Magnesium vs Calcium in brewing water question

[chrisgg]

I've mentioned this multiple times already of late, but if our interpretation of Kolbach as to the influence of calcium and magnesium has been grossly incorrect and overstated then our interpretation of RA (Residual Alkalinity) is also grossly incorrect. And if (as per Barth and Zaman) calcium's impact upon downward pH shift within the mash is vastly different for each malt within a grist, then RA becomes essentially a contrived figment of our imagination.

Kolbach stated this:
mEq/L RA = mEq/L Alkalinity - [(mEq/L Ca)/3.5 + (mEq/L Mg)/7]

Barth and Zaman only looked at calcium, but they looked at its impact during the mash as opposed to knockout, and whereas for the case of knockout Kolbach established '3.5' as the divisor for calcium (meaning that for every 3.5 mEq's of calcium 1 mEq of Alkalinity is consumed) Barth and Zaman found that for their specific lots of the three malts they tested the divisor was as follows within the mash:

Pilsner malt divisor = 14.8 (vs. 3.5)
Pale Ale malt divisor = 7.2 (vs. 3.5)
Munich malt divisor = 12.2 (vs. 3.5)

Where I find potential flaw in Barth and Zaman is that they measured only 5 minutes into the mash whereby to establish these divisors. I think they should have tested at 30, 45, and 60 minutes into the mash. And I suspect the divisors would have diminished measurably thereby, albeit not all the way to 3.5. I suspect that they did not allow for sufficient time for the added calcium ions within the mash water to permeate into the confines of the crushed malts whereby to release H+ ions.

Very interesting that you believe the effect of calcium on lowering the pH of the mash to be a lot less than previously thought by Kolbach. There are a good number of calculators out there that still use his magic 3.5 divisor.
Could you say what you think is the best way to deal with pH control in the mash? Do you have a preferred way of dealing with alkalinity? How about pre-boiling the water to remove carbonates or adding acids like AMS or lactic...or maybe just adjusting the grain bill? Or maybe using distilled water and adding the minerals that are needed, if any?

 

[Silver_Is_Money]

Very interesting that you believe the effect of calcium on lowering the pH of the mash to be a lot less than previously thought by Kolbach. There are a good number of calculators out there that still use his magic 3.5 divisor.
Could you say what you think is the best way to deal with pH control in the mash? Do you have a preferred way of dealing with alkalinity? How about pre-boiling the water to remove carbonates or adding acids like AMS or lactic...or maybe just adjusting the grain bill? Or maybe using distilled water and adding the minerals that are needed, if any?

I learned it, I did not do testing of my own by which to verify it. Multiple years ago AJ deLange was already openly hinting on this very forum that the pH reducing effect of calcium is likely to be only about 50% of what had previously been presumed. And nearly 4 years ago now an early beta tester of MME whom I highly respect (and who is free to reveal himself if so desired) and who frequents this forum with well respected posts told me that in his testing he verified AJ's contention, as for him it proved to also be in the vicinity of 50% or less of what Kolbach indicates, thus inspiring me to incorporate an adjustability feature into MME for this well before I became aware of the peer reviewed hard science undertaken by Barth and Zaman. So Barth and Zaman are not alone in this, and may not even be the first to be given credit. But certainly I deserve zero credit. My calculator defaults to 3.5 upon download, but then allows for the factor to be easily re-set.

I agree that mineralization plays an important part, but for pH control I rely upon acidification (mainly via lactic acid) or the addition of baking soda. I'm presently about to experiment with citric acid to try something a bit different. But here I'm also not an early experimenter. For the least impact upon flavor phosphoric acid is best. I can't buy AMS/CRS in the USA.

I make up mineralized water from good quality RO, which routinely tests at under 7 ppm via a TDS meter.

 

[chrisgg]

I learned it, I did not do testing of my own by which to verify it. Multiple years ago AJ deLange was already openly hinting on this very forum that the pH reducing effect of calcium is likely to be only about 50% of what had previously been presumed. And nearly 4 years ago now an early beta tester of MME whom I highly respect (and who is free to reveal himself if so desired) and who frequents this forum with well respected posts told me that in his testing he verified AJ's contention, as for him it proved to also be in the vicinity of 50% or less of what Kolbach indicates, thus inspiring me to incorporate an adjustability feature into MME for this well before I became aware of the peer reviewed hard science undertaken by Barth and Zaman. So Barth and Zaman are not alone in this, and may not even be the first to be given credit. But certainly I deserve zero credit. My calculator defaults to 3.5 upon download, but then allows for the factor to be easily re-set.

I agree that mineralization plays an important part, but for pH control I rely upon acidification (mainly via lactic acid) or the addition of baking soda. I'm presently about to experiment with citric acid to try something a bit different. But here I'm also not an early experimenter. For the least impact upon flavor phosphoric acid is best. I can't buy AMS/CRS in the USA.

I make up mineralized water from good quality RO, which routinely tests at under 7 ppm via a TDS meter.

Thanks for all that information. I'll try out the various methods in my next few brews, see how the pH turns out and whether it changes anything for the better.

I only recently bought a pH meter a few weeks ago. Hence my sudden interest in the subject. Years ago I started adding gypsum to the mash, not consciously to bring down pH, but to emulate the high quantities in Burton water, wondering if it might improve my beer. I thought it did taste a bit better but not really sure. I originally boiled my water to precipitate CaCO3 for my first few brews, as written in various home brewing books, but found it very tedious and time consuming. When I left out the boil I didn't notice any difference in my sugar extract from the grain or in the final taste of the beer, despite high bicarbonate levels of 305 ppm, Ca 121 ppm and relatively low permanent hardness levels (sulphate 21 ppm and chloride 27 ppm). So l left out the boil and have never reinstated it since.
Now that I have a pH meter I checked the pH in my last brew mash (in cooled mash) and found it to be 5.9 which seems a bit high, with optimal regarded as 5.4. That was after adding the usual 10g of gypsum to the 9 litre mash. So now I'm looking again at ways of bringing down the pH. I certainly don't want to add even more gypsum.

