Alkalinity variation in water supply

[Taket_al_Tauro]

Hi,

I’m seeking some advice from the revered water chemistry experts on this board .

I moved to a new place recently, and unfortunately, I just discovered that my water supply is inconsistent. According to my municipality, I am getting water from two distinct sources: one has (very) high alkalinity, around 300 ppm, while the other has a more moderate alkalinity in the range of 120-130 ppm. It seems I am getting mostly the very alkaline one (call me lucky), yet I have no means of knowing how much of the lower alkalinity water is being mixed-in at any moment. This varies depending on water use peaks, source water availability, and other factors…so the water flowing from my taps might well have, say, 200 ppm alkalinity in the morning, and 300 ppm in the evening. Calcium aside, mineral contents are very low and comparable for both sources.

Now, I know what many of you are going to advise me under such circumstances: get a RO system! ..and it might indeed be the wisest piece of advice. Yet at my previous house, I managed to brew what I thought were good beers, also the light-coloured ones, using alkaline water (ca. 220-250 ppm alkalinity). Without using any RO water, but of course I did adjust the water with acid.

So based on this experience, my plan is rather to collect all my brewing water at once before each brewday (mash+sparge and maybe even top-off water), measure its alkalinity using one of those cheap aquarium alkalinity drop-tests, plug the results into Brun Water and adjust accordingly. I’m going to get a pH meter as well, so that will allow me to double check things and also fine-tune my mash and wort pHs.

Could this be a workable plan, or am I missing something? In general, are those aquarium alkalinity drop-tests accurate and reliable enough for our needs? To my understanding, it’s like doing a titration, i.e. you count the amount of drops until the solution changes colour. So I guess it should be fairly accurate?

Thanks in advance for your opinions!

 

[mabrungard]

That is a reasonable plan as long as the other water mineralization is suitable and otherwise consistent While testing is an extra step, it should enable you to work with your water.

 

[Vale71]

Those test if properly used should be accurate enough that you will hit your target mash PH consistently, assuming calcium and magnesium content varies proportinally to total alcalinity. If those vary too then you would need to measure for Ca and Mg as well and that will become more expensive but still doable.
What you won't get though is consistency. Whilst you will hit your target PH the taste in the finished beer will still be affected by mineral content and if that varies a lot you might be able to detect differences between batches. Magnesium is particularly bad and I'm so sensitive to it that I can actually taste it in mineral water if content exceeds 15-20mg/l. If your goal is total consistency then I'm afraid RO water is as of today the best solution to all your problems...

 

[Big Monk]

Hi,

Now, I know what many of you are going to advise me under such circumstances: get a RO system! ..

I personally use bottled Distilled water. I grab 10 gallons in the beginning of the week when i know I'm going to brew. At $0.89 per gallon, this adds < $10 to my overall cost and gives me peace of mind knowing I have a clean slate to work with.

 

[Taket_al_Tauro]

That is a reasonable plan as long as the other water mineralization is suitable and otherwise consistent While testing is an extra step, it should enable you to work with your water.

Thanks Martin, that's reassuring! Yes the remaining mineralization seems consistent, basically low in everything but calcium. Mg of the harder source is around 20 ppm. SO4 and Cl are in the order of 5 - 20 ppm. So basically I think I can take my water as more or less of a clean slate with respect to SO4/Cl

 

[Taket_al_Tauro]

Those test if properly used should be accurate enough that you will hit your target mash PH consistently, assuming calcium and magnesium content varies proportinally to total alcalinity. If those vary too then you would need to measure for Ca and Mg as well and that will become more expensive but still doable.
What you won't get though is consistency. Whilst you will hit your target PH the taste in the finished beer will still be affected by mineral content and if that varies a lot you might be able to detect differences between batches. Magnesium is particularly bad and I'm so sensitive to it that I can actually taste it in mineral water if content exceeds 15-20mg/l. If your goal is total consistency then I'm afraid RO water is as of today the best solution to all your problems...

