Residual Alkalinity question

[Chris Z]

I have very hard water with a pretty high residual alkalinity... 265. I'm brewing a stout, so a higher RA should work. 265 if pretty high though...Off the charts of what I've seen. How crucial is it that I get the RA in the range of say Dublin's water near 125?

Do I need to be more concerned with RA or Ph? or both?

I'm not trying to build or mimic a certain water, just making sure it will "work"
Using the Bru n Water spreadsheet it seems that if I add acid it lowers the RA and the Ph, but if I just add acidulated malt only the ph is lowered.

what do you think?

 

[Homercidal]

Well, I would not use RA as a consideration when making up my water. I'd target a mash and sparge pH that was appropriate for the style and the RA be damned.

 

[Tiber_Brew]

I'll try to address each of your questions individually.

I have very hard water with a pretty high residual alkalinity... 265. I'm brewing a stout, so a higher RA should work. 265 if pretty high though...Off the charts of what I've seen. How crucial is it that I get the RA in the range of say Dublin's water near 125?

It isn't necessarily ideal to target any city's water profile. First, most large breweries adjust their water prior to brewing. And really, water is an ingredient just like malts or hops. Experiment a bit with water adjustments to see what you prefer yourself.

Do I need to be more concerned with RA or Ph? or both?

The main difference between RA and pH is kind of like this: residual alkalinity is relative, and potential Hydrogen is absolute. They both matter, but you as a brewer are focused more on the pH of your mash, not necessarily the pH of your water. Since your malt bills will change with each style, the RA will vary and you need to focus on the final result of your adjustments more than the pH of your water.

I'm not trying to build or mimic a certain water, just making sure it will "work"
Using the Bru n Water spreadsheet it seems that if I add acid it lowers the RA and the Ph, but if I just add acidulated malt only the ph is lowered.

what do you think?

I'm sure your beer will "work," but the most valuable outcome from it will be an observed datapoint. If you can accurately measure your mash pH, then you can compare the results to the spreadsheet and adjust accordingly. Acidulated malt is just sprayed with lactic acid, so essentially it accomplishes the same result as adding lactic acid to your mash.

Hope this helps. I'm sure someone who knows more will chime in.

 

[ajdelange]

Brewers would be well to use RA for what it was intended for - comparing water supplies. OP RA number of 265 is indeed off the chart and should give some indication as to the suitability of the water for brewing. Does not look good based on RA alone.

RA by itself doesn't tell us much more than that the water of one source sort of resembles the water of another with similar RA. It compresses two degrees of freedom into 1. We really need information about the alkalinity and hardness of the water (the two things from which RA is computed) to understand it. An RA of 265 implies that the alkalinity is at least that high and if the water is hard, even more alkaline than that. This, again, says the same thing. That alkalinity will have to be dealt with. If you have a lot of hardness (which would result in a smaller RA) then there is the possibility of using it to remove bicarbonate. Given OP's high RA this doesn't look like a possibility.

In planning a beer you need worry neither about RA nor pH. The alkalinity is the main concern but pH is a minor factor if pH is unusually high or low. Otherwise, alkalinity tells most of the story. Nor should OP worry about whether his water hits a particular level of salt concentration associated with a particular city as that information is often not accurate nor does it give any indication as to what the brewery did to make whatever water it had useable for the beers it brewed.

For this water it looks as if the only treatment is throwing it out and replacing with RO water (or diluting the source water with so much tap water that it amounts to the same thing). It would help to see the actual water report numbers, however.

 

[Chris Z]

ok,

ph 7.6
TDS 474
cations/anions 9.2/9.5

sodium 1
potasium 1
calcium 90
Magnesium 52
total hardness 442
nitrite 1.7
sulfate 15
chloride 46
carbonate <1
bicarbonate 435
total alkalinity 365

when I entered the numbers in the spreadsheet (Bru 'n Water) my understanding is that most of the values are ok. Looks to me like adding a little acid made it all work.

 

[ajdelange]

You have 7.3 (= 365/50) mVal of alkalinity. That is an awful lot. You also have 90/20 = 4.5 mVal of calcium hardness and 52/12.15 = 4.3 mVal magnesium hardness. You can, as is, drop those down to about 1 mVal calcium hardness i.e. by 3.5 mVal which will also drop 3.5 mVal of alkalinity getting you down to 3.8 by boiling/lime treatment. That's still an awful lot. You can also add more calcium in the form of sulfate, as the chloride is already appreciable, and get more of the alkalinity out but all these processes are a bit hairy relative to the extremely simple expedient of using RO water. You can work with this water but it is more trouble than it is worth as it will require the advice of an expert and some experimentation.

 

[Chris Z]

That sounds a little more technical and involved than just adding a little acid and calling it good. It is also a bit above my knowledge and understanding of the chemistry involved in brewing beer.

I do have before me an opportunity. . . Last weekend I brewed a milk stout using my water and just added a little acid. This weekend I'll try to brew the same thing, with ro water built up to fit the style... then see if I can taste the difference.

thank you

cz

 

[ajdelange]

That sounds a little more technical and involved than just adding a little acid and calling it good.

It is. That's why most people in your position would go to RO water. You don't have to add a 'little' acid. You have to add a lot: about 5.8 mEq/L. That will 0 the alkalinity (WRT mash pH) but will leave 5.8 mEq/L of the anion of whatever acid you chose and that's quite a bit. If you want to use this approach choose phosphoric as it is the more flavor neutral.

It is also a bit above my knowledge and understanding of the chemistry involved in brewing beer.

Granted and again that is why most folks would abandon this water in favor or RO if that is at all feasible for them. With RO the KISS principle of the Primer can be applied and you don't even have to know how to calculate the acid addition.

 

[Chris Z]

I recently brewed a few different batches of the same brew (a milk stout). I used MY water and calculated acid additions based on the Brew'n Water page. My mashing seemed to go a lot better, my efficiency went from near 65% to 80%. Which I believe is a result of finally having the mash ph in the range it needs to be.
Another issue I still have. . .my fermentation still is stopping at 1.035, I was hoping for somewhere closer to 1.020. This was on several batches, i do not believe it is was isolated, this is the issue that I've been struggling with for some time and has led me to looking into water in the first place.
With some of the ion ratios cited earlier, is that the reason for incomplete fermentation, or perhaps its actual mash ph? I've only used "calculated" mash ph.
any thoughts...?

cz

 

[Homercidal]

Odd. Good conversion and proper mash temp ought to help a lot with stuck fermentation. You might look at fermentation temps. Sometimes I raise mine up near the end if it seems to stay a little high. But that is only if you are pushing the lower limits for the yeast. If you pitch enough healthy yeast, give it the right food supply, and good conditions (pH, temperature, etc.) they should normally get down in the proper range for the average beer.

 

[mabrungard]

+1 to raising fermentation temp when fermentation slows. Some yeast can drop out early if the temp is low. We often target temps that are good for beer flavor but poor for fermentation. Raising the temp at the end is a good compromise.

Are you pitching enough yeast? The water quality you cite is not bad for an ale yeast.

 

[Chris Z]

I'm glad I checked a few things before responding...My fermentation area is much colder than thought. I'm pretty sure that is the problem this time. I pitched on 1/2 a yeast cake for the last two so I think they started with enough yeast.

Thank you

cz