High Alkalinity

My water is very high in alkalinity – over 300 ppm in HCO3. What are my options to mitigate?
If I boil, I understand that lowers the HCO3, but what else does that affect? Plus I never know how long to boil and it’s really a hassle.
I’ve used phosphoric acid in the past to get the mash pH to an acceptable range, but seems like I’m using a lot of acid. What’s physically changing in the water profile when I use phosphoric acid? What’s the effect on taste?
What are some other alternatives? Or am I just better off going with an RO system?

Thanks!

Wallonia said:

My water is very high in alkalinity – over 300 ppm in HCO3. What are my options to mitigate?

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1. Don't use this water
2. Process the water through a softener followed by an RO unit. This is really equivalent to 1.
3. Boil the water to precipitate CaCO3 (reduce alkalinity and hardness)
4. Treat the water with lime to precipitate CaCO3. Same result, essentially, as 3 but no heat.
5. Treat the water with acid.
6. Dilute with RO water and use acid too.

Wallonia said:

If I boil, I understand that lowers the HCO3, but what else does that affect?

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The reaction is Ca++ + 2HCO3- --> CO2 + CaCO3 + H2O so that both bicarbonate (alkalinity) and calcium (hardness) are removed.

Wallonia said:

Plus I never know how long to boil and it’s really a hassle.

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It isn't really necessary to boil if you use some other means to remove the CO2 such as spraying the hot water through a nozzle or sparging it with air or nitrogen. If you boil you are using steam for this purpose. A few minutes of boiling should be sufficient.

Wallonia said:

I’ve used phosphoric acid in the past to get the mash pH to an acceptable range, but seems like I’m using a lot of acid. What’s physically changing in the water profile when I use phosphoric acid?

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The reaction here is
2H3PO4 + 3HCO3- --> H2PO4- + HPO4-- + 3CO2 + 3H2O
(approximately). You are swapping bicarbonate ions for mono and di basic phosphate ions.

Wallonia said:

What’s the effect on taste?

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I don't know which is a testament to the low flavor contribution from phosphate. Nonetheless I'd prefer to remove most of the alkalinity by means of boiling or lime and then trim with acid rather than doing the whole job with phosphoric acid.

Wallonia said:

What are some other alternatives?

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Lime treatment:

Ca++ Ca(OH)2 + 2HCO3 --> 2CaCO3 +2H2O

Wallonia said:

Or am I just better off going with an RO system?

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I think so but you do have to buy, install and maintain them.

Well how's that for a welcome to HBT. Awesome response.

TyTanium said:

Well how's that for a welcome to HBT. Awesome response.

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Yup, that's AJ. Totally to the point and totally amazing!

Wallonia, where in Belgium are you? That's some kind of water you got there.

AJ nailed all the options. It depends how inexpensively you want to proceed. Adding phosphoric is simple. Boiling and decanting is simple too. Neither of those options is very expensive. Moving to a RO water may be more costly in terms of a capital cost for the machine or in terms of the inconvenience of having to find a RO vending machine and transporting water.

Thanks all. I'm in the Hainaut region close to Ath. Water here is pretty hard. Actually what I find most around here is that the Ca and Mg ranges are normal but HCO3 is super high.

I wasn't aware that acid actually got rid of the HCO3. Am I getting rid of other things by using acid? It's easy enough and cheap so I don't mind using it, but want to make sure I'm not hurting another area of the water profile.

I'm still trying to wrap my arms around very basic water chemistry...really appreciate the help.

I think AJ has just about all of the info and options.

Really, for me, it boils down to (pun intended) either mixing your water with some RO or Distilled water, or just buying an RO system and using that water with some added minerals.

If you brew enough, an RO system at home is actually not outside the realm of possibility. I can buy one online for about $150 that is pretty decent sized for this. If you only brew once in a while, it might be cheaper to buy RO or Distilled water from the store and mix with your water using different ratios for different styles of beer.

I'm currently using a combination of phos. acid and mixing with RO water. The mixing with RO helps to limit the amount of Phos I use. I'd prefer to do away with the phos, so I'm thinking about getting an RO system for the house.

Wallonia said:

Am I getting rid of other things by using acid?

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Acid neutralizes base (which is responsible for alkalinity). The only base that should be in potable/brewing water is carbonate/bicarbonate thus you should not be removing anything else by using it.

Wallonia said:

It's easy enough and cheap so I don't mind using it, but want to make sure I'm not hurting another area of the water profile.

