Brun Water - why adding acid doesn't inrease calcium need?

[Fore]

Not unsurprisingly, water remains the most confusing part.

In my first AG this weekend, I think I hit target pH in the mash, more or less. But this question is about batch sparge water.

I didn't add acid to my sparge water, as I didn't see it as necessary. If I understand right, I need only worry about pH in the mash. However, good levels of calcium in the sparge water will aid the rest of the process. And this is where I'm not really clear on Brun Water and how it reacts to input.

From what I think I know, if you add acid, you strip out bicarbonates, but also unfortunately some calcium, so you need to add some back to replace what the acid stripped out. So I would have imagined, in Brun Water, that if you added acid, then the required calcium addition would increase, but it doesn't. I spotted this because I worked out needed calcium addition for the mash, including acid, but then also separately just for the sparge water, without acid. The calcium addition was identical in both cases, but I would have imagined that more would be needed in the case you add acid.

Where am I going wrong in my understanding?

 

[MyQul]

I'm very far from a water treatment expert as I've only just started doing water treament myself.
But my understanding of it is, Bicarbonate Calcium is 'bad' calcium as it increases mash PH whereas calcium chloride or calcium sulphate it 'good' calcium as it suppresses harshness and astringent flavours as well as helping to lower PH further. So I'm thinking your not trying to replace like for like as there two different 'sorts' of calcium doing two different things. Your just trying to replace enough CalSuphate/Calchloride to get the benefits perhaps rather than replace the exact amount of calcium stripped out.
So you might not necessarily need more CalSulphate/Calchloride in the mash because you've striped out more with the acid. I don't know for sure though. Just making some assumptions on the reading I've done

Edit: Also seeing as though Calsuphate/Calchloride also reduces your mash PH you wouldn't want to add more than in the sparge as the acid is reducing the PH along with the malt too - but following that train of thought, you'd just add less acid wouldn't you - :hmm:

 

[Fore]

Glad to see I'm in good company with these questions :smile:.

I just re-read Graham Wheeler water treatment section, and I believe I have a new hypothesis. Are you ready for this... It might be only BOILING that reduces calcium, in that it's CALCIUM carbonate that falls out with boiling, whereas acid is a completely different approach, pulling out the unwanted bi-carbonates in a more complex chemical reaction. So if you use acid, then the calcium addition needed is simply a function of your water, not connected at all to the acid you might add.

So if you had really high levels of bicarbonate and were planning a pale beer, then you would either need to add a lot of acid, or you would boil first. The advantage of boiling being that the level of acid then needed is greatly reduced (possibly to zero). And if you did boil, then you'd need to measure the calcium content after boiling to know how much to add to reach target.

God I actually sound like I know something. Now someone far more intelligent will make me sound stupid...

 

[MyQul]

Were like two blokes groping about in the dark, aren't we :lol:

I also have GW book. According to that you don't need any acid at all if you boil for 30 mins as boiling precipitates all the Calcium BiCarbonate out. He also doesn't make any mention of measuring your calcium content or using any real sort of calculation/online calculator to work out how much calcium to add back. He just says to add about 100g of calcium sulfate before you boil and by trial and error see if this brings your mash PH into the correct range.

As to your hypothosis, I have no idea as I haven't done enough reading to either agree with it or spot any flaws in it

 

[HebridesRob]

Were like two blokes groping about in the dark, aren't we :lol:

I also have GW book. According to that you don't need any acid at all if you boil for 30 mins as boiling precipitates all the Calcium BiCarbonate out. He also doesn't make any mention of measuring your calcium content or using any real sort of calculation/online calculator to work out how much calcium to add back. He just says to add about 100g of calcium sulfate before you boil and by trial and error see if this brings your mash PH into the correct range.

As to your hypothosis, I have no idea as I haven't done enough reading to either agree with it or spot any flaws in it

Not 100g not possibly.

 

[MyQul]

Not 100g not possibly.

Sorry, not 100g, he states 100mg/L

 

[HebridesRob]

Glad to see I'm in good company with these questions :smile:.

I just re-read Graham Wheeler water treatment section, and I believe I have a new hypothesis. Are you ready for this... It might be only BOILING that reduces calcium, in that it's CALCIUM carbonate that falls out with boiling, whereas acid is a completely different approach, pulling out the unwanted bi-carbonates in a more complex chemical reaction. So if you use acid, then the calcium addition needed is simply a function of your water, not connected at all to the acid you might add.

So if you had really high levels of bicarbonate and were planning a pale beer, then you would either need to add a lot of acid, or you would boil first. The advantage of boiling being that the level of acid then needed is greatly reduced (possibly to zero). And if you did boil, then you'd need to measure the calcium content after boiling to know how much to add to reach target.

God I actually sound like I know something. Now someone far more intelligent will make me sound stupid...

Essentially correct. Depends on the acid, some acids would produce insoluble calcium salts, which would precipitate out as calcium carbonate does.

There are other reasons for acidifying sparge water; lower pH water leeches fewer tannins from the grain, for example.

