Water Treatment Questions - Bicarbonate vs Alkalinity

[phildo79]

My brain feels like it's about to implode!

I am using the Brewer's Friend water calculator and have encountered a problem. It asks for the source water and then asks if you want alkalinity shown as bicarbonate or alkalinity. I chose the latter as I had worked out the ppm value. But then in the target water profile, it asks what value you want against bicarbonate (HCO3). I have asked a friend of mine that is a chemical engineer and after doing some sums, he 'thinks' it's a 1:1 ratio. But mentioned that he was trying to work it out via my waters pH (7.10). He also mentioned that he may have got some of his numbers wrong as the ppm was far less in his total. But then I see this on the water calculator and am even more confused:

Looking at this, it would seem that HCO3 and CaCO3 are not 1:1. So what is the ratio (is it 1:1.21)? Because it asks for HCO3 in the target water profile and adding CMS/AMS affects it. I have asked and NI Water don't and won't check for HCO3 levels. They told me I would have to get a private water report done.

So I am left wondering what value I need to enter into the target profile for HCO3 in order to get the equivalent alkalinity value as ppm. I am doing a Sierra Nevada Torpedo clone so am going for an amber beer target of 35 ppm, as per @strange-steve guidelines. If I use the 1:1.21 ratio, I get a target HCO3 of 42. Is this correct? Any advice would be GREATLY appreciated.

Cheers (is it lunchtime yet so I can have a beer?)

 

[peebee]

No-one replying? That is odd. Well I'll say my bit which will be generalised so might kick off lots of arguments. But the results will be near identical.

For UK tap-water (pH 7-9) Alkalinity is caused by Bicarbonate. Bicarbonate gives the so-called "temporary hardness" so you'll find some folk who don't see the difference between "temporary hardness" and "alkalinity". You can even have "alkalinity" expressed as carbonate or as bicarbonate. Note as which is not the same as is.

This assumption works because you use UK tap-water. It will fall apart for other water sources (like sewage). And the different ways of measuring such things let's you get away with conversion factors like 1.21 or 1.22. So go with @strange-steve's guidelines of 1:1.21.

It used to fuse my head until I could conclude that what most clever dicks are saying ain't really relevant to tap-water.

 

[phildo79]

Going by the chart of adding CRS/AMS to reduce ppm, I had to add QUITE a bit more on the water calculator to get the HCO3 level down to 42. 95ml, in fact. That's because the acid level in AMS is only 15%, as suppose to the 80% in lactic acid. Adding 95ml seems like a lot! And makes me doubt the correlation between alkalinity and bicarbonate, in this instance.

 

[peebee]

Alkalinity is usually expressed as CaCO3? The equivalent as bicarbonate (HCO3-) is 1.21x that. CaCO3 barely/doesn't really exist in tap-water because the pH is too low.

If you want to scrabble your head some more look along those lines. I've already gone as far as I'm going to dare.

 

[phildo79]

Alkalinity is usually expressed as CaCO3? The equivalent as bicarbonate (HCO3-) is 1.21x that. CaCO3 barely/doesn't really exist in tap-water because the pH is too low.

If you want to scrabble your head some more look along those lines. I've already gone as far as I'm going to dare.

My tap water is 152 ppm CaCO3. I have no idea if this is high or low, compared to other areas. The online calculator turns that into 184 HCO3. If alkalinity is so important, wouldn't these online calculators make more of a big deal about it? Or at least give you an option of how you'd like the values expressed. I have yet to see the option as CaCO3, as a changeable variable.

 

[Alan_Reginato]

Hardness is related to the Ca and Mg content in water.
Temporary hardness, means that if you boil the water, the Ca will precipitate.
Alkalinity is the "ability" of water to resist acid additions, that normally would lower the pH.
Both could be expressed as caco3. Some water reports show numbers in hco3. So, that's confusing sometimes.
The first, primary, influences yeast floculation and wort protein precipitation during boil.
The second, influences mash pH. That's why it's important.

Cheers!

 

[peebee]

My tap water is 152 ppm CaCO3. I have no idea if this is high or low, compared to other areas. ...

Mine was measured as ... 8!

Is that a clue?

