Will ~4.3 grams of Pickling Lime neutralize 12 Oz. of a typical Acid Malt?

[Silver_Is_Money]

I'm planning to brew a Dry Irish Stout, and I'd like to substitute 12 Oz. of Acid Malt for 12 Oz. of the recipes base malt in order to induce some old fashioned Guinness like twang (lacking better terminology here). But I would also want to fully neutralize this 12 Oz. of Acid Malt via the use of Calcium Hydroxide (Pickling Lime). I've preliminary worked out that roughly 4.3 grams of pickling lime should be sufficient to neutralize 12 Oz. of a nominally average strength Acid Malt. Is ~4.3 g. of Ca(OH)2 the correct amount to add, or should I plan to add some other quantity of pickling lime?

 

[Big Monk]

I'm planning to brew a Dry Irish Stout, and I'd like to substitute 12 Oz. of Acid Malt for 12 Oz. of the recipes base malt in order to induce some old fashioned Guinness like twang (lacking better terminology here). But I would also want to fully neutralize this 12 Oz. of Acid Malt via the use of Calcium Hydroxide (Pickling Lime). I've preliminary worked out that roughly 4.3 grams of pickling lime should be sufficient to neutralize 12 Oz. of a nominally average strength Acid Malt. Is ~4.3 g. of Ca(OH)2 the correct amount to add, or should I plan to add some other quantity of pickling lime?

What is the total grain weight?

I’ve used up to 9% Sauermalz in beers where the main base malt had high DI pH and I never got any sourness/twang. You might be barking up the wrong tree.

 

[Silver_Is_Money]

The grist would be 13.05 lbs. in total.

10.75 lbs. of which would be base malt. Plus 0.65 lbs. each of Roast Barley and Black Barley. And lastly 1 lb. of Flaked Barley.

I was going to convert the 10.75 lbs. of base malt into 10 Lbs. base malt and 12 Oz. of Acid Malt.

 

[Big Monk]

The grist would be 13 lbs. in total.

10.7 lbs. of which would be base malt. Plus 0.65 lbs. each of Roast Barley and Black Barley. And lastly 1 lb. of Flaked Barley.

I was going to convert the 10.7 lbs. of base malt into 10 Lbs. base malt and 12 Oz. of Acid Malt.

That’s about 5 ish % Sauermalz. Can’t see getting any “twang” at all from the use of Sauermalz, especially at that percentage.

I guess the easiest thing to do would be to calculate the mEq of Sauermalz at that weight and then find the amount of mEq of Lime that would neutralize it.

I don’t have my stuff at hand at the moment or else I’d check it.

 

[Silver_Is_Money]

Lactic Acid = 90.08 MW, Valance = 1
Ca(OH)2 = 74.093 MW, Valance = 2

12 Oz. x 28.35 g/Oz. x 3.1% Lactic Acid = 10.546 g. Lactic Acid
10.546/90.08 = 0.11707

74.093/2 x 0.11707 = 4.34 grams

If Acid Malt has the acid equivalent of ~3.1% Lactic Acid by weight, then ~4.3 grams of Ca(OH)2 appears to be the correct answer.

But does Acid Malt have the acid equivalent of ~3.1% Lactic Acid by weight?

 

[ba-brewer]

cant help you on your math question, but some british yeasts can add a tartness to the beer. I see people commenting that S-04 can make a tart beers.

 

[Big Monk]

Lactic Acid = 90.08 MW, Valance = 1
Ca(OH)2 = 74.093 MW, Valance = 2

12 Oz. x 28.35 g/Oz. x 3.1% Lactic Acid = 10.546 g. Lactic Acid
10.546/90.08 = 0.11707

74.093/2 x 0.11707 = 4.34 grams

If Acid Malt has the acid equivalent of ~3.1% Lactic Acid by weight, then ~4.3 grams of Ca(OH)2 appears to be the correct answer.

