RO water treatment question(s)

[butterpants]

This will be my first AG brew. My local water is sucky and inconsistent. I've decided to start with a blank slate and use RO or DI water. Both are available locally and easy to obtain. Slightly worried about the lack of any ions/cofactors in DI so for mash and yeast health am going to try RO for the first batch. After reading Strong's Brewing Better Beer he makes it seem so simple and I'm a pragmatic kind of guy! Now my questions....

The recipie will be the BCS Southern English Brown, scaled up to 10 gallons. (Thread here: https://www.homebrewtalk.com/f12/english-southern-brown-recipie-445399/ ). Definitely a malty and not hoppy beer. Will cold steep for 24 hours the Crystal, Choclate, Carafa Special and short boil (10 min kettle addition). Going off what Gordon says in his book I was thinking of adjusting the brewing liquor by:

+ Adjust mash/sparge water to ph 5.6 @ room temp using phosphoric acid
+ Add 2 teaspoons Calcium Chloride
+ Add 2 teaspoons Calcium Carbonate

Do these salt additions sound reasonable?? I'm certainly not trying to recreate any geographic water profile, just have a healthy mash/ fermentation and accentuate the malt.

I've never used phosphoric acid to adjust the ph of a large quantity of water before, though I am familiar with ph, titrations, etc just on a small scale. For a 10% solution, where should I start (for 12 or 13 gallons of RO brewing water)??

Thanks for the help!

 

[Yooper]

No chalk, at all. It doesn't work, and it's generally not needed anyway.

As far as pH, you want to adjust the mash pH, not the water pH. The sparge water is fine as all RO water.

For additions, you could try using a water spreadsheet (try Brewer's Friend or bru'nwater for free and good spreadsheets) to predict a likely mash pH.

 

[butterpants]

Copy, i'll look for those.

What's the usual ph of RO water? 7?

 

[TopgunTango]

Copy, i'll look for those. What's the usual ph of RO water? 7?

ph 7.

 

[acidrain]

Don't be confused by what the PH of the water is. As soon as you add grain, it will change. Like Yooper said, if you're going to monitor/adjust PH, you do it from at the mash/wort.
If you enter your recipe into the calculators, it will tell you what your expected PH should be, and they are pretty much spot on.

 

[butterpants]

Sparging with ph 7 water kind of flies in the face of everything I've read. Someone care to elaborate?

 

[GotPushrods]

Sparging with ph 7 water kind of flies in the face of everything I've read. Someone care to elaborate?

It's not the pH of the water you add that matters. It's the pH of the resulting solution in the mash.

Since RO water has almost no alkalinity, it has almost no buffering capacity. The mash will bring it right down to it's level.

 

[Piratwolf]

Sparging with ph 7 water kind of flies in the face of everything I've read. Someone care to elaborate?

Actually, I have to agree with this. Thought I listened to John Palmer say you don't want to sparge with water over ph6. EDIT: I'm thinking batch Sparging here. Is there enough left in the mash after 1st runnings to avoid bring the pH down?

 

[acidrain]

Actually, I have to agree with this. Thought I listened to John Palmer say you don't want to sparge with water over ph6. EDIT: I'm thinking batch Sparging here. Is there enough left in the mash after 1st runnings to avoid bring the pH down?

Yes

 

[butterpants]

It's not the pH of the water you add that matters. It's the pH of the resulting solution in the mash.

Since RO water has almost no alkalinity, it has almost no buffering capacity. The mash will bring it right down to it's level.

That actually makes perfect sense, thank you. Oh and yes I'm only really inquiring about batch sparging.