What is Residual Alkalinity?

[peebee]

... It looks, if you want to build something to calculate your minerals, that this four part series is a simpler way to start with. It is already more or less algorithmic in nature.

I found the four articles, all from June 2016:
Brewing Liquor for Pale Beers (0–10 SRM)
Brewing Liquor for Amber Beers (10–20 SRM)
Brewing Liquor for Brown Beers (20–30 SRM)
Brewing Liquor for Dark Beers (30–40 SRM)
I'll flick through them later. Thanks.

I don't really want "a simpler way": I've already done a hatchet job on "RA" and pared its imitations down to its bare bones (how Paul Kolbach saw it seventy years ago? "RA"="Alkalinity"-"Ca++"/3.5-"Mg++"/7 *** ... everything measured as milliequivalents per litre; for which I spouted a summarised explanation which I'll probably tidy before I'm done, if I even need to?). The three-axis graph I did should make a basis for a very visual output covering any beer, be it the lightest of third world "lager" or darkest "Real Ale" Stout. Because I don't want another "water calculator" where you copy well water from some location or other, or, add a bit here, a bit there, and make sure it all balances. I want a pictural driven calculator that will cover everything (beery that is!). A month ago, I'd have said to anyone suggesting such a thing to not be so daft. I'm not so sure now.

This seems such an obvious thing to do ... has anyone actually done it (would save me the effort). Or have I disengaged my imagination from anything resembling reality ... I'm really good at that!


*** All "RA" is, is a judgment of how much "Alkalinity" remains after some is consumed by malt phosphates reacting with water-borne Calcium and Magnesium ions.

Anyone got a better summary?

The equation can also be written "RA"="Alkalinity"-(("Ca++"+"Mg++"/2)/3.5) but I don't think that looks as neat (all of them brackets ... ugh).

Seems the amount of "Alkalinity" consumed depends on the water concentration (mg per litre) of Ca/Mg ions, not the total number of the ions in the mash? Or the total number of malt phosphates in the mash? i.e. The amount of malt and the ratio of water mixed with it is immaterial?

 

[chthon]

*** All "RA" is, is a judgment of how much "Alkalinity" remains after some is consumed by malt phosphates reacting with water-borne Calcium and Magnesium ions.

Anyone got a better summary?

I think it is difficult to give a better summary than this.

How much do you know about weak acids and bases and chemical buffering? Because that is what residual alkalinity is all about. The reactions remove OH- ions from the mix (alkalinity lowers) and add H+ ions to the mix (acidity increases).

These phosphates are complex organic molecules. So what RA seems to imply is that it is a simplified result of complex interactions. The questions this raises for me are:

• "Residual" in reference to what?
• What is the relationship between RA and pH?

 

[Hazelwood Brewery]

*** All "RA" is, is a judgment of how much "Alkalinity" remains after some is consumed by malt phosphates reacting with water-borne Calcium and Magnesium ions.

Agreed. If you mash with distilled water your mash pH will tend toward 6 for pale malt and 5 (or even lower) for dark malt. A positive RA will tend to increase the pH of the mash above this level, a negative RA will tend to decrease the pH of the mash below this level. This is why RA has some practical value.

Seems the amount of "Alkalinity" consumed depends on the water concentration (mg per litre) of Ca/Mg ions, not the total number of the ions in the mash? Or the total number of malt phosphates in the mash? i.e. The amount of malt and the ratio of water mixed with it is immaterial?

I’m not sure about this statement, I think you might need to say milliequivalents per litre?

Your last statement “ratio of water” may be wrong, remember the Kolbach formula is for a given mash ratio and grist size.

 

[peebee]

"Residual" in reference to what?

Ha! That's one that's been bothering me. Because "Residual" is figured before the event (mash). "Residual Alkalinity" ... to be?

I’m not sure about this statement, I think you might need to say milliequivalents per litre?

Nope, I meant milligrams 'cos I'm talking about real ion concentration ... milliequivalents has switched over to a fantasy world. Like "as CaCO3" ... ah, okay, maybe not that much of a fantasy

 

[peebee]

Your last statement “ratio of water” may be wrong, remember the Kolbach formula is for a given mash ratio and grist size.

