Using lactic acid to reduce mash pH, how to use correctly?

[thehopbandit]

I've done a number of All Grain brews, but have never bothered to mess with the water chemistry. However, the next beer I'm doing is a huge beer with a ton of Pilsner / Pilsen malt. According to Beer Smith, my estimated (calculated) mash pH is up around 5.69 which is far too high. I'd like it to be <5.4. Shooting for a 10 gallon batch.

Using the mash adjust tool in BeerSmith, it calculates ~18.1ml of 88% lactic acid to bring the mash pH down from 5.69 -> 5.3. The water I'm starting with has a total alkalinity of 23ppm.

Questions:
- Is this too much lactic for a 10 gallon batch?
- Can I just use the lactic by itself? Am I ok to simply add the calculated amount of lactic to the mash water without adding any other salts?
- I'm slightly confused because when typing these numbers, along with the lactic, into calculators like EZ Water and Brewer's Friend, the effective and residual alkalinity numbers shoot down way into the negative hundreds, like -600. Why is this such a huge negative, is this bad, and what exactly does this mean?
- I'm essentially just looking for instructions on how most simply and effectively I can use lactic to correctly bring down my mash pH.

Thanks.

 

[Kerrbrewer]

That looks high to me. I used to use lactic acid in the mash. I would take a sample after 5 min and add 1ml at a time. Switched to acid malt and havent looked back. Still put lactic acid in my sparge water.

 

[thehopbandit]

That looks high to me. I used to use lactic acid in the mash. I would take a sample after 5 min and add 1ml at a time. Switched to acid malt and havent looked back. Still put lactic acid in my sparge water.

Thanks for the reply. But, essentially, one would just add the lactic without worrying about other additions?

The mash water is around 10.6 gallons at 1.25 qts/lb, which may explain the somewhat high amount.

 

[IslandLizard]

It looks high to me too, with an alkalinity of only 23.

I'd use Brunwater's spreadsheet and see what that comes up with, I have no experience with EZ water or BF.

Are you on a BIAB system, sparging with only a small amount?

If you have a pH meter you can always do a test mash with 1/2 a pound of your grist mix, and the calculated acid addition. Dilute your acid, otherwise the addition may be too small to measure. Take a pH reading at 15-20 minutes (chill the sample to room temps), and another one at 40'. Then make adjustments for your main batch, or do another test mash. Add you test mashes to the main batch at the end, nothing's lost.

 

[IslandLizard]

Just thought of something, are you using 88% Lactic acid in your calculator? Not 10% Phosphoric or some other low dilution?

 

[dyqik]

Beersmith's mash pH tool is way off for me, compared to Bru'n'water and Brewer's Friend. It's also not clear to me how you tell Beersmith how much water is in your mash - adding water as an ingredient in multiple doses does some very weird things, AFAICT, and you can't add your strike and sparge water separately.

Both of the last two give results within 0.04 when I measure with my pH meter. This is with an alkalinity around 88 ppm. The general advice is to _not_ chase mash pH during the mash (too many other things are changing with time), but to predict, measure, and use that information for the next brew.

 

[thehopbandit]

I'd use Brunwater's spreadsheet and see what that comes up with, I have no experience with EZ water or BF.

I gave Bru'n Water a try, but had a couple issues. The grain bill input only lets you enter "base malt", but not a specific malt. Since there is a difference with the buffering of, say, 2-row versus Pilsner, I need to make sure it's using Pilsner stats.

Are you on a BIAB system, sparging with only a small amount?

No BIAB, just a regular batch sparge system. I am mashing at 1.25 qts/lb, which means for 34 lbs of malt, I'm mashing with 42.5 quarts of water.

I do have pH meter, so I will definitely spend some time testing this time around. My main concern was the process in which lactic is used.

Basically, assuming calculations are correct, all I would need to do would just be able to test and add to the mash water, stir, and retest, correct? I was just a little confused why I was seeing the RA drop to the -600's and if that was normal. I wasn't sure, if by adding just lactic, I'd be throwing off the other balances big time.

