Water Adjustment - Which tool to trust?

[bwarbiany]

So, I've been on RO+additions for quite some time now, using Bru'n'Water.

It basically is constant telling me I need to add ~1.2 mL lactic acid to the mash and 0.1 mL to the sparge, pretty much no matter what inputs I put into the spreadsheet. I've seen a few as low as 1.0, and as high as 1.4, but all in that range.

Yet I remember Nixon posting previously about a different water calculator that called out needing basically 3x the amount of lactic acid. And I got into a discussion on HBT asking about this very discrepancy and heard that Bru'n'Water routinely overestimates the mash acidification of malt, giving estimates too low of the amount of lactic acid needed.

So I'm wondering what you guys usually recommend? Overall I've been happy with Bru'n'water, but this particular discrepancy has me a bit concerned.

[brahn]

And I got into a discussion on HBT

That's never a good idea.

If you've been happy with Bru'n'Water, stick with it. If you're unsure and want to be sure, get a pH meter and check your mash pH.

[bwarbiany]

And I got into a discussion on HBT

That's never a good idea.

If you've been happy with Bru'n'Water, stick with it. If you're unsure and want to be sure, get a pH meter and check your mash pH.

I have a pH meter, but no calibrating solution and I've never used the meter... I suppose maybe I should figure it out rather than let it gather dust.

I'm happy with Bru'n'water for mineral additions. I find it really easy to use. But if the acid additions are routinely off by a factor of 3, it would be good to know.

[BrewMasterBrad]

I'm still using Bru'n Water. I have had no issues and my pH readings have been as predicted in the tool. If something looks crazy in Bru'n Water when I'm formulating a new recipe, I will use EZ Water as a sanity check.

[bwarbiany]

I'm still using Bru'n Water. I have had no issues and my pH readings have been as predicted in the tool. If something looks crazy in Bru'n Water when I'm formulating a new recipe, I will use EZ Water as a sanity check.

How much lactic acid are you typically adding?

[BrewMasterBrad]

How much lactic acid are you typically adding?

Well, that depends. For a light lager where there is little acidity added to the mash from the grain bill, I am adding about 42ml of 10% Phosphoric acid to the mash of 7 gallons of water and 16 pounds of grain.

For Traditional Bock, I am not adding any acid. The grain and the mineral additions are enough to get me to my target pH.

[bwarbiany]

How much lactic acid are you typically adding?

Well, that depends. For a light lager where there is little acidity added to the mash from the grain bill, I am adding about 42ml of 10% Phosphoric acid to the mash of 7 gallons of water and 16 pounds of grain.

For Traditional Bock, I am not adding any acid. The grain and the mineral additions are enough to get me to my target pH.

How do you arrive at that number? 42 mL of 10% acid would be closer to the 4-4.5 mL of 88% lactic acid number (I looked at this a little closer and it's not a direct proportionate relationship as I understand it, but close enough for this discussion). That's 3x what I'd use, as suggested by Bru'nWater, for a pale beer.

[bwarbiany]

tl;dr -- I'm an idiot.

Turns out I wasn't using Bru'n'Water correctly at all. I thought it was calculating acid additions for me, not expecting me to calculate them myself. And I didn't see on the "Adjustment Summary" their predicted mash pH, so I didn't address this problem.

I most likely have been running with a slightly high mash pH this whole time... Which is good that I figured this out since my next beer will be a pilsner with 2L malt, so I've properly calculated my acid addition and the spreadsheet says I need ~6 mL of lactic acid to get a mash pH of 5.3.