Yeah. I'd like to find that. I've only come across hints ... until you whacked it into me just now! But how does Holbach's equation hold up to different mash ratios and grist size?

 

[Hazelwood Brewery]

Yeah. I'd like to find that. I've only come across hints ... until you whacked it into me just now! But how does Holbach's equation hold up to different mash ratios and grist size?

I found a couple of tables in this book…

Mash ratio…

Grist…

Mash ratio seems to be fairly significant.

 

[Hazelwood Brewery]

Nope, I meant milligrams 'cos I'm talking about real ion concentration ... milliequivalents has switched over to a fantasy world. Like "as CaCO3" ... ah, okay, maybe not that much of a fantasy

OK, I’ll accept that as we’re not talking about a specific chemical reaction where chemical equivalence needs to be taken into account.

 

[peebee]

I found a couple of tables in this book…

Aww, cwap. I'm back to beginning hoping to figure out where that "3.5" in the RA formula comes from and how best to modify it for my own environment? I haven't had time to go over those tables yet, but "RA/pH·L" is a new one on me, and the inclusion of "pH" makes me very suspicious. I might need to trawl through some of Mr Troester's stuff?

What really annoys me, are those saying I'm wasting my time because someone with a degree who's written a book "obviously" knows far more than me and should be listened to without question. (No names; Mr "I-live-in-Australia" will do).

So "RA" is not-fit-for-purpose (as typically referred to) but hopefully I can find the necessary patches and get my "project" back on track again.

 

[foxy]

Aww, cwap. I'm back to beginning hoping to figure out where that "3.5" in the RA formula comes from and how best to modify it for my own environment? I haven't had time to go over those tables yet, but "RA/pH·L" is a new one on me, and the inclusion of "pH" makes me very suspicious. I might need to trawl through some of Mr Troester's stuff?

What really annoys me, are those saying I'm wasting my time because someone with a degree who's written a book "obviously" knows far more than me and should be listened to without question. (No names; Mr "I-live-in-Australia" will do).

So "RA" is not-fit-for-purpose (as typically referred to) but hopefully I can find the necessary patches and get my "project" back on track again.

Well if you listened to "I live in Australia" you would learn something about water instead of trying to confuse everyone about something so simple.

 

[peebee]

What is the relationship between RA and pH?

Think I've just answered that one?

"RA/pH·L" is a new one on me, and the inclusion of "pH" makes me very suspicious.

 

[peebee]

... confuse everyone about something so simple.

(Followed by John Palmer's video of one of his classroom talks).

"Something so simple" ... like in Mr Palmer's talk? ...

That was a poorly put together argument!


Unfortunately, Mr Palmer's talk didn't cover how Paul Holbach's "RA" equation holds up to different mash ratios and grist size. So, I'm none-the-wiser for watching it. Maybe it will turn out to not make a radical difference worth the extra calculation? But it's not for me to assume that. I might well be satisfied if Mr Palmer would say it?

Any way ... I doubt I'm confusing anyone in this discussion 'cos they won't have read this far. Only those with an interest in the validity of "RA" figures will be here. And my interest in "RA" is to develop a simple means of designing water additions (which doesn't mean the backroom work getting there will be simple!).

 

[Hazelwood Brewery]

Aww, cwap. I'm back to beginning hoping to figure out where that "3.5" in the RA formula comes from and how best to modify it for my own environment? I haven't had time to go over those tables yet, but "RA/pH·L" is a new one on me, and the inclusion of "pH" makes me very suspicious. I might need to trawl through some of Mr Troester's stuff?

What really annoys me, are those saying I'm wasting my time because someone with a degree who's written a book "obviously" knows far more than me and should be listened to without question. (No names; Mr "I-live-in-Australia" will do).

So "RA" is not-fit-for-purpose (as typically referred to) but hopefully I can find the necessary patches and get my "project" back on track again.