Just thought of something, are you using 88% Lactic acid in your calculator? Not 10% Phosphoric or some other low dilution?

I am using the 88% Lactic in Beer Smith. The calculator at the bottom of the "Mash" tab is calculating 18.1 ml of 88% lactic to bring the mash pH from 5.69 -> 5.3 for a 1.25 qts/lb mash (42.5 quarts of water).

Beersmith's mash pH tool is way off for me, compared to Bru'n'water and Brewer's Friend. It's also not clear to me how you tell Beersmith how much water is in your mash - adding water as an ingredient in multiple doses does some very weird things, AFAICT, and you can't add your strike and sparge water separately.

Both of the last two give results within 0.04 when I measure with my pH meter. This is with an alkalinity around 88 ppm. The general advice is to _not_ chase mash pH during the mash (too many other things are changing with time), but to predict, measure, and use that information for the next brew.

I tried Brewer's Friend's calculator too, and say the RA numbers shoot way down to -600's so I was confused by that. I normally have never worried about mash pH, but this is the first time I've seen it calculated that high, so I was a little worried and is why I wanted to look into adjusted the pH since it's going to be such a big beer.

UPDATE:
I tried running through Bru'n water again and entered all the stats. It looks like Bru'n water looks at lactic in terms of ml/gallon instead of a total amount. I tried different numbers and, assuming I entered things in correctly, it's looking like around .6 ml/gallon (6.4 ml total) of 88% lactic to bring the calculated pH from 5.62 (Bru'n Water) -> 5.3. This shoots the bicarbonate down to -111, so I'm still unclear what that means and if it's acceptable.

 

[Morrey]

FWIW, I use Bru'n Water for water chemistry management even though the malts are in general categories as you point out. I have spot checked with my ph meter behind the program many times only to find the program nailed the additions spot on.

For a 5.5G batch with 7.5G full vol strike water in a typical 1.050 beer with 11-12# grains, I use 3 mL lactic acid at 88%. Your proposed use seems high, but there are variables your source water and recipe will influence.

 

[thehopbandit]

FWIW, I use Bru'n Water for water chemistry management even though the malts are in general categories as you point out. I have spot checked with my ph meter behind the program many times only to find the program nailed the additions spot on.

For a 5.5G batch with 7.5G full vol strike water in a typical 1.050 beer with 11-12# grains, I use 3 mL lactic acid at 88%. Your proposed use seems high, but there are variables your source water and recipe will influence.

Thanks. I updated the post above with some info from Bru'n water. I gave it another try and it's calculating 5.62 expected mash pH. At ~10.6 of mash water, it's looking like it's calculating .6 ml/gallon (6.4 ml total) to bring the pH from 5.62 -> 5.3. I'm not sure why the massive difference from BeerSmith's calculation? Bru'n water does show the bicarbonate shoot down to -111 post lactic addition, so I'm still a little unclear if that's good or bad.

 

[Morrey]

Thanks. I updated the post above with some info from Bru'n water. I gave it another try and it's calculating 5.62 expected mash pH. At ~10.6 of mash water, it's looking like it's calculating .6 ml/gallon (6.4 ml total) to bring the pH from 5.62 -> 5.3. I'm not sure why the massive difference from BeerSmith's calculation? Bru'n water does show the bicarbonate shoot down to -111 post lactic addition, so I'm still a little unclear if that's good or bad.

I use BS for recipe building and it is a darn good program for that use. I have used BS for water management and can't get my ph meter to jive with mash ph it predicts. Not trying to sell you on anything other than experiences I have encountered, Brun'N Water hits the nail on the head for my purposes. I have learned to trust it completely.

