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-   -   How much lactic acid needs to be used before you can taste it? (http://www.homebrewtalk.com/f128/how-much-lactic-acid-needs-used-before-you-can-taste-159703/)

kal 01-28-2010 12:26 AM

How much lactic acid needs to be used before you can taste it?
Hi guys!

The general concensus for lowering sparge water pH is that phosphoric acid is better than lactic acid since it is tasteless. Lactic in large quantities can potentially leave flavor in lighter beers.

Haven't been able to source phosphoric acid (10%) so I bought lactic acid (88%).

So how much lactic acide per gallon is "too much" if making a very light tasting lager? Is there any general guidelines on this?

I'm using it to reduce my ~8 pH sparge water down to ~6.


ipscman 01-29-2010 02:02 AM

Lactic Acid
I recently saw the following on another brew site:

"The generally held information for reduction of pH by Lactic acid is 58 grams of 100% Lactic (Rarely you will find it 100% - more typically it is 85% so adjust accordingly) per 100 Kg malt to reduce pH by 0.1 in Mash and 29 grams in the Kettle. Other information is given in Stephen Holle's (MBAA) book 'Handbook of Basic Brewing Calculations'. "

By my calculations using the above I came up with the following for homebrewer volumes:

At 88% solution need .09036 gm lactiic acid per lb of grain to drop pH by 0.1.

I tried this a week ago with a Belgian Golden Strong and following these calculations it did reduce the mash pH from 5.5 to 5.4 in a couple of minutes time.

I recently purchased a used copy of Stephen Holle's (MBAA) book "Handbook of Basic Brewing Calculations" for $20. When it arrives I will see what additional information is included on this subject and pass it on.

There is an argument against using phosphoric acid, BTW:
1. Palmer (How to Brew, p. 164) says, "Phosphoric acid is not recommended, because it reacts chemically with calcium in the mash and changes the whole playing field, rather than simply adjusting the pH."

Regarding flavor effect,
2. DeClerck (Textbook of Brewing, vol. 1, p. 328) says, "The following acids are used for acidification: sulfuric acid, which gives beer a dry palate, or hydrocloric or lactic acids which give beers with fuller palates." The above is quoted without attribution virtually verbatim in Goldammer (The Brewer'sHandbook, p. 158) and The Practical Brewer, p. 118 (1977 ed).

Fix (Principles of Brewing Science, p. 11) has a chart comparing acid treatment of water using lactic, phosphoric and sulfuric acid. He offers specific amounts for each based upon the alkalinity of the base liquor and moving to a pH of either 5.5, 6.0 or 6.5. Using 6.0 as your target, and 50% lactic acid (only amount listed), Fix recommends at 100 aalkalinity 22 g/Hl; at 200 alkalinity 50 g/Hl, and at 300 alkalinity 73 g/Hl.

Hardwick (Handbook of Brewing, p. 148) suggests 72 g p/100 kg of malt if using 80% lactic acid, to change the pH by 0.1.

Hope this helps.

Hidden Well Brewery (site below)

Zen_Brew 01-29-2010 02:15 AM

This topic is coverred on the 4 part Waterganza podcast on brew network with Jamil and John Palmer. It's a good listen albeit a bit long with 4 episodes at about 1 hour each.

I believe Palmer says for lactic acid anything over 2 mL/gallon will begin to add a flavor component.

Palmer also says Phosphoric acid will precipitate calcium out of solution, so it can throw other things out of whack there.

dstar26t 01-29-2010 12:18 PM

So, if 2 mL/gal is the upper limit for adding a flavor component, and .295 grams/lb of grain in the mash will lower pH by .1, how many grams of lactic acid (88%) are in one mL?

dstar26t 01-29-2010 01:57 PM

Found it:

"88% lactic acid, for example, weighs about 1214 mg/mL"

Here at the bottom

kal 01-29-2010 05:27 PM

Cool guys. Thanks. Wow - Talk about concise info!

I need to go back and re-read Palmer's book (I have it) on this subject like you stated Mark. I wasn't aware that phoshoric would throw out calcium. I do adjust my water using TH's spreadsheet and certainly don't want to do that!

My only reason for wanting to use lactic acid is because (a) even with calcium and other additions in my mash, my pH isn't quite low enough and I don't want to add more minerals, and (b) for sparging to reduce the sparge water down to about 6 pH (from around 8). If I don't do this my pH does creep up past ~6 near the end of the sparge. Haven't tasted any tannic tastes yet but figured it's better to be safe then sorry.

@Zen_Brew: 2ml of Lactic acid (at I presume 88%) per gallon of water is pretty high. I only added about 4ml total in 13 gallons of water to get the pH from 8 -> 6. I'd say I'm safe! I'll certainly give those Waterganza podcasts a listen. Thanks for the heads up!


Bensiff 01-29-2010 05:36 PM

Perfect guys, I was just trying to figure this out as I am brewing a 4.2L Beglian Golden Strong and my ph meter is 6.8 and I wanted to get the sparge water down to 6. I couldn't remember how much JZ said could be added before the taste threshold on that 4 part series, so all around great info guys. Couldn't be better timing as I will be done mashing in about 30 minutes...back to the garage...

Just added some 88%. It took 2ml to lower 7.5 gallons from 6.8 to 5.9/6.0 range FYI, a little goes a long ways as Kal said.

kal 01-29-2010 07:55 PM


Originally Posted by Zen_Brew (Post 1845710)
This topic is coverred on the 4 part Waterganza podcast on brew network with Jamil and John Palmer. It's a good listen albeit a bit long with 4 episodes at about 1 hour each.

Do have links to these 4 parts at http://thebrewingnetwork.com/ ?
I'm coming up completely blank searching for "Waterganza". Is it part of the "Sunday Session"? What dates?

EDIT - Oops - never mind. They're here:

Part 1: Brew Strong: Why Adjust Your Water http://thebrewingnetwork.com/shows/497
Part 2: Brew Strong: Water II - How to Adjust Your Water http://thebrewingnetwork.com/shows/500
Part 3: Brew Strong: Water III - Adjusting Water to Styles http://thebrewingnetwork.com/shows/508
Part 4: http://thebrewingnetwork.com/shows/513 http://thebrewingnetwork.com/shows/513

dstar26t 01-29-2010 07:59 PM

Brew Strong

Zen_Brew 01-30-2010 12:57 AM

Yeah sorry. I think the BN guys refere to the series as the waterganza shows although that name does not appear in the title links to the shows. I just have heard them call it waterganza so much, I picked up the term.

Nice work on the ml to grams conversion dstar.

One last thought. Remember when measuring PH, with rare exception you will be performing the measurement near room temp and there is a correction for PH at mash temp. I believe the rough correction is subtract 0.3PH from your room temp reading.

I used to make the mistake of thinking if you used test strips you were dipping them in the wort at mash temp, but in reality as soon as you remove the strip to read it, the strip rapidly cools to room temp as it is a very small volume of wort on the strip and will not hold the temp once removed from the wort.

Some high end PH meters will take a reading at 150 degrees, but not many of them.

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