Bru'n water: not sure how to hit water profile for this beer

[apples-to-oranges]

I'm using Bru'n water 3.4 for a robust porter. I'm using the Black Full profile and building my water from RO/deionized water.

I can adjust the salt additions to hit my "Mashing Water Profile" spot on, but need to add some alkalinity (NaHCO3 and Ca(OH)2) to get my pH to the proper range. Since it's not good to add alkalinity to the sparge water (Bru'n water doesn't even allow it), the "Overall Finished Water Profile" ends up being low on sodium and calcium. I've included a screenshot to show what I mean.

Is there any way to compensate for this? Should I try to hit my mash water profile as close as I can and not worry about the overall finished water? Or try to hit the overall finished water, and my mash pH, and not worry about hitting the other values for the mash water profile?

 

[The_Bishop]

I wouldn't get so caught up with hitting every number exactly on the button, especially sodium. As long as your calcium is around 50ppm, you'll be fine there, too.

Personally, I'd drop the epsom salt and replace the resulting missing sulfate with gypsum to get the calcium up.

Get as close as you can and make sure your mash PH is right, and you're mostly there.

 

[mabrungard]

You don't really need 50 ppm Ca in your water to brew effectively. As long as you have about 40 ppm Ca in the mash, that will drop oxalate. The malt itself contributes Ca to the wort and that is sufficient for yeast function. However, you do want 50 ppm Ca in ales to help clear the beer more quickly. But its not imperative.

 

[The_Bishop]

Learn something new every day, I guess. I always thought the magic number for oxalate was 50 ppm.

 

[mabrungard]

50 ppm Ca is certainly safe in assuring oxalate precipitation, but my anecdotal evidence suggests that 40 ppm Ca in the mash tun is sufficient. Take that with a grain of salt, since that is about all it is based on.