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.

Kal

I recently saw the following on another brew site:

http://www.probrewer.com/vbulletin/archive/index.php/t-6245.html
"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.

Mark
Hidden Well Brewery (site below)
http://www.makewebs.com

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.

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?

Found it:

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

Here at the bottom

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!

Kal

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.

Zen_Brew said:

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.

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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
Kal

Brew Strong

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.

"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."
Go to braukaiser.com

Zen_Brew said:

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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Good reminder! The one I use from Morebeer.com is temp compensated from 32-140F: http://morebeer.com/view_product/18707//pH_Meter_-_Phep_5

Kal

You can taste lactic acid at relatively modest concentrations, the question is, is the taste a bad thing? Get a pipette (or a syringe and make a diluted working solution) and play around with adding various amounts to finished beer. This will inform you about where your flavor threshold for lactic is and what a beer with some lactic flavor, which is not sour, tastes like.

It takes quite a bit to make the beer actually sour, you won't make the beer sour by adjusting your mash pH to a normal level.

hmm, digging up an old thread here, but can anyone comment on experience using lactic acid to the point where they could taste it? we brewed a brown tonight, and added 9ml to 7.5 gallons of mash (biab) to bring the ph down to a good level. this was for a 5 gallon batch. was it too much?

If you read back in this thread the general consensus is that adding more than 2ml of lactic acid (88%) per gallon may be detected. Of course that will depend on the beer being made and your general sensitivity to these things.

So for 7.5 gallons that would be 15ml instead of the 9ml you added. Will you notice 9ml? I don't know.

That said, 9ml in a brown (which I'm assuming has plenty of darker malts) seems like an aweful lot to have to bring the pH down. What's was the grain bill? What kind of water? What were you measuring pH with? At what temp?

Kal

ok, i wasnt sure if there were current different opinions on the 2ml of lactic acid per gallon. it did seem like an aweful lot to add, and caught me off guard. this brew was done with the biab method, so all 7.5 gallons were treated with the grains in. we used distilled water, with .75 gallons of my tap water. we also added 3 grams of gypsum, and 3 grams of calcium chloride.

our ph meter is a ysi ecosense ph10, 3 point calbirated and checked before brewing. i am nearly positive our meter was reading right. when i take a sample, i cool it down by running cool water on the outside of the container, and then taking a reading. temp of sample was around 23c. however, i wish i would have tossed in a ph strip just for good measure, but i didnt.



mash schedule
@15 minutes ph was 5.8
@20 minutes ph was 5.7 add 3ml lactic acid
@30 minutes ph was 5.7, add 3ml lactic acid
@35 minutes ph was 5.5 add 3ml lactic acid
@45 minutes ph was 5.3

the beer was a caribou slobber american brown from northern brewer

9 lbs rahr 2 row pale
.75 lbs briess caramel 60l
.5 lbs briess caramel 80l
.25 lbs fawcett pale chocolate
.125 lbs english black malt

IMHO, it doesn't make any sense that you'd need any lactic with a recipe like this when using mostly distilled water.

Distilled water has a PH of 7, I don't know what your tap water's like but you didn't add much so the total water is likely close to distilled.

Gypsum and Calc Chloride both lower pH.

When I punch these into EZ water 3 the estimated room temp pH is 5.5 which is exactly in between the 5.4-5.6 desired room temp mash pH.

My guess is that something's wrong with the way it was measured.

Kal

Agreed, sounds like a lot of Lactic for that recipe.

I have pretty alkaline water, so I use a combination of Reverse Osmosis water dilution (40-80% RO) and lactic addition to bring my pH to 5.5. For really light pilsners and Kolsch, I add up to 2 or 3 mL, for darker beers I add 0-1 mL. This into 5 gallons of wort. A little lactic can go a long way.

I haven't been able to taste it at all with these low concentrations.

i am not sure, maybe it is my ph meter. i just fired it up and stuck it in some 4 buffer, it was reading 4.54, with 7 buffer it was reading 7.66. it was reading buffers correctly before we mashed in yesterday, so not sure if its the meter or not. calibrated the meter again this morning, (3 point) and double checked all the buffers to make sure it was reading correctly, and it was. i have a bit of the post boil wort that has been sitting on the counter over night, and it is reading a ph of 5.00. ph strips are telling me 5 also. will boiled wort drop or increase in ph vs mashed ph readings?

another question: my ph meter has temp correction built in. what ph should i be shooting for? i see people shooting for a different ph at mash temp vs room temp. i have never stuck this ph meter into 150f water, and do not care to for the sake of finding out. will the temp correction on the meter read the ph the same at 150 vs room temp, or is it actually the mash itself that is changing in ph with a temp drop?

well, after doing some research, i guess it IS the mash that actually changes in ph with temperature, not a function of the ph meter. wish i knew that a week or two ago! so, this should be what to aim for, correct?

