewer has gone down that path. It is best, IMO, to start with minimal chloride and very low or no sulfate at all and then incrementally add sulfate to see if you like it at all and if you do at what level. See the Sticky on Cl/SO4 ratio.

I started out with this recipe trying to match your recommendation of 1 teaspoon of CaCl for which I used 3.6g. That happened to add 41ppm Ca and 73ppm Cl giving me 50ppm Ca (50 Ca was also Silver's suggestion) and 77ppm Cl. My water has only 9ppm sulfate making the ratio about .1. I could just as easily shoot for 25ppm Ca which would lower the Cl accordingly. Not sure what "minimal" Cl is. I see ranges of 0-250 and 10-100. I think based on your recommendation here, I will not make any additional additions and see what I get.

I have two additional questions:

At what point during the mash should I consider the pH stable enough to calculate any additions if necessary and when should I make those additions? I am assuming that it would make sense to only add half the calculation and then test again. I always understood that the majority of the mash reactions are complete in about 30 mins, which I assume is why the test mash reading is taken at 20 min.

I have a 3 keggle, 2 pump gas heat system and the mash tun has .7 gal under the false bottom. Although I stir the mash regularly, I only recirc the mash if I have to add heat which means that samples taken typically do not have the .7 gal mixed into the total mash water which for a 5 gal batch is as much as 20%. Does that affect the readings? Is it necessary to recirc before taking a reading?

 

[Silver_Is_Money]

It is not generally the best plan to attempt to make pH modification additions during the mash, though many will do so. The conversion is essentially over (or very close to over) at about the 20 minute mark, so pH changes made beyond that point will have little to no impact upon enzymatic activity. The best plan is to make all additions related to mash pH modification up front in the strike water, then record the 20 minute mash pH and use the data to glean what changes may need to be made for the next batch which repeats the recipe identically.

 

[dmcmillen]

I would like to get some thoughts on my last question above on the mash water volume below the false bottom.

 

[Silver_Is_Money]

I would like to get some thoughts on my last question above on the mash water volume below the false bottom.

If the 0.7 gallons below the false bottom are part of the initial measure of your strike water, then in my opinion your occasional mash stirring will be sufficient. If these 0.7 gallons were not initially factored into your strike water volume, then their 98 ppm of alkalinity has not been properly addressed, and that would throw things off.

 

[dmcmillen]

If these 0.7 gallons were not initially factored into your strike water volume, then their 98 ppm of alkalinity has not been properly addressed, and that would throw things off.

The .7 gals is considered in the strike water volume. The mash stirring only stirs the mash water above the false bottom unless I recirc with the pump when adding heat or at the end of the mash when I do a mash out. I usually shoot for a a mash thickness of 1.5 gts/lb so that the mash above the false bottom is not too thick and I always hit my numbers.

 

[Silver_Is_Money]

The .7 gals is considered in the strike water volume. The mash stirring only stirs the mash water above the false bottom unless I recirc with the pump when adding heat or at the end of the mash when I do a mash out. I usually shoot for a a mash thickness of 1.5 gts/lb so that the mash above the false bottom is not too thick and I always hit my numbers.

Since I mash in a cooler conversion, I must defer to others with more experience with your equipment for their opinions on this matter.