Water treatment inPorter brewing

[HomeBrewer14]

There seems to be plenty of information on how to REDUCE carbonates & calcium content in water treatment writings, for the likes of bitters & pale ales, but not so much (if any) on how to INCREASE carbonates & calcium for dark beer (stouts & porters) production. It strikes me that there appears to be some confusion in the writings about raising & lowering mash pH - obviously, to raise (increase) pH, solutions become more alkaline - converseley, to lower (decrease) pH, solutions become more acid. (At least, this is how I understood it when doing A-level Chemisstry, some few years ago)!
I would, therefore, be most grateful to recieve some advice on how to treat 'very soft' water' in order to brew a dark porter (all grain mshh) beer.

[Aleman]

Easiest way is to add some Sodium bicarbonate 1g of sodium bicarbonate per litre of liquor will produce alkalinity equivalent to almost 600mg/l if measured as calcium carbonate. I tend to increase it to a maximum of 125mg/l for stouts, probably a bit less for porters say around 100mg/l (Note the sparge liquor should be low alkalinity for all styles).

You will need to boost calcium as well though and this is where the trick of dissolving chalk in 'carbonated' water comes in handy, but it is a serious faff to achieve, so adding 100ppm calcium to achieve a 1:1 sulphate to chloride ratio is simpler and IMO just as effective.

[Kev888]

Yes, I do very similar to Aleman, which is to use sodium bicarbonate to increase the alkalinity (and then address the calcium, sulphate and chloride levels using calcium sulphate and calcium chloride).

I would suggest measuring the alkalinity before treating, if you aren't already doing so. My supplier's water report is fairly useless in this respect, as the water varies so much sometimes alkalinity has to be reduced, other times increased.

[HomeBrewer14]

Thank you Aleman & Kev888 - I will give it a try. I've had a repy from my water supply company by phne to my written query, & then I checked their wewbsite for an analysis. Both results were fairly similar, but I think I will get hold pf a pH meter

[HomeBrewer14]

Hi again
My water supply is down as 'very soft', the Clarke hardness figure is 2.625, which equates to 37.5 ppm CaCO3, & Calcium comes out at 11.1 ppm. All way too low for a porter/stout, methinks. As I am fairly new at this, am I correct in my assumptiions?

[Kev888]

Hardness and alkalinity are different things, though confusingly they can be expressed in the same units. It is the total alkalinity that you need in this case, not hardness or pH of the water. Even if your supply company quotes alkalinity, for some people it can vary quite a lot from their nominal figures.

Happily, you can measure the alkalinity with a modestly priced kit - the KH/ALC kit from salifert is well respected. The pH meter would still be useful (if it is a reasonable one) but for testing the mash rather than the water or liquor. Get the alkalinity of the mash liquor right for the grain being used and the pH of the mash should fall into line.

[PeeBee]

I was faced with the same conundrum brewing my porter recipe the other month. I also have very soft water.

I think there was a discussion about it here? http://www.thebrewingnetwork.com/post1640/

But whatever, seems Calcium levels for traditional London Porter brewing were high as were chloride levels as Thames water was (is) brackish. So pile in the Calcium Chloride and I used Slaked Lime (Ca(OH)2) to help get the pH right. Using sodium bicarbonate or (god forbid) sodium hydroxide alone tends to get sodium levels approaching "not good" levels.

The link is interesting on another topic. I thought I was being dead clever throwing allsorts at the grain bill to try and emulate traditional "brown malt", but got taught Meantime have been doing it for years. But the Meantime stuff has been throttled back for "modern" tastes (especially hop and smoke levels), leaving it wide open for home brew dabblers.

[Aleman]

Well as only 2g of Sodium carbonate is required to raise alkalinity quite high, it's difficult to see where the definition of 'Not Good' levels of sodium come from ... possibly some US influence here. If high levels of sodium are perceived as an issue then potassium hydrogen carbonate can be used instead ... the malt supplies high levels of potassium so the small qty introduced via water treatment wouldn't be an issue. Slaked lime is normally used (mainly in Germany) to help reduce alkalinity, and while adding hydroxide ions can raise pH (Actually hydroxide ions do contribute to alkalinity), that's not really the purpose, remember that if you get the alkalinity right the pH of the mash falls in the right area, pH of the liquor is irrelevant.

It also tends to be a fallacy that London water is 'brackish' as a lot is drawn from the Lea Navigation, and even historically was taken via wells from subterranean rivers, and not the Thames.

[PeeBee]

Well as only 2g of Sodium carbonate is required to raise alkalinity quite high, it's difficult to see where the definition of 'Not Good' levels of sodium come from ...

