What's the most baking soda you ever added to a dark beer recipes mash?

[ajdelange]

Zero. The darkest beer I've brewed was a porter with 90% 2-row, 6% black patent malt, and 4% crystal 20. It still needed a considerable amount of lactic acid. That beer was really good. I will brew it again, but tweak it slightly (90% pale ale malt, 5% black patent, 5% C20) And it will again need about 5 ml of lactic acid for a 4 gallon mash.

Now that makes sense. Here's the snapshot for those conditions (90/5/5) and a target of pH 5.4 (the same as for cire's in No. 115).

I used the same water properties as cire and the same mash thickness. Without any acid you would probably land around 5.60 and have a deficit of 10.44 mEq/kg malt compared to his 11.06 thus he is going to need a bit more acid than you to hit pH 5.4 I calculate almost exactly 6.2 mL 88% lactic acid (11.44 mEq/ml) to cover those 71.2 mEq deficit. For pH 5.4 you'd need 3.0 whereas he would need 10.8 and 6.8 at those two pH's respectively.

Also, when I've brewed beers like these I get pH's of 5.5 - 5.6 without acid addition with similar water so we have a big disconnect here somewhere.

I don't think the malt color makes *that* much difference. It does make some difference,

Yes, DI pH, the major determinant of malt acidity is quite highly correlated with malt color except with the black malts. What people don't understand is that even though the correlation is tight color is not a good (or let's say not a terribly good) predictor of malt acidity characteristics.

and maybe some of y'all are brewing with distilled or deionized water. I'm using dechlorinated tap water that comes from deep limestone wells.

As you can see from the snapshot the water only accounts for 9 of the total estimated 71 mEq deficit of your mash re pH 5.4. Were we to remove the 80 ppm alkalinity from the water in your case the pH prediction would drop to 5.54 (from 5.60) aand the acid requirement for 5.40 would drop to 4.3 mL.

 

[ajdelange]

Even though metric isn't my first language I setup my software with the recipe @ciro posted to compare my results using Gen1 calculations.

You are also getting what ostensibly seems to be a very low pH estimate which means you have found the missing acidity. Where did you find it? Or rather perhaps, how do you estimate mash pH? I know you have posted that before but I'll never be able to find it. Can you point me to that post perhaps?

 

[cire]

Firstly AJ, may I commend and thank you for the detailed explanation of the theory and priciples involved. I was able to follow and understand all you wrote, but feel it may work better when brewing pale beers with low mineral levels such as Pilsner.

.......................To fix things with the water would mean getting 11 mEq/kg from calcium which, as it takes 7 mEq to get 1 mEq surfeit would mean adding 77 mEq or 38.5 mmol of a calcium salt per kg of malt. At the 2.25 L/kg thickness that would be 38.5/2.25 = 17.1 mmol/L and result in increasing the calcium ion over what is already in the water by 40 times that or 684 mg/L. That's a lot of calcium!

I expected the predicted calcium level to be significant, but not of such magnitude and perhaps makes this the crux of the matter. It was possible that I gave mineral levels that were marginally inaccurate, but it would be impossible for all or any to have this order of error. If 40 times more calcium be needed to correct the difference between my findings and the calculated pH, then wouldn't reducing alkalinity in accord to Kolbach's findings to something like 8 ppm similarly account for the discrepancy? This would be equally ridiculous to me as I regularly mash all pale malt grists in liquor with catons of similar amounts as the stout brew and alkalinity around 20 ppm to achieve pH 5.2 to 5.3. Were alkalinity to be that order for the stout, mash pH would almost certainly be less than 5.

A more practical approach would be to add lactic acid or Sauemalz. The rule of thumb for Sauermalz is 1% of the grist for each 0.1 pH reduction. Thus you'd need 2.1%. Using Sauermalz in the calculator says 3% would be needed. With lactic acid the calculator says 0.97 mL/kg for this mash. That works out to 2.25*0.97 = 2.18 mL/L mash water. That's not too much nor is 3% Sauermalz. That is probably the approach I would take but I would most certainly do a test mash!

When home brewing started in UK fifty five years ago, the expertise was with commercial brewers. Wine making at home was legal and that community supplied the enquiring homebrewers with advice that produced a great many dreadful beers. In his 1974 book, Dave Line advised how to brew an all grain version of Guinness made using 70% pale, 20% flaked barley and 10% roast barley, not magnitudes away from the brew under discussion. That recipe is still popular in UK to this day. I'd struggled with water to that time, but brewed 5 (imperial) gallons as specified with a teaspoon of calcium salts to both the mash and kettle. My water at that time had roughly 100ppm calcium and 250 ppm alkalinity as CaCO3, but the resulting beer was revelationary for me, that water could make a reasonably good stout.