... The online calculator turns that into 184 HCO3. If alkalinity is so important, wouldn't these online calculators make more of a big deal about it? Or at least give you an option of how you'd like the values expressed. I have yet to see the option as CaCO3, as a changeable variable.

Ah, I can tell you that but I've just been told "come on, your dinner is going to spoil". Sorry ... will be back later (tomorrow?).

 

[phildo79]

I feel like I have chosen the wrong pill and gone far too deep into the rabbit hole

 

[Cheshire Cat]

I feel like I have chosen the wrong pill and gone far too deep into the rabbit hole

One pill makes you happy and one pill makes you small and the pill that mother gave you doesn't do anything at all. Said Alice when she's 10 feet tall.

 

[peebee]

Right, I'm back! Watch it, this is a monster post!

First off, don't get jealous of my low alkalinity water. Only about 5% of the UK population have to put up with that, mainly in the far north and west (and some anomalies elsewhere like Derbyshire - sources from Dark Peak - and Birmingham - sourced from Wales!). Alkalinity will swing about, plus or minus 10 and you wouldn't notice whereas +/- 10 has a somewhat bigger impact with my water calculations.

Next, and this will have some folk squealing, you don't need to have much of a clue about "alkalinity" (I doubt I have?). Just an idea of magnitude (like I have low alkalinity, you have medium/high ... I think?). Thing is it's a subject you have to be very knowledgeable about if you are working out your water chemistry yourself (with pen, paper and calculator perhaps) and also if designing a water treatment calculator. For the rest of us you can get away with relying on the hard work of others and use one* of their calculators.

Having an idea of the "magnitude" of your water's alkalinity lets you have an idea of what to expect - a little of that, loads of that ...

* I would recommend trying at least two calculators, 'cos the clever-dicks can't agree on the best approach, along with a half-decent pH meter. I use "Bru'n Water" and "Mash-Made-Easy". At the moment "Bru'n Water" works better for me, but it might not always be the case. "Bru'n Water" uses some old modelling apparently, whereas "Mash-Made-Easy" is more up-to-date and tweaked regularly. But Bru'n Water's" pH predictions are closer with my kooky water, but I'm still adding twice as much alkaline salt (like bicarbonate) than it suggests.

And it's pH predictions you looking at. That depends on "alkalinity". Salt additions like Epsom Salt (MgSO4) (i.e. not acids, alkalines, carbonates, bicarbonates) should be the same whatever the calculator. Don't chase small changes of pH once mashed in or you will go mad, just record it and "adapt" the recommendations next time.

Having the pH a bit wrong doesn't make undrinkable beer, and neither does getting it just right make fabulous beer that would otherwise be bad. I ended up with mashes of pH4.9 last year! It wasn't really noticeable although perhaps the dark malty beers weren't as good. I have no experience of mashed above pH5.8, perhaps you should avoid that? Way too much emphasis is currently being placed on water chemistry at the moment; meanwhile, other beer brewing aspects that make huge differences are being ignored.

I can now look forward to the flak that post will generate?

 

[phildo79]

I am currently using two calculators, brewers friend and brewfather. They pretty much match up but brewfather works out the salt addition for you, which is handy. But I will check those other ones you mentioned.

I am hoping my mate gets some of his chemistry lab nerds on the case and we get a proper answer to this (wishful thinking?). I thought he would know the answer straight away, since he has a master's degree in chemistry and is a chemical engineer. But even he says he is scratching his head over this one, so let's not hold our breath, eh.

 

[peebee]

I am currently using two calculators, brewers friend and brewfather. They pretty much match up ...

Some calculators will share the same alkalinity model and may well have the same recommendations. Perhaps what I should have said is keep trying different calculators until you find one that makes pH predictions similar to what you experience (hence I said you need a half-decent pH meter), then stick with that.

...
I am hoping my mate gets some of his chemistry lab nerds on the case and we get a proper answer to this ...

Wont happen. They'll argue like those doing it now, and you then find yourself more confused than ever.

 

[peebee]

My tap water is 152 ppm CaCO3. I have no idea if this is high or low, compared to other areas. The online calculator turns that into 184 HCO3. ...

152 x 1.21 = 183.92

QED.