But does Acid Malt have the acid equivalent of ~3.1% Lactic Acid by weight?

No. You can’t model Sauermalz as Lactic Acid because it’s malt and it’s Sauergut. Both of which can’t be modeled as equivalent amounts of Lactic acid.

 

[Silver_Is_Money]

But Kai Troester carried out specific acidity titrations for Acid Malt (Sauermalz), and he came up with rather close to 3% Lactic Acid equivalent on a weight for weight basis. I quote him and list the source:

Acidulated malt (Weyermann Sauermalz) was also included in the titration tests. One titration test determined a specific acidity of 315 mEq·kg-1 while another test determined 358 mEq·kg-1. This corresponds to a lactic acid content of 2.85 % and 3.22 % by weight and matches Weyermann's specification of ~ 3% (w/w)

http://braukaiser.com/documents/effect_of_water_and_grist_on_mash_pH.pdf

And in addition to the above I seem to recall a couple forum posts from A.J. on this topic in the past, wherein his titrations of several individual lots of Acid Malt are not all that far off from those of Kai Troester.

 

[FunkedOut]

Wouldn’t that twang you’re looking for be related to the sourness (low pH)?
If you raise the pH back up, wouldn’t that remove the twang?

I’m thinking this is what’s behind scotty’s first post in this thread.

 

[Silver_Is_Money]

Wouldn’t that twang you’re looking for be related to the sourness (low pH)?
If you raise the pH back up, wouldn’t that remove the twang?

I’m thinking this is what’s behind scotty’s first post in this thread.

When Kai Troester and a few of his friends performed their taste testing to determine the flavor threshold of lactic acid, he neutralized it to calcium lactate. And he did so with Pickling lime no less. I'm now seeing that it would take well more than 12 Oz. though. Many of Kai's 8 panelists could not detect lactic acid weighing in at 7.5% acid malt by grist weight, and some panelists had difficulty tasting it at up to 13% of grist weight. So my 5% by weight proposal isn't going to be detected. I'm now leaning to the use of S-O4 yeast, as suggested above by @ba-brewer. Either that, or I bump the neutralized Acidulated Malt (Sauermalz) up to 2 lbs. Or both.

Two questions still remain though:
1) Is the nominal acidity of Sauermalz equivalent to ~3% to 3.1% by weight lactic acid in a base malt. **
2) Is 4.3 grams the nominal amount of calcium hydroxide required to neutralize 12 Oz. of a nominal strength Acid Malt.

** Kai Troester presumed Acid Malt to be the equivalent of 3% by weight lactic acid in base malt for his testing, as stated in his article.

http://braukaiser.com/wiki/index.php?title=Lactate_Taste_Threshold_experiment

 

[Big Monk]

When Kai Troester and a few of his friends performed their taste testing to determine the flavor threshold of lactic acid, he neutralized it to calcium lactate. And he did so with Pickling lime no less. I'm now seeing that it would take well more than 12 Oz. though. Many of Kai's 8 panelists could not detect lactic acid weighing in at 7.5% acid malt by grist weight, and some panelists had difficulty tasting it at up to 13% of grist weight. So my 5% by weight proposal isn't going to be detected. I'm now leaning to the use of S-O4 yeast, as suggested above by @ba-brewer. Either that, or I bump the neutralized Acidulated Malt (Sauermalz) up to 2 lbs. Or both.

Two questions still remain though:
1) Is the nominal acidity of Sauermalz equivalent to ~3% to 3.1% by weight lactic acid in a base malt. **
2) Is 4.3 grams the nominal amount of calcium hydroxide required to neutralize 12 Oz. of a nominal strength Acid Malt.

** Kai Troester presumed Acid Malt to be the equivalent of 3% by weight lactic acid in base malt for his testing, as stated in his article.

http://braukaiser.com/wiki/index.php?title=Lactate_Taste_Threshold_experiment

My experience tells me that trying to do weight based Sauermalz calculations gets wonky.