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As I noted in #2 acid replaces bicarbonate ion with an equivalent (chemical equivalence which means a like number of electrical charges) amount of it's anion. Thus the way in which one can hurt the water profile by use of acid is if the alkalinity is high enough that replacing the bicarbonate results in a level of acid anions sufficient to introduce an undesired flavor. Alkalinity at 300 ppm as CaCO3 has an equivalence of 6 mEq/L. Replacing that much bicarbonate with sulfuric acid would result in a sulfate level of 288 mg/L. That is a lot of sulfate but not more than some people enjoy in some beers. Replacing that much bicarbonate with hydrochloric acid would result in 213 mg/L chloride ion. That is more chloride ion than most would want in most beers. With phosphate the actual amount and distribution (between mono and di basic forms) will depend on the pH realized. In any case there will be lots of phophate but malt itself contains lots of phosphate as it is so I doubt that the amount of phosphate released in neutralizing 300 mg/L alkalinity would be enough to introduce an off flavor.

Thanks again!

Okay -- it's been a while and I'm coming back to this one. I bought the Palmer/Kaminski book on water, but it's hard to follow for someone with an attention span and chemistry background of a 2 year old.... I'll get there. Just need some time!

Anyways, I still struggle with residual alkalinity. I've recently starting paying very close attention to pH and it's definitely paying off in terms of beer quality and mash efficiency. But the amount of acid I have to use to get the pH to 5.5 seems ridiculous. That said, phosphoric acid is easy to use and I don't notice any affect on flavor. I just want to make sure that by using phosphoric acid I'm not doing anything to the Ca profile. I don't think I am from my understanding of the chemical reaction taking place but need a bit of reassurance.

Thanks as always!

4. Treat the water with lime to precipitate CaCO3. Same result, essentially, as 3 (boiling) but no heat.

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In my experience, boiling doesn’t do much, but lime softening is remarkably effective. I still end up using about the same amount of acid.

I am curious about the flavor contribution of bicarbonate. I made a batch of Pale Ale with 100% RO, with no salts at all. Compared to acidified 100ppm alkalinity water, it was a little thinner and sweeter, with more hops. That’s not just me, but the consensus of a dozen or so judges. I realize it’s basically a sample of one, but I’d like to hear from people that switched to RO from phosphoric acid.

Wallonia said:

I bought the Palmer/Kaminski book on water...
I just want to make sure that by using phosphoric acid I'm not doing anything to the Ca profile.

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If there is a lot of calcium in the water it can react with the phosphate and some will precipitate. There are some curves at the back of the book that tell you how much calcium you can tolerate before this starts to happen.

Wynne-R said:

In my experience, boiling doesn’t do much, but lime softening is remarkably effective. I still end up using about the same amount of acid.

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Is that what you really meant to say? If you use the same amount of acid either way then both methods are equally effective.

Wynne-R said:

I am curious about the flavor contribution of bicarbonate.

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It's awful but the good news is that at mash, kettle and especially beer pH there isn't much. Even starting with fairly alkaline water most of the bicarbonate in finished beer comes from the CO2 used to carbonate it.

Wynne-R said:

I made a batch of Pale Ale with 100% RO, with no salts at all. Compared to acidified 100ppm alkalinity water, it was a little thinner and sweeter, with more hops.

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One of the things chloride does for beer is contribute to body (or, more probably, the perception of body). Beer made with water totally devoid of chloride tends to be, as you say, rather thin and insipid. But chloride is also a sweetener.

In my experience, boiling doesn’t do much, but lime softening is remarkably effective. I still end up using about the same amount of acid.

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That is what I meant to say but it seems to be misleading.

The boiled water retains most of it’s alkalinity and is essentially the same as un-softened tapwater. Testing with an aquarium KH test kit, tapwater 100ppm, boiled water 80ppm, and lime softened less than 20ppm. The boiled water has a bit of limestone precipitate, but the slaked lime has a bunch.

After I rack off the lime softened water the pH is 10+ and I use about .6 mL of 85% phosphoric acid to get the pH below 6 with 8L. This is the same amount I use with the untreated water to get to the same endpoint.

I tried adding calcium chloride to the glass with the RO batch and it didn’t do much. I tried calcium sulfate and I didn’t care for the sulfate. Sea salt helped.

Thanks AJ for all you do for beer. Making the world better one batch at a time.