It might be a relief to hear that the same book suggests the buffering capability due to grist size will diminish over time as the grist becomes more hydrated - so maybe this is not so much a factor?

I also found a couple of passages you might like…

and…

 

[peebee]

Humm ... I'm going through a bit of a disillusioned period with this "RA" business: I knew I'd seen stuff discrediting Kolbach's work and Palmer's slavish attitude towards it. But I'd past it off as "sour grapes" as I was finding "RA" so easy-peasy to introduce into what I wanted.

But seeking out this "3.5" factor and how, or even whether, it should be modified ran me straight into controversy again. Such as:

Grab the RA targets from Recipe Editor to Water Calc - Brewers' Friend Forums

Makes for uncomfortable reading! "Silver-is-Money" is a forum poster who I have a lot of respect for, in that he's taught me a lot over the years; and he doesn't seem to view Kolbach's work and "RA" too highly! I wasn't aware someone had even attempted to repeat Kolbach's work in a more realistic environment (2016: Roger Barth and his graduate student research assistant Rameez Zaman). I guess Mr Palmer won't remind everyone of it.

I think I'll cool-off on this "RA" stuff, and perhaps see what I can salvage from it.


Influence of Strike Water Alkalinity and Hardness on Mash pH

(II guess I'd better read that too - I'll try to ignore the mention of "Hardness"!).

 

[chthon]

I think there is something else regarding RA. Isn't that also an attempt at calculating the additions needed to obtain the perfect pH? That is, calculation only.

When I started brewing, I bought very quickly a pH meter, and adjusted using extra acid. I also noted my results. Perfect control, only takes some time for sampling, cooling, measuring (at most 1/2 h, actually).

I also tried Chris Colby's way of working, which goes rather well. I would certainly use it for Imperial Stout, as you need to add base instead of acid (bicarbonate).

However, based upon my notations, I currently adjust acid with amounts based upon my previous measurements, a bit guided off the cuff.

 

[peebee]

Isn't that also an attempt at calculating the additions needed to obtain the perfect pH

Yes, I think it's supposed to. I'm beginning to realise I've been here before. Only two or three months ago: Alkalinity/pH and salts again! - Homebrew Talk Forum. As I get older am I not to expect this "repeating myself" caper? Slightly different approach, slightly different emphasis, different forum (well, I've got to spread my havoc about a bit). I've found all the "RA discredited" stuff I thought I'd seen, though a bit unfair hanging the "discredited" suggestion on Paul Kolbach, 'cos it was other people making a mess of interpreting his work.

So, I can continue misusing the "RA" stuff to get a rough pointer to "beer colour" and continue dreaming of displaying the output in a contrived 2D three axis graph as a very visual water profiler calculator thingy. The RA stuff is nothing amongst the rest of it, and as long as I do not use RA to try and predict pH, I should be safe.

Job done? Case closed. Move on to next thread (and try not to repeat myself again).

Thanks

 

[peebee]

Job done? Case closed. Move on to next thread (and try not to repeat myself again).

Well ... perhaps not quite!

@chthon: I was reviewing that "Chris Colby" stuff. A bit too simplistic for me? I wasn't going to go back to teaspoons, but an interesting approach (as in, not another "water calculator"), so I was "mining" it for ideas. The "Stout" one was particularly interesting:

Brewing Liquor for Dark Beers (30–40 SRM)

It got more complicated, not less! Why was that? ... and it began to sink in! I'd always thought that paralleling "RA" with beer colour was usefully convenient; seems it's not so "convenient". But it's "convenient" for John Palmer to ignore, perhaps I was starting to put too much faith in him?

It related to a graph I'd seen it before but never took a lot of notice of it:

All the grains stacking up in a nice straight line comparing malt colour againt malt acidity (and therefore its impact on "RA"). EXCEPT them roast grains that are not playing game at all! Not enough to be concerned with? But it is for Chris Colby to mess up his "simple" approach. The roast malts are getting darker and darker, yet their "acidity" is not moving much at all ... crystal malts easily overtake them.

Why doesn't Mr Palmer high-light this?