 

[mabrungard]

I learned it, I did not do testing of my own by which to verify it. Multiple years ago AJ deLange was already openly hinting on this very forum that the pH reducing effect of calcium is likely to be only about 50% of what had previously been presumed.

I can attest through my volumes of mashing pH testing and verification, that Kolbach's original results are quite valid and accurate. There is NO reduction of the pH lowering effects of calcium or magnesium in the mashing environment. Both Larry and AJ are very wrong on this point.

 

[InspectorJon]

 

[Silver_Is_Money]

I can attest through my volumes of mashing pH testing and verification, that Kolbach's original results are quite valid and accurate. There is NO reduction of the pH lowering effects of calcium or magnesium in the mashing environment. Both Larry and AJ are very wrong on this point.

Also incorrect must therefore be research chemists Barth and Zaman. Have you read their research paper?

 

[Silver_Is_Money]

Very interesting that you believe the effect of calcium on lowering the pH of the mash to be a lot less than previously thought by Kolbach. There are a good number of calculators out there that still use his magic 3.5 divisor.

Although this will indeed sound cliche, and particularly more so in this present era where being urged to follow the science is akin to being asked to follow the bouncing ball, but it's not so much that I "believe it" (which would require testing that I have not personally undertaken) as rather that I'm just trying to "follow the science" of those I trust and who have done the testing. As stated, MME ships defaulted to the Kolbach 3.5 divisor for calcium, and this leaves the capability to alter it fully up to the preference and observations of the end user. MME may be unique in offering this ability to openly alter internal defaults, and offers this and many other avenues for easy and fully optional default alterations right on the main screen.

 

[chrisgg]

Although this will indeed sound cliche, and particularly more so in this present era where being urged to follow the science is akin to being asked to follow the bouncing ball, but it's not so much that I "believe it" (which would require testing that I have not personally undertaken) as rather that I'm just trying to "follow the science" of those I trust and who have done the testing. As stated, MME ships defaulted to the Kolbach 3.5 divisor for calcium, and this leaves the capability to alter it fully up to the preference and observations of the end user. MME may be unique in offering this ability to openly alter internal defaults, and offers this and many other avenues for easy and fully optional default alterations right on the main screen.

A minor point on the MME spreadsheet. Very good on the whole, but is there any way of widening the columns, as some are too narrow to fit in the data or words properly. I can't seem to edit the column width. Also, I can't see an option of boiling the water to reduce bicarbonate, which may be my preferred option to adding acid or obtaining RO water..

 

[Silver_Is_Money]

A minor point on the MME spreadsheet. Very good on the whole, but is there any way of widening the columns, as some are too narrow to fit in the data or words properly. I can't seem to edit the column width. Also, I can't see an option of boiling the water to reduce bicarbonate, which may be my preferred option to adding acid or obtaining RO water..

A) What spreadsheet are you using? If it is Libreoffice (in Linux, and I presume also in Windows) it generally comes down to not having the required font package installed. I've fixed this a few times simply by installing the following:

1) fonts-croscore
2) fonts-dejavu
3) fonts-dejavu-core
4) fonts-dejavu-extra

Check and add any of the above which are missing in your operating system. Then re-launch LibreOffice and see if the font size problem vanishes. I believe it most likely comes down to not having #1 or #4 installed, with particular emphasis upon #4, but check for all of them and install those not presently installed. What you need is the condensed fonts set, and I believe this is part of the 'extra' fonts package. This font set (from Bitstream) is likely also available for use by Windows Excel.

B) You are correct in that there is no water boiling carbonate reduction module. If you tell me your waters ppm calcium and ppm alkalinity as CaCO3 (or alternately, its bicarbonate) I can tell you (within reasonable precision) what your post boil alkalinity and calcium mg/L (ppm) expectations should be. This will not change, and will become your baseline analyticals for your source water.

 

[chrisgg]

A) What spreadsheet are you using? If it is Libreoffice (in Linux, and I presume also in Windows) it generally comes down to not having the required font package installed. I've fixed this a few times simply by installing the following:

1) fonts-croscore
2) fonts-dejavu
3) fonts-dejavu-core
4) fonts-dejavu-extra

Check and add any of the above which are missing in your operating system. Then re-launch LibreOffice and see if the font size problem vanishes. I believe it most likely comes down to not having #1 or #4 installed, with particular emphasis upon #4, but check for all of them and install those not presently installed. What you need is the condensed fonts set, and I believe this is part of the 'extra' fonts package. This font set (from Bitstream) is likely also available for use by Windows Excel.

B) You are correct in that there is no water boiling carbonate reduction module. If you tell me your waters ppm calcium and ppm alkalinity as CaCO3 (or alternately, its bicarbonate) I can tell you (within reasonable precision) what your post boil alkalinity and calcium mg/L (ppm) expectations should be. This will not change, and will become your baseline analyticals for your source water.

My fault...I can simply enlarge the view to solve the column width problem and make the print easier to read, such as the types of malt addition drop-down list which is miniscule in the default size. It's a MashRite LLC 11/17/2020 spreadsheet by the way. If I boil beforehand, I can calculate the HCO3 and calcium myself after boiling, by using Martins Bru'n Water formula and then enter that as the original brew water before any additions. That's great...I'm OK with the spreadsheet now, thanks.

 

[Silver_Is_Money]

You may still receive benefit from installing the condensed dejavu font set.