Just calculate mEq of Sauermalz directly and then calculate the mEq value of pickling lime that will zero it:

Qmalt + QCa(OH)2 = 0

Even then though, I don’t think this is going to give you the desired effect.

 

[ajdelange]

Yes, 4.3 g Ca(OH)2 comes very close to neutralizing the acidity in 12 Oz of sauermalz at pH 5.4. But as has been pointed out if you neutralize the acid it won't give you the desired effect. As has also been suggested here the best way to get tart beer is probably to select a yeast strain that 1)takes it to a lower pH and 2)does that by producing acids whose tartness comes with anions with the desired flavors.

 

[ajdelange]

Two questions still remain though:
1) Is the nominal acidity of Sauermalz equivalent to ~3% to 3.1% by weight lactic acid in a base malt.

No. Not at all. The titration curve for a kg of sauermalz (in some reasonable volume of water) is not at all like the titration curve for 30 grams of lactic acid in that same volume.

2) Is 4.3 grams the nominal amount of calcium hydroxide required to neutralize 12 Oz. of a nominal strength Acid Malt.

Yes. Depends on the particular sauermalz and the pH, of course. Use the method in No. 11.

 

[Silver_Is_Money]

Was my chemical balance solution deriving 4.3 grams of Ca(OH)2 (as seen in post #5 above) merely a freak occurrence of random luck in its match to the correct answer?

 

[ajdelange]

Well not quite "freak, random luck". Kai understands the chemistry so when he says the acid equivalence is 3.5% he is talking about approximate acid equivalence in a narrow range of pH.

The "valence" of lactic acid isn't one nor is that of Ca(OH)2 equal to 2. Nor does 965 grams of malt onto which 35 grams of lactic acid has been sprayed behave like 35 grams of lactic acid. What you would have to do is plot out the titration curve of sauermalz and the titration curve of lactic acid and then scale the lactic acid curve to come as close as possible to the sauermalz curve over some range of interest (presumably the range of desired mash pH's). This is what Derek is talking about in No. 11. The curves below do this for 1 kg of Weyermann's sauermalz and 31.3 grams of lactic acid.

The fit was done over the region pH 4.6 to 6 and, as the graph shows, the match is perfect at about 5.45. In other words, 31.3 grams of lactic acid are equivalent in acidity to 1 kG of Wyermann's Sauermalz at pH 5.45. At any other pH this equivalent does not hold. Thus at pH 5.45 Wyermann's sauermalz has an effective lactic acid content of 3.13%.

 

[Big Monk]

Well not quite "freak, random luck". Kai understands the chemistry so when he says the acid equivalence is 3.5% he is talking about approximate acid equivalence in a narrow range of pH.

The "valence" of lactic acid isn't one nor is that of Ca(OH)2 equal to 2. Nor does 965 grams of malt onto which 35 grams of lactic acid has been sprayed behave like 35 grams of lactic acid. What you would have to do is plot out the titration curve of sauermalz and the titration curve of lactic acid and then scale the lactic acid curve to come as close as possible to the sauermalz curve over some range of interest (presumably the range of desired mash pH's). This is what Derek is talking about in No. 11. The curves below do this for 1 kg of Weyermann's sauermalz and 31.3 grams of lactic acid.

View attachment 610310


The fit was done over the region pH 4.6 to 6 and, as the graph shows, the match is perfect at about 5.45. In other words, 31.3 grams of lactic acid are equivalent in acidity to 1 kG of Wyermann's Sauermalz at pH 5.45. At any other pH this equivalent does not hold. Thus at pH 5.45 Wyermann's sauermalz has an effective lactic acid content of 3.13%.

This also explains why I was historically having to use what seems like weird Lactic Acid % in order to match what I was seeing in the brewery. The pH dependence.

 

[Silver_Is_Money]

So within a reasonable pH range I'm not far off in my (deeply Kai Troester inspired) thinking. Thanks A.J. And Derek!

