Calcium and Magnesium in the Mash Tun

[PeeBee]

As part of my "inspection" of water chemistry and the Mash, I came around to Calcium and Magnesium ions. I'm glued to this "inspection" because I was so sure this modern day fascination with water was so much nonsense. What I found was: Most is utter nonsense! But it was built on a subject that made utter nonsense of what I'd been doing for years (decades!).

So, stuck with a string of mashes coming out with a pH as low as 4.9 I decided I need to look at this "water" caper more closely. The infamous "Defuddler" spreadsheet is a product of that (download link in signature below), as is my distaste for anything that mentions water "Hardness" (it's out-dated knowledge that will worm its way into your head and screw up any dreams of coming to terms with water for brewing). But I'm still getting mash pHs below 5.0. I've got to give the "Defuddler" a bit more time to collect more data, but I already know it isn't the complete solution.

So, my attention is drawn to "Calcium" (and Magnesium, but it isn't claimed to be as influential as Calcium). This is really (in modern terms) the extent of "Hardness". Other Cations (like Iron) can be drawn into the same category, but is rare in water fit (and treated) for drinking, so just Calcium and Magnesium is worthy of study.


So, I'd already read Calcium would reduce the pH of a Mash, but I'd never appreciated by how much! It's a lot! Not helped by Murphy & Son putting out misleading stuff like "However, their <Ca and Mg that is> impact on the alkalinity of water in relation to brewing beer is marginal, if at all" … which isn't wrong, but it depends on how you read it! BTW, Anions like HCO3 have nothing to do with "Hardness" but you won't have that fact suggested by many articles ("CO3" and "HCO3" is covered by "Alkalinity", not "Hardness") and most people think "Hardness" is "carbonate" (it isn't!).

The solution is easy: Put Calcium and Magnesium salts in the sparge water, or boiler directly, not the Mash. We can do that simply, whereas it might cause problems for commercial breweries to organise. Removing Calcium and Magnesium additions from the mash is even an option for "Bru'n Water" users ("Add Hardness Minerals to Kettle?" in "Water Adjustment" page), and the effect is miraculous.

Can anyone see an issue with this?


[EDIT: To remove my favourite involuntary trick: Mix anions and cations up].


If anyone reading this hasn't water containing <30ppm Calcium, or doesn't use bottled water or "RO" water for mashing, sorry, my babbling won't cover you just yet.

[Cobnut]

Just to be picky (pedantic):

Ca++ and Mg++ are cations and HCO3- and Cl- (etc.) are anions.

You have them the wrong way round.

[PeeBee]

Nothing picky or pedantic. It's just what I do so just put with it.

I did figure out why I did it a while back, but it obviously never cured me: Anodes are positive terminals which (in water) attract cations, not anions. Damn silly way of arranging it. So, even if I say I'm cured now, I'll do it again next week.

[EDIT: Hang-on … I'll edit it so I'm not confusing anyone … thanks!]


Anyway … back on subject (!) all this business of "holding back crystal and roast malts in the mash" really does make a BIG difference, Calcium really does mess about with mash pHs and it's not a trivial "secondary" effect at all. Just like numerous fellows have been trying to tell me in the past (and I failed to listen). So wait to you see what I'll do with that! I reckon I can make my "Defuddler" a side show to all the water capering I'm going to explore. The "Water Pro[pH]iler" cometh (Ha, ha, ha!)

[PeeBee]

... The solution is easy: Put Calcium and Magnesium salts in the sparge water, or boiler directly, not the Mash. ...

Weeeelllllll .... not that easy! I get the impression you shouldn't leave the mash devoid of all Calcium (I find references to Calcium being important to the action of enzymes, alpha-amylase being noted especially), but having it below 50mg/L in the mash shouldn't be a problem.

"Alkalinity" does need sorting out for the mash, it's a vital component of the mash (where it's dictating the pH outcome).

This water calculator project I'm embarking on starts with a bit of a lie. "Water Pro[pH]iler" I've nicknamed it, but "pH" predicting is the last thing I want to do. Maneuvering the components of the water so pH will fall into a desired range is on the cards, but not precise prediction. I'll not be chasing pH to values measured to two decimal places because 1: It's not possible, 2: The instruments most own are not capable of reading such accuracy, and, most importantly, 3: It's not necessary. I originally had the intention of calculating stuff like "pH-DI" (the pH of a known amount of malt in a known amount of distilled water), but the measurements are quite difficult to maintain ... not only will they change between different manufacturers, but the value change between different batches from the same manufacturer!


pH prediction is fantastically complicated! It's not a matter of; the water contains these ions, so the Mash pH will be THIS. The translation of specific ions to the, fairly woolie, "pH", is fiendishly complicated! Involves the outcomes of interactions with buffering. Well beyond most of our intellects (I don't think I'll bother to test mine). The pharting about with "residual alkalinity" is one vain attempt to make the translation easy; it involves misusing Kolbach's work on "residual alkalinity" from the 1950s. If using it gives you a warm fuzzy feeling, or lines your pockets with cash extracted from the gullible you preach to, go ahead and use it, I can't imagine the results will be far enough off to make significant differences (I can't accept being lied to so gave up with the subject of "RA").


So, the design parameters for this "Water Pro[pH]iler": (The square brackets around "pH" by-the-way, are to break up the ghostly appearance of an undesirable name from history!):

I quite like John Palmer's "cube".

Beer Cube.jpg (43.72 KiB) Viewed 464 times

There's potential there to have a very graphically "visual" water profile designer instead of pouring over lots of overly precise numbers. The "RA" garbage will have to go, of course, but Alkalinity can still make up an axis, paired with beer colour as there will be a tentative link. Sulphate, Chloride, and Beer Flavour can make up another axis, although there will need to be careful about "ratio" as that carries some strong dissension. And finally "Beer Structure" (Calcium content); there's some confusion about this term too, but it nicely brackets "British" traditional beers which often have a high Calcium content ... Mr Palmer claims he only knows two beers with a "firm" "structure", listing one as "Burton Ale" but that's a rather wide description; most British traditional beer fits in the 100+mg/L "Calcium" bracket anyhow.

A "Cube" is un-necessary, the parameters lack the linking for display on a true "three axis" graph, but two axis, and a third "dissociated" axis does the trick.

Chris Colby outlines an interesting approach to water profile building. His blog (beerandgardeningjournal.com) isn't available at this moment, but I can dig up his posts (and have his book Methods of Modern Homebrewing: The Comprehensive Guide to Contemporary Craft Beer Brewing). No pH predicting, No nonsense, even the mention of teaspoons. Some difficult to follow bits but they can be sorted. Should make a fine basis?

But, whatever I come up with, it is to remain extensible and not tied in to any one idea.

I'll use "Bru'n Water" to dig up ideas and help test outcomes. So ... I'll get to it.

[PeeBee]

Ah, wow! I found this while nosing about today. I'll title it "Why I have nothing to do with pH prediction":

Why I have nothing to do with pH prediction

[PeeBee]

This redirection in the thread makes the thread's title somewhat cryptic ... I'll open a new thread to cover the creation of this "Water Pro[pH]iler" ... Creating a Brewing Water Calculator - the "Water Pro[pH]iler"