Measuring pH at mash temperature (lets say 65°C)

Target: 5.2-5.4 Acceptable +/- 0.1

Measuring pH at room temperature (lets say 21°C)

Target: 5.4 - 5.6 Acceptable +/- 0.1

kind of a bummer to find this out now, we brewed our last three batches shooting for a mash ph of 5.2-5.3 at room temp. i just assumed the reason people were adjusting for temperature was because of their meters not adjusting for it. should have done a bit more reading, live and learn, just hope the beers dont turn out undrinkable!

The good thing Veedo is that 5.2 is a balance. For some things the ideal range is higher, for some the range lower. 5.2 is just the happy mid-point of balance in these things so if you went a little low you are still good and no one tasting your beer will ever know.

A few things to comment on re this thread:
1. The real pH of mash (and most buffer systems) changes with temperature. With mash it shifts down as temperature goes up. The usually stated number of 0.3 between mash and room temperature is higher than what is usually observed. Also "mash temperature" could be the temperature for a beta glucan rest (105 °F), for a protein rest (122 - 128 °F) or a saccharification rest (142 F - 157 °F). Obviously, the shift RE room temperature will depend on which. ATC in a pH meter does not correct for this effect.
2. The response of a pH electrode depends directly on the temperature:
E = E0 + R*T*(pH-pHi)
where T is the tempearture (in Kelvins). It is the job of ATC to compensate for this effect.
3. pHi (the isoelectric pH) is assumed to be 7. If it isn't ATC will lead you astray rather than help you. While larfe error in pHi isn't usual it is safest to measure buffers and sample at as close to the same temperature as possible. As high temperatures stress pH electrodes it is good to have this be close to room temperature.
4. There are lots of opinions as to what the ideal pH range is. Mine is that it is 5.4 - 5.6 at room temperature.
5. Most beers, including some pretty dark ones, will require some form of acid to be added to the mash to get pH into this range.
6. Acid (or alkali) added to mash must be mixed in very thoroughly and some time must be given for it to react before a new pH reading is taken.
7. pH meters can be quirky. With experience you will learn when to be suspicious. If suspicious to a calibration check with 4 and 7 buffers.
8. Three point calibration is not necessary for brewing. pH 4 and pH 7 buffers are plenty. If you are measuring outside 4 < pH < 7 then a 10 buffer calibration point is advisable.
9. Buffers should be freshly prepared. This is especially true of 10 buffer which will pick up CO2 from the air.
10. The pH of distilled water will be less than 7 (also because of pickup of CO2 from the air).
11. The pH of the mash water has little to do with the pH of the mash. The alkalinity and hardness of the mash water do.

ajdelange said:

The usually stated number of 0.3 between mash and room temperature is higher than what is usually observed.

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thanks for the replies guys. aj, could you explain this part a little better? i guess from now on i will shoot for 5.4-5.6 at room temp to make it easy. also, do you have any personal experience on when you will begin to tase lactic acid?

one more question, will ph drop in wort that has been boiled, and if so, about how much? if i knew that, i could somewhat confirm where my ph was on the last brew day. i have a sample on the counter that is reading 5.0.

Veedo said:

aj, could you explain this part a little better?

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It's probably obvious that the shift is going to depend on the nature of the buffering i.e. how much comes from phosphate, how much from carbonate, how much from which residue on what amino acid, mash thickness and probably the Nile flood stage. I am not willing to sacrifice a pH electrode for a full run from room to mash but I have gone up in temp enough to measure the slope near room temperature. It was about 0.0055 pH per °C. Assuming that the response stays linear at the higher temperatures this would amount to an 0.24 pH shift from room temp to 150 °F and 0.17 from room to 125 °F.

Veedo said:

...do you have any personal experience on when you will begin to tase lactic acid?

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I would only tase it if it got totally out of hand (sorry - I just had to). I don't use lactic acid. I use sauermalz. I have never used it at above the 3% of grist level and you do taste it there but it does not taste sour. It, to quote the Weyermann website "adds subtle complexity to the beer" and those are better words than I could come up with. I, obviously, consider this a definite benefit or I wouldn't use the stuff.

Veedo said:

one more question, will ph drop in wort that has been boiled, and if so, about how much? if i knew that, i could somewhat confirm where my ph was on the last brew day. i have a sample on the counter that is reading 5.0.

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That again depends on a lot of things. I'd guess that 0.1 - 0.2 would be typical. Some brewers add acid and/or salts to the wort to insure this.