 

[dyqik]

Thanks. I updated the post above with some info from Bru'n water. I gave it another try and it's calculating 5.62 expected mash pH. At ~10.6 of mash water, it's looking like it's calculating .6 ml/gallon (6.4 ml total) to bring the pH from 5.62 -> 5.3. I'm not sure why the massive difference from BeerSmith's calculation? Bru'n water does show the bicarbonate shoot down to -111 post lactic addition, so I'm still a little unclear if that's good or bad.

Bru'n'water uses negative/positive bicarbonate as a proxy for acidity/alkalinity (I forget the correct terms, see AJ's posts in the Brew Science sub-forum for accuracy). A pale grist needs acidity to bring the mash pH down, and what Bru'n'water is telling you there is that there is acidity present, which is what you want.

 

[Hwk-I-St8]

FWIW, I use Bru'n Water for water chemistry management even though the malts are in general categories as you point out. I have spot checked with my ph meter behind the program many times only to find the program nailed the additions spot on.

For a 5.5G batch with 7.5G full vol strike water in a typical 1.050 beer with 11-12# grains, I use 3 mL lactic acid at 88%. Your proposed use seems high, but there are variables your source water and recipe will influence.

I have similar results with Bru'n Water. I started out spot checking, but it was pretty much right on so I don't even double check anymore. Also, I just use acidulated malt. Add to the grain bill to get the pH I want after I've built up the RO water with the minerals I want.

In general, I don't think you want to "chase" the pH at mash time. Use a good tool to predict based on the recipe, check it 10 mins into the mash with the idea of adjusting the next time if needed.

 

[triethylborane]

I have similar results with Bru'n Water. I started out spot checking, but it was pretty much right on so I don't even double check anymore. Also, I just use acidulated malt. Add to the grain bill to get the pH I want after I've built up the RO water with the minerals I want.

In general, I don't think you want to "chase" the pH at mash time. Use a good tool to predict based on the recipe, check it 10 mins into the mash with the idea of adjusting the next time if needed.

+1 on the acidulated malt. A great way to hit a mash pH target.

 

[IslandLizard]

Looks like you got it under control.

Although you can take a pH reading during the actual mash, it's more for verification, peace of mind, but too late to change much or anything significant. Mash conversion proceeds quickly, chances are 40-50% is done after 15-20 minutes, especially with a finer milled grist. Stirring in an acid addition at that point trying to get it equally dispersed is another hurdle, while you're losing heat by the minute. Hence the test mash.

@dyqik is right, negative alkalinity is the acidity charge, and just there for reference, nothing you want to try to balance.

Martin or AJ may be able to give you more details in the Brew Science forum, and answer questions you may have regarding Bru'nwater, or water in general. It won't hurt to read some of the threads there, dealing with similar questions and issues that may have been addressed before. It's a very informative forum.

I only use BS for recipe formulation, ingredient substitutions, some conversions and tweaks, some tools. I don't use most of the other features, probably because I never learned to use them properly. Inventory is kept in Excel.

 

[thehopbandit]

Looks like you got it under control.

Although you can take a pH reading during the actual mash, it's more for verification, peace of mind, but too late to change much or anything significant. Mash conversion proceeds quickly, chances are 40-50% is done after 15-20 minutes, especially with a finer milled grist. Stirring in an acid addition at that point trying to get it equally dispersed is another hurdle, while you're losing heat by the minute. Hence the test mash.

Cool, thanks! Given that you said it doesn't make a whole lot of sense to do pH adjustments during the mash, do you think I should go ahead and add lactic according to Bru'n water pre-mash and hope it's within range, or just not make any adjustments and only measure for reference?

Since this is such a big, expensive beer, my only fear is that by not making any pH adjustments the mash will be hindered in some way given that the calculated pH is up between 6.62-6.69.

 

[dyqik]

Cool, thanks! Given that you said it doesn't make a whole lot of sense to do pH adjustments during the mash, do you think I should go ahead and add lactic according to Bru'n water pre-mash and hope it's within range, or just not make any adjustments and only measure for reference?