Okay, I hold my hands up. I'm a slave to Bru'n Water and I guess I'll take more flak for that? It was getting sodium levels right in Bru'n Water that had me put down "not good" (but I'm aware it's probably a finicky approach, hence the quotes). And Bru'n Water doesn't have an option for potassium hydrogen carbonate, although it is going to be more convenient than slaked lime (pickling lime in US) which you supposed to add to the mash ingredients not directly to the water. Perhaps I should request it as an update for Bru'n Water?

Bru'n Water had my final alkalinity down (for the porter) as 116 ppm "as" CaCO3. Great? One of the advantages of believing what Bru'n Water is telling me is I don't have to worry what "alkalinity" is doing for me.

But all these alkaline salt options we have now is great compared to the old way of adding precipitated chalk (CaCO3) which is about as much use as adding Thames river slime.

[Aleman]

I'm not going to give you flak for using brun'water, but will say that it is based on Kohlbachs research into alkalinity (which was a very limited study in the 1950's) for those reasons being aware of the alkalinity of the liquor, and how the salts contribute to would help brewers understand just WHY they are adding what they are being told to.

As for precipitated chalk, I've managed to get alkalinities in excess of 1000ppm using it (dissolved in water using CO2 under pressure), but it requires time, effort and the right equipment to do.

[PeeBee]

... It also tends to be a fallacy that London water is 'brackish' as a lot is drawn from the Lea Navigation, and even historically was taken via wells from subterranean rivers, and not the Thames.

Can't find what I was reading about London Porter water and Thames water now. I was trying to figure out what might have been going on in the 18th century (when much porter was 100% "brown" malt) - but the Thames will have been pretty polluted even by then. That link (above) doesn't go into it much, just a couple of minutes from 20 minutes in (interview with Meantime head brewer) but that's where the high Calcium and high Chloride levels come from (I barely managed to get 70ppm Calcium but got Chloride up to 85ppm).

The unknown Thames reference went on about there being specific time to extract water based on tides, and that the tidal influx came in as a "wedge" beneath the river water. But it didn't make any difference to how I went about treatment - that was Bru'n Water's "Brown Full" profile with the calcium and chloride bumped up and the apparent bicarbonate bumped up as a result of added enough slaked lime to get a predicted mash pH (not the water pH) below 5.5. This I believe is the right way of going about it - add alkaline salts to get a predicted pH right then monitor the reality to judge changes in future (I'm quite happy with the predictions, so make no changes). Trying to change the pH of an ongoing mash is a route to madness (and I'm quite mad enough thanks).

[PeeBee]

I'm not going to give you flak for using brun'water, but will say that it is based on Kohlbachs research into alkalinity (which was a very limited study in the 1950's) for those reasons being aware of the alkalinity of the liquor, and how the salts contribute to would help brewers understand just WHY they are adding what they are being told to. ...

Sorry for digging this up 6-7 months down the line. But my contributions to this thread seem to be about the same time as my mash pHs all went awry. And I'm faced with the problems faced in the OP. Your ("Aleman") contributions are now taking on a new dimension that I was perhaps ignoring before.

My mash last week was pH5.0, All my mashes in the last six months have been below 5.2. The pH predictions from Bru'n Water now utterly let me down. I've been dropping the figure I used for alkalinity from the paltry 6ppm (as CaCO3) to 2ppm last week and will be zero from here on (fantasy?). I intend to withhold calcium and mangnesium salts (any salts?) until the sparge or beyond as I've learnt that while calcium and magnesium salts are not acidic, they can still depress the pH (I then started following links to "Lewis acids" at which point my brain imploded). Reasonable moves? Should I be doing anything else?

[Aleman]

I think your issue is a lack of calcium rather than reducing your alkalinity, any further than what you have. With an alkalinity of 24 (calcium around 16), I find that I have to add 75mg/L of calcium to get a pH round 5.4-5.5 with a 100% pils malt grist. If I don't do this then my pH can end up around 5.7. If you are then adding 'crystal' malts and/or dark malts then you are depressing the pH further.

For me now would be the ideal time to brew my dark ales as United Utilities have switched to a borehole source and my alkalinity is now up at 147mg/L

[PeeBee]

Calcium. Moot point, 'cos it isn't tested for by our lot (Dwr Cymru), only calculated from the hardness (47ppm hardness as CaCO3, which works out at 19ppm - I calculated 18.8 - calcium). That figure hasn't changed for years, and when I queried about Magnesium ('cos hardness includes it) was told they can't detect any Magnesium. And the published figures pre-date my issue anyway. No alkalinity provided either; the "6ppm" comes from the smallest increment in the Salifert test.

My water treatments usually provide 100-150ppm calcium 'cos you've impressed on me the importance of calcium before. But note I'm finding myself going the wrong way (mash pH <5.2 since last December; 4.9 last week until I cheated a bit - stirring and retesting until it came out 5.0) hence my next step (unless convinced otherwise) will be to hold back calcium additions until after the mash.