 

[chthon]

Indeed, your beer color (actually the malts used) influence the RA, but the RA is not a predictor of beer color.

In mathematical words: RA = f(colour) is a function, but the inverse, colour = g(RA) is not a function.

 

[peebee]

Thanks @chthon: Okay! So, the conclusion must be:

1: "RA" offers very little to brewers regarding mash pH prediction, nothing at all to home-brewers. Holbach's work was never aimed at the environment in which it's much quoted and (academic, see above) attempts to repeat the work failed despite Kia Troester's (Braukaiser.com) claims of it retaining accuracy (?).

2: "RA" offers little or nothing to anyone regarding beer colour prediction.

3: Claims that "RA" offers anything useful to home-brewers by the otherwise highly thought of (in home-brew circles) John Palmer is popularist nonsense.


Not good, is it?

I'll stick Mr Palmer back in the "Home-Brew Hero" category (those abusing their academic qualifications to make money out of homebrewers by pedalling lies and untruths). Shame, it was going so well, and he seemed a pleasant enough chap. I wonder how much more of his book is utter drivel?

I'll see what I can salvage from what I was doing ... but without the "RA" stuff!

And before I get the "what do I know (with my lack of academic achievement)" ... there will be some thinking that ... I've spent a few days researching and figuring out "RA" is complete twaddle, Mr Palmer has had years! He's clever ... so, he knows it's complete twaddle.

 

[peebee]

... I also tried Chris Colby's way of working, which goes rather well. I would certainly use it for Imperial Stout, as you need to add base instead of acid (bicarbonate). ...

I've been working hard on Chris Colby's approach to water. Breaking it down so I can build a "calculator" out of it. Which probably breaks all Chris's reasons for doing it that way!

But, I want to avoid a calculator that "predicts" the resulting pH which is flippin' hard and no-one seems to do it right (they, at best, get it right for very limited ranges and very specific circumstances). Chris Colby's "empirical" approach seems much more likely to span a wider range of brewing.

As part of the nosing into it, I stick his methodology into "Bru'n Water" which makes a reasonable effort at predicting pH so provides a baseline for further work. This for a middle-of-the-range beer:

I've changed all the "teaspoon" quantities as Chris's appeared suspect (I'm using purpose-made measuring spoons). The sizes I'm using appear in "total mineral additions" column. The only "red" box is hi-lighting that the quantity doesn't provide the "desired" amount of ions … hardly surprising as that teaspoon of bicarbonate puts in 200ppm alkalinity as bicarbonate (164ppm as CaCO3). Seems a lot, but note the predicted mash pH is a very reasonable 5.39. Calcium is up at 137ppm, hence I've used a Graham Wheeler profile as "desired" (it's only there as a guide and plays no part in calculations: I'm quite surprised Chris, an "American" is recommending such high levels, but I'm good with that).

Note I'm using "full-boil volume" mash (and no additions for "dead-space", "grain absorption", "boil-off", etc., it gets un-necessarily complicated to include them). This is a point were I found Chris's technique fell apart. Let's say half the final volume of liquor is used in the mash: predicted pH is now 4.46! It's dropped because Calcium drops too if following Chris's instructions (adjust salts proportionately).

There's always the option to put the "hardness" (Calcium salts) stuff in the kettle (skip the mash), but shouldn't come to that. Loads to play with … but before that …

River looks like it might want to come in to play too (lots of rain today). I'd better go and judge my chances of survival …

 

[peebee]

... It's dropped because Calcium drops too if following Chris's instructions (adjust salts proportionately) ...

Oops! Concentration slacking 'cos mind is focuses on playful river (it's going back down again now). The amount of grain and salts stay the same, but the mash water halves, from 20L to 10L. And Bru'n Water is even less happy with this mucking about:

Hmm. Okay, I have avoided the (real) river "goin' ower me 'ead", but this (virtual) water calculation is pushing me 'ead well under. I can get the extra Calcium can be accused of causing the pH to drop, but by more than the bicarbonate forces the pH to rise?

Is some bright spark going to tell me why it's doing that?

Pleeease!