lactic acid question

[repomanz]

Hi folks,

I'm using the ez water calc xls file and i'm curious about the lactic acid addition. According to the spreadsheet, I need to add 5ml lactic acid to bring down my mash ph to 5.6.

From what i've read, 5ml is equivalent to a teaspoon.

Here's my questions (relating to the ez water calc).

1) Do I add the 5ml lactic to my HLT or directly to the mash?
2) If directly to the mash, I assume I do not need to adjust the sparge water (I don't see this adjustment in the xls file)
3) I realize by adding the lactic acid i'm adding a sour flavor to the beer. However is 5ml detectable for a 5.5 gallon batch?

Thanks everyone!

JJ

 

[afr0byte]

If you need 5ml of lactic acid to get down to 5.6, then your water must be rather alkaline. I'd do something to lower the alkalinity before I added acid, if it were me. As far as actually adding the acid--either way should be fine. As far as the sparge water, I'd recommend lowering the alkalinity on that to less than about 50 mg/L as CaCO3.

 

[repomanz]

My water profile:
https://www.homebrewtalk.com/f128/ward-labs-analysis-cedar-park-tx-230802/

If I bought RO water I'd have a starting PH of what? 7?

 

[repomanz]

any other thoughts?

 

[solbes]

It doesn't really matter what you're starting pH is. What matters is how much alkalinity you have to buffer the pH. Less alkalinity means you need less acid to lower the mash pH. And you want the lactic addition to be flavorless, at some point you will be able to notice it. 5 or 6 mL might be on that lower boundary, but I'm not really sure. You certainly want to add some lactic to your sparge as well, I usually add it in the same ratio as the mash (so about 20%).

I have water that is slightly more alkaline than yours, but have quite a bit more hardness too (I have very hard water). So I can get by with diluting my water bill with grocery store RO water ($.39/gallon). Even after diluting 6:1, I have just enough calcium and magnesium to hit my lower targets for light colored beers. I only need about 2.5 mL of 88% lactic to overcome what alkalinity is left. For dark beers I dilute only 3:1 and add similar lactic volumes.