Since this is such a big, expensive beer, my only fear is that by not making any pH adjustments the mash will be hindered in some way given that the calculated pH is up between 6.62-6.69.

Yes, add lactic acid to Bru'n'water's recommendation. The window for pH is fairly wide, particularly if you hit your temperatures, so you only need to be somewhat close. Anywhere between about 5.2 and 5.5 will be OK, with good conversion efficiency.

The other thing you can do to insure yourself is to measure conversion, and only mash out/sparge once conversion is done. That's a matter of taking samples from a well mixed mash (easy if you recirculate), and measuring gravity with a refractometer. Compare to the values on Braukaiser's efficiency page for what you should get for your grain/water ratio.

 

[IslandLizard]

Cool, thanks! Given that you said it doesn't make a whole lot of sense to do pH adjustments during the mash, do you think I should go ahead and add lactic according to Bru'n water pre-mash and hope it's within range, or just not make any adjustments and only measure for reference?

Since this is such a big, expensive beer, my only fear is that by not making any pH adjustments the mash will be hindered in some way given that the calculated pH is up between 6.62-6.69.

What @dyqik says. ^

You definitely should make that adjustment before brewing.

If you're in doubt and want to verify correctness for a large/important batch:

• Add the minerals and acid to your volume of strike water (mix well)
• Use 1/2 or 1 pound of your well mixed grist, making sure you get a representative sample
• Use that strike water at the same water/grist ratio you intend to use later (that's important)
• Mash, and measure the pH of a (cooled) wort sample taken at 15-20 minutes. A thick glass from the freezer cools that ounce or so down fast.
• Take another one at 40' if you want the data of progression
• Make adjustments to the strike water if needed (hopefully none) and go ahead with the main batch. I would ignore a pH difference of 0.05 or smaller due to sample variation.

You only stand to "lose" 20-30' of your day with that test mash, but it could save the day in case a sizeable error was made.

Bru'nwater has never steered me wrong, mash pH being close (within 0.05 at the most) from expected. I usually aim for 5.35.

 

[thehopbandit]

You only stand to "lose" 20-30' of your day with that test mash, but it could save the day in case a sizeable error was made.

Awesome, thanks for the help. I think I'll give this a go.

 

[Morrey]

Although you can take a pH reading during the actual mash, it's more for verification, peace of mind, but too late to change much or anything significant. Mash conversion proceeds quickly, chances are 40-50% is done after 15-20 minutes, especially with a finer milled grist.

As IslandLizard points out, the impact of properly adjusted strike water is quite important. Some folks "chase" the mash ph as you saw a good point made, but conversion goes quite quickly in some cases.

Another HBT member (RM-NM) went to great lengths to test conversion speed and found it is extremely fast with fine grind like BIAB.

A quote from a previous thread:

Finally, you're not the first to report this "problem" @RM-NM is also a very fine grind BIAB'er who has seen similar effects. I think he does mostly 20 - 30 min mashes. He doesn't like to go shorter as he finds that beers with 10 - 15 min mashes lack flavor.


He found that 10 minutes into the mash, conversion was pretty well done with. YMMV of course depending on factors including grind.

 

[mabrungard]

Be careful! While it is true that our mashes convert their starch to sugars in just a few minutes, the fact is that those sugars are largely long-chain polysaccharides. It is therefore important that a mash continue for substantially longer to allow those time-dependent enzymatic reactions to chop the polysaccharides into more desirable di- and mono-saccharides that actually provide beer with more flavor. Dextrin-rich wort is not very tasty.

This starch conversion anachronism is another reason why the iodine test is essentially worthless. If you still have starch in your wort after 15 minutes of mashing, you have other problems.

Extending your mashing duration to at least a half hour (I mash at least an hour), is beneficial to beer flavor and fermentability. Big, chewy dextrinous beers are not very pleasant to drink.

 

[65C]

I have a Ph >7 (don't know exactly as my strips don't go high enough)

adding 5ml of lactic to 12L brings me down to 5.2