Thanks! From what I understand I think I can make this assumption that Ca and Mg contents vary proportionally to total alkalinity. That's because both sources are very low in all anions other than carbonates. So nearly all Ca and Mg in both sources must come from the respective carbonates, right?
Concerning Mg: worst-case scenario I'll have around 20 ppm Mg in there. This if I'm getting the harder source exclusively. And it will be less than that with some water from the softer source in the mix.

 

[Silver_Is_Money]

Get a GH (general or total hardness) test kit along with the KH (alkalinity) test kit. Often they are sold together.

Total Hardness = (2.5 * Ca++) + (4.12 * Mg++)

As a ballpark, roughly 70% of GH (total hardness) is derived from Ca++, and 30% of GH is derived from Mg++.

Therefore:
------------
Ca++ ~= 0.70*GH/2.5
Mg++ ~= 0.30*GH/4.12

17.848 * dH = ppm
(where d = either G or K, depending upon which test you are doing)

My source for the above is Kai Troester. I have (in the past) asked for the above to be made into a sticky, but A.J. deLange was vehemently opposed to having this be made into a sticky (so it never was).

 

[Taket_al_Tauro]

Get a GH (general or total hardness) test kit along with the KH (alkalinity) test kit. Often they are sold together.

Total Hardness = (2.5 * Ca++) + (4.12 * Mg++)

As a ballpark, roughly 70% of GH (total hardness) is derived from Ca++, and 30% of GH is derived from Mg++.

Therefore:
------------
Ca++ ~= 0.70*GH/2.5
Mg++ ~= 0.30*GH/4.12

17.848 * dH = ppm
(where d = either G or K, depending upon which test you are doing)

My source for the above is Kai Troester. I have (in the past) asked for the above to be made into a sticky, but A.J. deLange was vehemently opposed to having this be made into a sticky (so it never was).

Thank you!
That is very useful information!

As a side note, there is a further complicating factor with my water. Didn't mention that in my original post since I did not want to start the thread in such an intricate manner ;-). Anyway, In my apartment building there's one of those water softeners that exchange Ca and Mg ions for Na... the water flowing from my taps is only partially softened, since there is definitely some calcium left in there. Probably they are mixing the softened water with the raw one, to save some costs and/ or keep the Na content at moderate levels. In any case, I can't taste even the slightest hint of saltiness in my water.
So I think (and hope) that the Na-level is not hitting the problematic threshold.

But with the alkalinity and GH test and the formulas you suggested, I should be able to roughly estimate the Ca and Mg content in the softened water, and with that ( and Brun Water) I should even be able to get an estimate of the Na content provided by the softener.

Anyway, some Na can be positive as suggested in a brulosophy exbeeriment, so I'm going to give it a try!

 

[Taket_al_Tauro]

Thanks again for all the useful responses !

 

[Vale71]

You can't use softened water to brew at all, the reason being the softener will replace Ca and Mg with Na but it won't remove carbonate at all so that your residual alcalinity will skyrocket. You either have to look for a way to bypass it or use RO or bottled water instead.

 

[Taket_al_Tauro]

I know the softener won't remove any alkalinity. This will stay the same, right? But as stated above, I'll be taking care of the alkalinity with acid (phosphoric). Additionally, I'm planning gypsum and CaCl additions and that will also compensate for the partial calcium removal by the softener.

I know common advice is not to use such softened water, but after doing some more research, I actually convinced myself that I might even be better of using my partially softened water than the original one, which might contain very high levels of Calcium on it's own ...not considering my subsequent calcium additions with gypsum and CaCl.

Or am I still missing something important here?

 

[Vale71]

I know the softener won't remove any alkalinity. This will stay the same, right?

