Surprise I have a question about a water profile?

[Firestorm159]

I hope that one day I can do more answering questions than I ask questions on this forum but for now I guess I'm mostly stuck with asking questions.
I've been attempting to build my own water profiles with Bru'n water software for about six batches or so using RO water. Anyhow I have a couple questions. I'm getting ready to brew a Scotch Ale so today I was reading over the water knowledge section of Bru'n water about how darker beers tend to produce desirable mash ph between 100-150RA. Well this is something I hadn't thought about with the previous batches that I have done so far. Well
yesterday I sit down and started on the profile. I chose the brown malty profile to follow because I couldn't really find one specific to the style I wanted to use. I added all my minerals to match the profile and ph which wasn't a problem but my ra was -22. OK so if you add enough baking soda to even get close to that it jacks your ph up along with everything else then when you go to add lactic acid to it to drop your ph it tells you not to add both an acid and alkaline to the mash so I was hoping someone might be able to shed some light on this subject for me before I go nuts!

 

[Gavin C]

I've been attempting to build my own water profiles with Bru'n water software for about six batches or so using RO water.

mash ph between 100-150RA. (WRONG UNITS)

my ra was -22. (NO PROBLEM)

OK so if you add enough baking soda to even get close to that it jacks your ph up along with everything else then when you go to add lactic acid to it to drop your ph it tells you not to add both an acid and alkaline to the mash so I was hoping someone might be able to shed some light on this subject for me before I go nuts! {DONT DO THAT]

Ignore residual alkalinity.

Don't add minerals like baking soda to up the alkalinity of the water only to have to add acid to bring the pH back in line.

The HCO3 values in the profiles are just a guide as to what water might be suitable. You don't need any RA. RO water will have none effectively hence the negative value after inputting the grain bill.

In short. Forget all about RA and never try to match HCO3 numbers in a profile.

Cl, SO4, Ca are things to target. (Mg and Na to a much lesser extent)
Then look at pH and add acid to the water/grist meet your target.

It is very rare if ever that adding alkalinity is needed. The exception might be a very dark stout/porter but you could simply mash thinner to produce the desired pH increase. I have never need to add alkalinity.

Best of luck with your brewing.

 

[Firestorm159]

Thanks. The more I read about water Chemistry the more confused I seem to get! O well My beer always taste good to me and everybody else so I must be doing something right. Cheers!

 

[motosapiens]

Thanks. The more I read about water Chemistry the more confused I seem to get!

You and me both, but the more I read here and think about it, the more some things are starting to make sense. I had come to a tentative conclusion pretty much in line with what Gavin C posted, but it's good to see someone more experienced confirm it. The whole concept of residual alkalinity seems like it just gets in the way.

 

[Firestorm159]

I would just love to know how you would achieve an RA of over 100 and maintain everything else? I just don't understand how it is even possible.