 

[ajdelange]

No, your'e not (yes, you can use this approximation). But remember my quest is to get these approximations out of the calculation part of pH prediction, addition determination etc.

Something I forgot to mention in No.15: Note that the lactic acid curve is clearly leveling off at the higher pH's. The region where the curve is level represents the region at which the "valence" equals -1.

 

[Silver_Is_Money]

Can we definitively state from all of this that any/all brands of Acid Malt are not merely going to be found to be a base malt that has been sprayed with lactic acid? Or is this knowledge only affirmable for the specific case of Sauermalz (which is a brand name of acidulated malt to my knowledge)?

 

[Big Monk]

Can we definitively state from all of this that any/all brands of Acid Malt are not merely going to be found to be a base malt that has been sprayed with lactic acid? Or is this knowledge only affirmable for the specific case of Sauermalz (which is a brand name of acidulated malt to my knowledge)?

Sauermalz IS acid malt.

It’s typically going to be made by a European maltster and will be pils malt sprayed with Sauergut, not straight Lactic Acid.

 

[ajdelange]

Not sure it is Pils malt - looks a little dark for that. Also it can be made by wetting normal malt and innoculating it with L delbruekii. This is kind of a fun little project for the home brewer.

 

[Big Monk]

Not sure it is Pils malt - looks a little dark for that. Also it can be made by wetting normal malt and innoculating it with L delbruekii. This is kind of a fun little project for the home brewer.

It’s °L value is usually in the low 2s so I just always assume it was Pils malt that darkened a touch when the Sauergut was added.

 

[z-bob]

Not sure it is Pils malt - looks a little dark for that. Also it can be made by wetting normal malt and innoculating it with L delbruekii. This is kind of a fun little project for the home brewer.

That does sound like a fun project, but normal malt is already loaded with L delbruekii, or at least some kind of L. I'm brewing with Sauergut today (first time to use it!) that I started a couple of weeks ago using a handful of malt for the inoculant.

 

[ajdelange]

For your home experiment you don't have to inoculate as it is already there. Were you to do this on a commercial scale you might want to inoculate using a strain you like or to be sure of a quick kickoff. When German and Czech brewers started using sauermalz, doubtless invented by accident, they didn't innoculate.

 

[mabrungard]

I would be VERY surprised with a maltster inoculates their malt to create acid malt. As already pointed out, grain is teeming with acid forming bacteria and all it takes is a minor modification of malting procedure to get it to go 'sour'. Anyone who has left there spent malt in a moist pile will know this is true. A little time in a thick pile will invite the anaerobic condition that acid-producers desire, is all that is needed.

 

[ajdelange]

Well we all learn something every day.

 

[Big Monk]

I would be VERY surprised with a maltster inoculates their malt to create acid malt. As already pointed out, grain is teeming with acid forming bacteria and all it takes is a minor modification of malting procedure to get it to go 'sour'. Anyone who has left there spent malt in a moist pile will know this is true. A little time in a thick pile will invite the anaerobic condition that acid-producers desire, is all that is needed.

That all seems a bit uncontrolled to me. The standard production method, as I have always understood it, is to steep or spray Sauergut on the malt then dry it.

The following is from Kunze v.5.0:

Someone like Weyermann, who has a pilot brewery on premises, would find it easy to just take their normal pils malt, treat it with Sauergut (which we know they have in abundance because they sell it: https://www.weyermann.de/arg/gelbe_seiten_arg.asp?go=sg&umenue=yes&idmenue=712&sprache=18), and then dry it.

I have always thought, and it would seem to make a lot of sense, that the maltster would have more control by treating the malt with a known strength of Sauergut. Since the culture is active only up to certain temps, I would think the drying involves heat to kill of any residual lacto, thus stabilizing the acid percentage for that specific batch.

I could be way off here but that is how I have always understood it.