No it won't and that's what makes the water unsuitable. The Ca and (much less) the Mg partly neutralize the carbonate, thus reducing your residual alkalinity. If you remove the Ca and Mg but not the carbonate your residual alkalinity will skyrocket and your mash PH will increase to unacceptable levels. Of course you could replace the missing Ca and Mg with CaSO4 or CaCl2. Once in solution a calcium ion will have the same effect as the one that was there in the first place, but can your beer really tolerate the resulting levels of SO4 and Cl ions?
If your water had a lot of hardness to begin with - which is a safe assumption otherwise you wouldn't have a water softener installed in the first place - you are looking at really huge additions, plus all the Na and the carbonate that you can't get rid of.
Trust me, such a beer will invariably taste very awful. You would be really much better off using your original, untreated water.

 

[Taket_al_Tauro]

OK, thanks for the inputs. I should think it over again then... Based on what I read I would definitely not use 100% softened water. But as I said, my water is only partially softened so I thought it might work given the correct salt and acid additions.
There is most definitely still a significant amount of calcium in there.
Besides, I'm not sure there is a way to bypass the softener since I live in an apartment and the
softener is installed centrally for all apartments in the building. I should ask the housekeepers whether there is such an option.
As for SO4/Cl: In any case I'll add gypsum and CaCl2 only to reach about 180 ppm SO4 and 80 ppm Cl-, not more than that.

 

[Big Monk]

OK, thanks for the inputs. I should think it over again then... Based on what I read I would definitely not use 100% softened water. But as I said, my water is only partially softened so I thought it might work given the correct salt and acid additions.
There is most definitely still a significant amount of calcium in there.
Besides, I'm not sure there is a way to bypass the softener since I live in an apartment and the
softener is installed centrally for all apartments in the building. I should ask the housekeepers whether there is such an option.
As for SO4/Cl: In any case I'll add gypsum and CaCl2 only to reach about 180 ppm SO4 and 80 ppm Cl-, not more than that.

Do yourself a favor and just procure some distilled water from the store and build from there.

When trying to use tap water becomes this much of a hassle/guessing game, it’s time for a clean slate.

 

[Taket_al_Tauro]

Do yourself a favor and just procure some distilled water from the store and build from there.

When trying to use tap water becomes this much of a hassle/guessing game, it’s time for a clean slate.

Then a RO system would be the best option for me in the long run, since store distilled water is expensive over here. With the cheapest one I can find I would spend between 17 - 22 $ just in water for a 5 gal batch.

But then again, I'm probably a stubborn fool, but I know from experience that it is possible to make both
very good and also consistent brews using alkaline tap water, given the proper acid and, depending on style, salt additions.

That has been my experience during my last 1 1/2 years of brewing at my old apartment, and it was not only me judging the resulting beers. Maybe I've just been lucky and always managed to hit an acceptable water profile, who knows.

In any case, I'll give it a try with the water I have before investing time and money in a RO system. But I'll definietely try to find out if there is a way to bypass that water softener and tap some original, hard water for my brewing.

 

[ajdelange]

If you remove the calcium and magnesium your RA won't "skyrocket". Calcium and magnesium have a modest effect on RA. The formula is

RA = alkalinity - (Calcium Hardness + 0.5*Magnesium Hardness)/3.5. Thus if you have water with no permanent hardness e.g. 2 mEq/L alkalinity and 2 mEq/L calcium hardness RA = 2 - 2/3.5 = 1.42. Remove the calcium altogether and RA goes up to 2 i.e. by 40%. That's appreciable but is hardly "skyrocketing". Besides which RA's effect on mash pH isn't that profound. RA in and of itself isn't really that interesting to someone concerned with predicting mash pH - it's really for comparing water sources. Good brewing software usually doesn't even compute it (though you could say it is implicitly considered in good brewing software).

The real "damage" a water softener does is to leave the alkalinity alone i.e. it doesn't really do that much damage. You will still have to deal with the alkalinity but as has been noted there are ways to do this. Now if you have stripped out the calcium you have also removed the ability of the water to decarbonate itself (reduce alkalinity) by boiling or lime treatment. You can always replace the calcium you took out and still do this but that's just making extra work for yourself. If you have a softener it is generally better to bypass it (most modern ones have a shuttle valve that easily lets you do that) or you can install a simple piercing valve upstream of the softener.