Just remember, it's 152ppm As CaCO3 which you are converting to 184ppm As HCO3-. They are just convenient (and confusing!) ways of reporting, don't go looking for that stuff in reality (as I mentioned earlier, you wont find any "real" CaCO3 in your water).

 

[marshbrewer]

It will fall apart for other water sources (like sewage)

I'm thinking that alkalinity causing off flavours would be the least of your problems if you used sewage as your source water.

 

[foxbat]

My tap water is 152 ppm CaCO3. I have no idea if this is high or low, compared to other areas.

It's fair to middling and very suitable for bitters. For reference mine is knocking on 400 depending on the year which is why I don't brew with it. I think I'll hire a bowser and turn up at @peebee's place in the middle of the night!

 

[peebee]

I'm thinking that alkalinity causing off flavours would be the least of your problems if you used sewage as your source water.

Aye, in fact my water is from the pure unadulterated rain streaming over unsullied Welsh hillsides ... ahhhh ....

Hillsides covered in mucky white fluffy things (clue: Not clouds and each with four legs).

Sewage ain't far from the truth?


[EDIT: I might of put off @foxbat from hiring a bowser?]

 

[phildo79]

On the topic of messing around with water, I bought this earlier today. It says it's 100% natural so I assume it's ok to use?

 

[peebee]

On the topic of messing around with water, I bought this earlier today. It says it's 100% natural so I assume it's ok to use?

I doubt anyone at Westlab will say its okay to ingest (the term "covering me backside" springs to mind**). But it's not actually something roughly isolated from Epson well water (they do say you can't do that now), it only lists "magnesium sulphate" as an ingredient and does say "pharmaceutical grade", so it's probably near pure magnesium sulphate, and you use it in tiny quantities for brewing (sulphate is mostly supplied by calcium sulphate - gypsum - as the calcium is useful for brewing).

So looks good, and is filthy cheap. But a kilo ! That's a few lifetimes worth for home-brewing. I'd start planning on using most for it's traditional purpose ... bath salts!



On the subject of bath salts: I use "Dead Sea" salt as a source of magnesium chloride and it too is actually pharmaceutical grade magnesium chloride, which is a descent alternative to over loading with table salt (sodium chloride). Likewise though, the calcium salt (chloride) is often the preferred source of chlorides for brewing.

** Err, if you ingest too much "Epson salt" then "covering yer backside" will be a really bad move .

 

[Alastair70]

On the topic of messing around with water, I bought this earlier today. It says it's 100% natural so I assume it's ok to use?

View attachment 53841

I saw those but was worried that my mash water would start smelling of lavender or some other perfumed toiletry.
100g of MgSO4 costs £1.50 from GetErBrewed, which I expect will last between 50 and 70 brews at the rate that I am using it.

I've just read Water and the alkalinity part is totally mind bending. I'm sticking with Salfert kit at the front end and mash pH at the back. As long as the later is under 5.4 and I hit expected OG then job done.

NI water reports are not great. My Cl is given at a range of 0-160 with a mean of 36 based on only 6 samples. Even given my basic knowledge of statistics, it's clear they don't know how to present data in any meaningful way and I can have no real idea of what is coming out of the tap on a brewday.

 

[phildo79]

I doubt anyone at Westlab will say its okay to ingest (the term "covering me backside" springs to mind**). But it's not actually something roughly isolated from Epson well water (they do say you can't do that now), it only lists "magnesium sulphate" as an ingredient and does say "pharmaceutical grade", so it's probably near pure magnesium sulphate, and you use it in tiny quantities for brewing (sulphate is mostly supplied by calcium sulphate - gypsum - as the calcium is useful for brewing).

So looks good, and is filthy cheap. But a kilo ! That's a few lifetimes worth for home-brewing. I'd start planning on using most for it's traditional purpose ... bath salts!



On the subject of bath salts: I use "Dead Sea" salt as a source of magnesium chloride and it too is actually pharmaceutical grade magnesium chloride, which is a descent alternative to over loading with table salt (sodium chloride). Likewise though, the calcium salt (chloride) is often the preferred source of chlorides for brewing.

** Err, if you ingest too much "Epson salt" then "covering yer backside" will be a really bad move .

I went looking for kosher salt yesterday (or rock salt) as a source of sodium chloride. No joy at the supermarket. They did have flaked sea salt but there were no details about iodine content.