Follow up water chemistry questions

[Kent]

Hi All,

Thank you for your help with water chemistry. I am using a combination of reverse osmosis water along with my local well water to create appropriate water electrolyte concentrations for my all grain brews.

The question I have is "what would my RO water alkalinity (CaC03 ppm) be? Would you call this zero because the calcium has been removed by the RO process? Any thoughts?

As a second question, I have been treating my RO water just like distilled water and am assuming it is ion free. Do you think that is a fairly accurate assumption in general? I certainly could have it tested.

Lastly, my water is hard, alkaline, and I am brewing a lightly colored IPA. My brewers friend water analysis calculator recommends phosphoric acid 10% additions to the mash and sparge water to achieve a ph of 5.4. Volumes recommended were 40 cc and 25 cc respectively. That seems like a whole lot of acid to me. Does this sound like it is in the ballpark. I will measure Ph as we go, but just want an opinion from amore experienced brewers.

appreciated,

thanks
Kent

[jimrmaine]

RO water is not quite the same as distilled, but close enough to zeros across the board.
I can’t answer the phosphoric acid Q. I use lactic acid when Brun water says I should. It’s usually in the 3ml range. But, I would trust what Brewer’s friend tells you.

[brewdvm]

The phosphoric acid additions could be correct for hard water and a light colored beer. Are you factoring in the fact that you’re diluting this water with RO water in your phosphoric acid addition calculations?

[dmtaylo2]

I think you are totally on the right track. For RO water, I would assume zeros for all ions. It’s not exact but it is definitely close to zero.

And yes, you probably need to use that much 10% phosphoric.

[sneezles61]

So, I have to say, before you do your water adjustments, do check your water pH. How would I know? I used my usual acid correction, and before I add grains, I do check. Went way too low… This isn’t the first time either… So I had enough of this… I checked my plain old water pH… 7… When I had my water tested it was 8.1… So to you peeps that brew with a online water calculator… You best check your pH to see if it has changed… You can’t take for granted its always constant… Sneezles61