Low Alkalinity Water and High Mash pH

[Matt12398]

I asked some questions on this not so long ago but I'm still not entirely sure.

I have very soft water with very low alkalinity. I put an all pale malt recipe into Bru'n Water and the predicted mash pH is 5.6 if I adjust in line with the yellow and balanced profile. I know it's only a prediction but regardless of the profile though I thought I'd get a slightly lower pH with my water.

Ignoring that for the minute, I'm thinking about how to bring it down to around 5.3. I have phosphoric acid but ideally I want to heat all of my liqour together and was only intending to add acid for the purposes of reducing the pH of the mash rather than reducing the carbonate. Has anyone got any suggestions?

[Dave S]

You can add Calcium Sulphate and/ or Calcium Chloride to further lower the pH. If you've got very low alkalinity you probably don't need to add acid at all. I did a brew at a friend's house recently where the water has low alkalinity and only a very small amount of phosphoric was needed in the sparge water - probably could have got away with none at all. All of the pH adjustment was done with gypsum.

[Matt12398]

My observations are tied to Martin's water profiles. It's an exmoor gold clone which isn't super hoppy so I went with yellow and balanced. If I followed the pale ale profile it's a lot lower and in the range of what I wanted. I know these profiles are just guides but I didn't know how that much gypsum would after the taste when it wasn't a hop forward beer like an IPA is.

[Dave S]

My observations are tied to Martin's water profiles. It's an exmoor gold clone which isn't super hoppy so I went with yellow and balanced. If I followed the pale ale profile it's a lot lower and in the range of what I wanted. I know these profiles are just guides but I didn't know how that much gypsum would after the taste when it wasn't a hop forward beer like an IPA is.

I believe that's where you would use calcium chloride, which brings forward the malt profile. My tap water is high in chlorides, so I rarely use it.

[mabrungard]

Your result of a 5.6 pH with all pale malt in your low alkalinity water is not a surprise. Kohlbach's results for all Pils malt in distilled water is somewhere between 5.7 and 5.8.

For an ale, increasing the calcium content to at least 50 ppm will improve the yeast performance and clearing. Adding a calcium salt has the added benefit of reducing mash pH through its interaction with phytin. You could add a bunch of calcium to the mashing water and achieve a desirable pH. However, using an acid is more expedient and its less likely to create a minerally taste due to the high calcium salt addition. Phosphoric is a good, neutral tasting acid. With a low alkalinity water, you would not have to add much of any acid and the potential for a taste effect is very small.

[Matt12398]

Thanks Martin. Would you treat the whole liqour with acid or just the mash liqour? Ideally I wanted to heat it all together.

[mabrungard]

If the water already has low alkalinity, say less than 25 ppm as CaCO3, then its not necessary to acidify the sparging water. But its also not a problem to do so anyhow. Do be careful of adding too much acid and ending up with a tart beer.

[Aleman]

I will disagree with Martin, Once you have adjusted the alkalinity of your sparge liquor to that required for your beer style, do you actually need to add more acid to bring the pH below 6.0?? If you really are determined to sparge way below 1.012 then ask yourself what it is you are extracting. . . . Yes your efficiency will be way up there in the 90's but does that create good beer . . . I maintain not, and that it is much more beneficial to throw in another 500g of base malt and stop sparging when you have collected enough 'sugar' to hit the desired OG following the boil. Doing this ensures that you will stop sparging at a much higher gravity, and therefore a much higher pH, which avoids completely the necessity of adding acid to chive the same thing.

The question is actually raised Here

[Matt12398]

For me it's not about lowering the pH for the sparge it's just to get the mash pH right. I don't want to have to heat two separate batches of water though. I want to heat all the liqour in one go. That makes it very difficult to treat the mash liqour seperately so was just wondering what the effects would be of treating all the liqour with acid when I only want to treat the mash liqour:

[Aleman]

Hi Matt,

Technically speaking you should treat all the liquor with acid as it all needs to be the alkalinity required for your beer style. Once you have the alkalinity in the right ball park for style then the roast malts and 'flavour' salts will serve to bring the mash pH down to where you want it.

I add the mash salts to the grist before mashing in, and I also add some salts to the boiler just before running off . . . so the only treatment my liquor gets is that for alkalinity adjustment.

[Matt12398]

Thanks Aleman. Yes I get that but my alkalinity is low enough already. I have the British equivalent of Pilsen water. So for me the acid addition is about reducing the mash pH to within an acceptable range for an all pale recipe, not because of the alkalinity present in my water.

[Aleman]

That's you and me too with the Plzen water

I find hitting the mash pH is never really an issue with most beers, it becomes more of an issue with a lot of dark malts as we have to increase the alkalinity. I've certainly found there is no need to acidify the liquor even with under modified pilsner malt. Rather than using acids just the calcium salts get the pH where I want it to be . . . I normally aim for an addition of 100ppm calcium with my pale beers using sulphate or chloride depending on style and what I want the flavour profile to be.

[mysterio]

What pale malt are you using? I've noticed a 0.1 difference between Halcyon and 2-Row, for instance.

Do you have a pH meter or alkalinity meter? I would hold off treating with acid until you can do this.

[Matt12398]

Thanks Aleman. If I go for a large addition of Calcium salts I can get it exactly where I want but I wasn't sure I'd want to do that for all beers.

Mysterio, this time it was MO. I have a pH meter. I don't have an alkalinity meter but I do have a water analysis from Murphys and Sons. I've been using Bru'n Water to work out what salts to add and the predicted pH has always been very close to the actual pH.

[mabrungard]

If all you brew are pale beers. Then treating all your water the same is OK. If you would like to brew great stouts and porters, then you do need to treat the mashing and sparging water differently. Sparging water should always have low alkalinity. Mashing water may not need to have low alkalinity for all brews.