The easiest way to deal with alkalinity is to have none (RO system) but if you want to work with water whose alkalinity is subject to unpredictable variation the next best solution is to 0 out the alkalinity by adding acid until the pH of the treated water reaches the desired mash pH. Then tell your brewing software that you are using water with no alkalinity (or no bicarbonate if it is one of those that thinks of alkalinity of bicarbonate).

 

[Vale71]

Well I guess we have different definitons of skyrocketing. If I have water with high RA and am trying to get it down to a slightly negative number then increase it by 40% to begin with is definitely a step in the completely wrong direction.

 

[Taket_al_Tauro]

Thanks AJ also for your input. Well well, after reading again the Brulosophy Sodium exbeeriment
(http://brulosophy.com/2018/01/22/wa...impact-of-sodium-on-beer-exbeeriment-results/), and your comment, I feel more intrigued than ever and adventurous enough to even try brewing with my partially softened water. But first I'll definitely try to get a rough estimate of the sodium contect in said water. If that approaches or even exceeds
the 150 ppm, I'll definitely not brew with it. But for several reasons I don't think it will be in that range.

Anyway I'll try and post back here with the results. If the beer (an AIPA) will indeed turn out less than stellar,
I'll give full credit to your arguments, Vale71!

 

[ajdelange]

Well I guess we have different definitons of skyrocketing.

You can certainly define "skyrocket" any way you like.

If I have water with high RA and am trying to get it down to a slightly negative number then increase it by 40% to begin with is definitely a step in the completely wrong direction.

If your goal is to set pH with calcium then removing it, even the smallest bit, is a step in the wrong direction but I don't think you appreciate how small the effect of calcium is. For starters, Kolbach's observed shift in pH caused by calcium (1 mEq protons released per 3.5 mEq of calcium) was observed at knockout). As we know that further pH reduction takes place in the boil when calcium is present it is clear that the full effect of calcium will not be seen in the mash. Many of the Gen I spreadsheets assume that it is all seen in the Mash and Martin, for example, argues that it is. I don't know what fraction is released in the mash so I usually assume that it is half. The following is based on that assumption. Let's suppose we have water with 2 mEq/L alkalinity and 7 mEq/L hardness. The RA is 0. Remove .01 mEq/L calcium (.2 mg/l) and the RA is no longer 0 but it has increased by an infinite percentage. This helps to illustrate why RA isn't such a good parameter to think about when trying to esimate mash pH.

To continue, suppose we are mashing 88.3% Pilsner malt with 10.4% 20L caramel and 1.2% sauermalz in a 1.28:1 thickness mash. This would give us a mash pH of 5.50. Now repeat with the water run through a softener. All the calcium is gone and replaced with 7 mEq/L sodium (161 mg/L). The pH would rise to 5.56. Now that is enough to get your attention certainly I wouldn't think of it as "skyrocketing" It could be made up for by increasing sauermalz to 3.0%. I'd be more concerned about the 161 mg/L sodium.

Note also that in this example we used water that is very hard (350 ppm as CaCO3). Water that is less nominally hard would give less of a pH rise if softened. Consider a more nominal water with 2 mEq/L (100 ppm) calcium hardness to balance the 2 mEq alkalinity. We'd need 1.8% sauermalz for pH 5.50 with the calcium present. With it stripped out by a softener pH would go to 5.53, which can be compensated for by going to 2.0% sauermalz and the sodium would only be 46 mg/L. Thus it is evident that with more or less nominal water you can very well make beer after going through a softener. With much more alkaline water you still can but have to accept higher sodium levels and use more sauermalz.

None of the above is to be interpreted as saying that you should use softened water but if you have to you can. I made lots of beer with softened water before I knew any better.