I've posted these before but this series of articles are good to read...
http://www.braukaiser.com/wiki/index.php?title=An_Overview_of_pH
http://www.braukaiser.com/wiki/index.php?title=How_pH_affects_brewing
http://www.braukaiser.com/wiki/index.php?title=Mash_pH_control

 

[Fore]

Essentially correct.

Oh, this is really turning a corner. Finally I might be getting somewhere with this. Thank you.

Still on the subject of Brun Water then, now very specific to it and really tying this down for me... why on the 'Adjustment summary' tab is my red dot nowhere near any of the historic profiles? I do at least reach target mash pH, say 5.4 region, and that is my goal as I understand it, but my red dot is way off down at 202 hardness and 9 alcalinity. That's a residual alkalinity of -50 and most "normal" profiles are well into positive RA. Even Pils is at about 0 RA (and Burton also but only due to extreme hardness).

Yet I needed this acid and calcium addition to reach target pH. So why is my RA not anywhere near the norm?

 

[HebridesRob]

Oh, this is really turning a corner. Finally I might be getting somewhere with this. Thank you.

Still on the subject of Brun Water then, now very specific to it and really tying this down for me... why on the 'Adjustment summary' tab is my red dot nowhere near any of the historic profiles? I do at least reach target mash pH, say 5.4 region, and that is my goal as I understand it, but my red dot is way off down at 202 hardness and 9 alcalinity. That's a residual alkalinity of -50 and most "normal" profiles are well into positive RA. Even Pils is at about 0 RA (and Burton also but only due to extreme hardness).

Yet I needed this acid and calcium addition to reach target pH. So why is my RA not anywhere near the norm?

If you read those links I posted carefully the answers are provided...
1. "Historic profiles" are mythological, they're based on typical water for the regions the beers were made. The brewers operating in those regions would have been using non-typical water from their own wells (or whatever).
2. It's better to get near to 5.2pH really. Don't stress over it though.
3. Residual alkalinity isn't relevant, except as a measure of how to treat the water. It isn't about the pH of the actual water. It's the pH of the mash that matters. Salts buffer the acids present in the mash by (simplistic) capturing excess, or releasing extra, H+ ions. This keeps the pH in balance.
4.Too high levels of salts might adversely affect the taste of the beer, might even be a little dangerous.

 

[Fore]

Super, you put my mind at rest. Thank you again.

I will be reading your links, for sure. I've been reading up about water for some months, off and on. In the early stages, I thought I knew about something, but then discovered I was completely wrong. Slowly but surely it started to make sense and now it starts to cement.

I believe my first and only mash was about 5.2pH, so I think the studying paid off. It still seems strange putting acid in your water though.

Next for me is improved understanding of taste thresholds, and ratios.

 

[nickwhiteley]

HebridesRob, I have been trying to understand pH in brewing for about a year now. Your articles are the most comprehensive and accessible I have seen. Thank you.

 

[HebridesRob]

HebridesRob, I have been trying to understand pH in brewing for about a year now. Your articles are the most comprehensive and accessible I have seen. Thank you.

I think they're excellent.

 

[mabrungard]

The only acid that will precipitate calcium is phosphoric acid and that reaction will only occur if the calcium content is already high. If its already that high, it certainly doesn't matter that the calcium was lost to precipitation. Bru'n Water doesn't calculate that loss since the precipitation reaction is actually a pretty complicated reaction.

An important fact is that we don't really need ANY calcium in our brewing water since malt supplies all the calcium that the yeast need for their metabolism. However, including calcium in the brewing water is helpful in ale brewing since it speeds the flocculation of yeast and clearing of the beer. Don't worry too much about calcium loss.

 

[mabrungard]

Oh, by the way. If your water has much alkalinity (say >25 to 50 ppm as CaCO3), then it is critically important to acidify your sparging water and neutralize that excess alkalinity. Failing to neutralize that alkalinity is likely to create flaws in your beer.

 

[Fore]

The only acid that will precipitate calcium is phosphoric acid and that reaction will only occur if the calcium content is already high.

Thanks for the info, it really helps cement my thoughts. Having read up further, I had already come to this conclusion, but it wasn't written as clear as this anywhere else, so I didn't feel I could be absolutely sure, but I am now.

I do use phosphoric, and I did see other reports of calcium precipitating, but that was in cases of high reported calcium. In my case I have quite unusual water, in that my calcium is quite low, 35 ppm, and the alkalinity is quite high, 250 ppm as CaCo3. So in my own mash I have used quite a lot of phosphoric acid, 4.5 ml in ~12l, but I suffer no calcium loss at all, as my calcium is already low. In any case I did add calcium to reach a reasonable ~60 ppm.

It starts to become somewhat clear this very difficult subject of water treatment. But I know I'm still only scratching the surface. I read the earlier offered links about pH and I understood about 60% :?. Still, it won't stop me making great beer.

Given the levels of phosphoric acid I add, I do wonder about taste threshold. I know phosphoric is on the low end of taste impact, but how much is too much?