Question regarding bru'n water and reducing mash pH

[olotti]

So I just broke into using bru'n water tonight, plugged in my next grain bill and just tried to figure it out. I skipped water profile and sparge acidification since I'm using all RO water. First question I got my mash pH to 5.3 but it has me adding minerals to not only the mash but the sparge also. I was under the impression from advice received here that one doesn't need to add minerals to RO water, so is this necessary.

Second question. I plugged in a second grain bill , just marris otter and flaked wheat, to mimic an IPA I make. Used the pale ale profile and after adjustment the mash pH was at 5.5. So I added lactic acid until it dropped the pH to 5.2. Is this the correct way to do this?

 

[mabrungard]

You don't have to add minerals to the sparging water. However, you do need to make sure that your sparging water has very low alkalinity (I recommend <25ppm). Since you are using RO water, that should already have very low alkalinity and you can use it as-is. You can add minerals that were calculated for the sparging water, directly to the kettle.

If you actually duplicated all the ion levels of the pale ale profile, I'm surprised that you didn't have a pH lower than 5.5. The high concentrations of Ca and Mg typically drive the pH too low when using RO or distilled water and a teeny bit of baking soda or pickling lime is needed to help keep the pH up around 5.4. By the way, for hoppy beers, targeting a mash pH of around 5.4 helps accentuate the hop and bittering character in the finished beer. No need to target 5.2 in this style.

 

[olotti]

You don't have to add minerals to the sparging water. However, you do need to make sure that your sparging water has very low alkalinity (I recommend <25ppm). Since you are using RO water, that should already have very low alkalinity and you can use it as-is. You can add minerals that were calculated for the sparging water, directly to the kettle.

If you actually duplicated all the ion levels of the pale ale profile, I'm surprised that you didn't have a pH lower than 5.5. The high concentrations of Ca and Mg typically drive the pH too low when using RO or distilled water and a teeny bit of baking soda or pickling lime is needed to help keep the pH up around 5.4. By the way, for hoppy beers, targeting a mash pH of around 5.4 helps accentuate the hop and bittering character in the finished beer. No need to target 5.2 in this style.

So add the sparge minerals during the boil? If so, any certain time? Does it make a difference if they're added at 60 min, 10, 5 or after collecting all my runnings and bringing the wort to a boil?

 

[PlinyTheMiddleAged]

I also use RO water and add minerals. As Martin said, just add your sparge additions directly to your kettle. It doesn't matter when you do it (I do it as I'm bringing my wort to a boil). After the salts have done their job of helping set the pH, they're only there for flavor. So, if you're not using them to help with the pH of the sparge water, then you can add them at any time.

That's my understanding.