 

[Taket_al_Tauro]

I asked the company that installed and manages the softener in my building. The system is set to leave between 80 and 100 ppm permanent hardness in the water. Now in my worst-case scenario, if I'm getting 100% water from the harder source (which has 330 ppm permanent hardness), and the system softens it down to 80 ppm, it'll remove 250 ppm permanent hardness. Thanks to the formulas in a post above kindly provided by Silver_is_money, and by AJ (from another thread) I could estimate a sodium concentration of about 150 ppm in my softened water. (AJ feel free to correct me if I'm wrong here ;-)). The original water has an almost negligible sodium content of about 5 ppm.
So that is the worst case scenario for sodium, but as I'm actually getting some kind of mix between the hard and the softer source, I believe Na will more likely be around 100 ppm, which is the concentration used in the brulosophy experiment.

 

[ajdelange]

If it takes out 250 ppm and if we are sure that that number represents hardness as calcium carbonate then that amounts to 5 mEq/L removed which is replaced with 5 mEq/L sodium at 23 mg/mEq for 115 mg/L sodium added (plus, of course, the 5 already in the water).

 

[Taket_al_Tauro]

If it takes out 250 ppm and if we are sure that that number represents hardness as calcium carbonate then that amounts to 5 mEq/L removed which is replaced with 5 mEq/L sodium at 23 mg/mEq for 115 mg/L sodium added (plus, of course, the 5 already in the water).

Ok, thanks! That would make my worst-case scenario even less "severe ".
And with some of the softer water in the mix, Na would probably be more likely in the 70 - 100 ppm range.

 

[Big Monk]

Ok, thanks! That would make my worst-case scenario even less "severe ".
And with some of the softer water in the mix, Na would probably be more likely in the 70 - 100 ppm range.

I’d still argue that in your situation, store bought Distilled or RO water is preferable.

There are enough things to have to worry about on brewday without having water composition be an unknown and possible hinderance.

 

[Taket_al_Tauro]

I’d still argue that in your situation, store bought Distilled or RO water is preferable.

There are enough things to have to worry about on brewday without having water composition be an unknown and possible hinderance.

Well, hopefully not so much of an unknown since I'll be taking both permanent and temporary hardness measurements and adjust from there. I esteem that should put me at least at the same level of confidence as having a more stable water supply but relying on a municipal report for my adjustments (which I did until now with good results).

Of course RO would give me an even greater level of accuracy and flexibility. But for several reasons I'm not willing to make that move yet. For one, I might be able in a foreseeable timeframe to set up shop in a place that has naturally softer water. I don't want to invest in a RO system that I might soon not need anymore.

But I concede that RO woul most probably be the wisest thing to do in my current situation!

 

[Taket_al_Tauro]

Just wanted to report back on the IPA I brewed using my less than ideal tap water (alkaline and partially softened), and say big thanks to all who contributed here, also those who tried hard to scare me away from using such water. You made me look even deeper into my water adjustments and overall process.

So the beer turned out really good. Great hop flavor/aroma, no harsh bitterness or astringency.
It is quite possibly the best IPA I ever brewed (though I know, homebrewers tend to say that alot when talking about their latest efforts ;-)).
But at least for me, that was a confirmation that it is possible to brew good tasting beer with suboptimal water, provided one takes the necessary measures with respect to acidification and overall water adjustments.

Here the details of my water profile and adjustments for those that might be interested:
- Alkalinity (measured with drop titration test): 240 ppm
- Total hardness (measured wit drop titration test): 140 ppm (remember the water is partially
softened through ion-exchange, that is why total hardness < alkalinity)
- Calcium (estimated from total hardness thanks to the formula provided by @Silver_Is_Money): 40 ppm
- Magnesium (also estimated from total hardness): 10 ppm
- Sulfate (from municipal water report): 17 ppm
- Chloride (from municipal water report): 7 ppm
- Sodium (essentially provided by the water softener, and estimated from the above values using Bru'n Water): 63 ppm

I then adjusted both mash and sparge liquor with phosphoric acid, CaSO4 and CaCl2 to get to approx 180 ppm sulfates and 90 ppm chlorides in my brewing water, and to attain a mash pH of 5.4 (and sparge water alkalinity of about 25 ppm).

Thanks again and cheers!

 

[cire]

Well done. Good to read and pleased to know of another treating their own water.
Good luck for continuing advancement.