I have never resorted to using lactic acid or sauermalz in a stout or porter. For such beers my supply water treated with mineral acid to reduce alkalinity to between 70 and 100 ppm as CaCO3 with various amounts of additional calcium salts can achieve any and every acceptable mash pH.

Finally I'll mention that when I make stouts with similar low percentages of black grains and water of about the same alkalinity and hardness as yours I get pH's of 5.5 - 6. Thus I have confidence that the models in the picture represent the malts available to me over here. I'll also comment that all potential errors in the numbers in the picture would be attributable to errors in the malt models. None of the calculation approximations used by Gen I calculators are used here.

That's rather telling. Before I could accurately control alkalinity although able to measure pH, all pale malt beers could have a mash pH slightly over 6. However, I can't ever remember making Dave Lines Guinness with a mash pH that high, even with alkalinity in excess of 200 ppm as CaCO3.

I wonder, is your alkalinity achieved by adding sodium (bi)carbonate. If so, might it react differently than alkalinty formed from calcium and magnesium?

 

[ScrewyBrewer]

You are also getting what ostensibly seems to be a very low pH estimate which means you have found the missing acidity. Where did you find it? Or rather perhaps, how do you estimate mash pH? I know you have posted that before but I'll never be able to find it. Can you point me to that post perhaps?

@ajdelange on closer inspection I now see @ciro posted (see #102) his mash parameters differently than what I used. I will try this again using the parameters shown below from his post. The mash calculations used are my take on Gen1 grain color and some of Riffe's prediction formulas.

13.77 lbs = 6.25 kg = 6250g Bairds 1823 MO
2.3 lbs = 1.05 kg = 1050g Flaked Barley
0.77 lbs = 0.35 kg = 350g Flaked Oats
1.1 lbs = 0.5 kg = 500g Flaked Barley
0.44 lbs = 0.2 kg = 200g Chocolate Malt

....mashed in 19 litres/5 gallons of liquor with alkalinity of 80 mg/L as CaCO3 and Calcium 83 ppm, magnesium 35 ppm, sodium 29 ppm, sulfate 125 ppm, chloride 144 ppm.

The pH meter was calibrated before and checked afterward read 5.40.

 

[ScrewyBrewer]

This is as close as I can get in predicting the mash pH and brewing water used in @ciro's recipe.

 

[ajdelange]

Firstly AJ, may I commend and thank you for the detailed explanation of the theory and priciples involved.

You are certainly most welcome but I am as interested in resolving this discrepancy as you are. I'll also note that the new spreadsheet I have been putting together breaks the problem down in such a way that it furnishes exactly the sorts of information I have been posting and is thus perfect for this problem.

I was able to follow and understand all you wrote, but feel it may work better when brewing pale beers with low mineral levels such as Pilsner.

There is one aspect to this which may indeed make it work better for low mineral beers and that is the question of how many protons are released by a mEq of calcium. Kohlbach's well known finding is that 3.5 mEq of calcium have released 1 mEq of protons by the time knockout is reached and that magnesium releases half as many. But we aren't concerned about knockout here but at the beginning of the mash. Also Kolbach's result presumably applies to pre WWII German brewing practices and this may or may not be applicable to British brewing in 2018.

If you tell me you have calcium at 83 mg/L (4.15 mEq/L) how much H+ should I assign to that? Following Kolbach that would be 4.15/3.5 = 1.2 mEq/L. At 2.25 mash thickness that's 2.7 mEq/kg which is appreciable compared to the 9.69 mEq/kg deficit for the malt. But if we assume that only half of these protons are released in the mash tun (which is what I asssume) then the proton surfeit from calcium is 1.35 mEq/kg there. Still not unappreciable. With your mash buffering estimated at 0.021 pH/mEq•kg the pH shift caused by calcium would be around 0.03. That doesn't go very far towards explaining a discrepancy of 0.2 pH but it isn't something we can brush off either. With softer water there is less calcium and thus less potential error ascribable to mis-modeling of it.

The rest of the problem depends entirely on the modeling of the malt. The range of dI pH and buffering for the colored malts is much wider than for the pale malts so I guess we could accord them higher potential for error based on that. But the black malts are more tightly grouped than the base malts or the crystal/caramels so I don't really see much in this suggestion. But I do recognize that fed bad malt data this calculator, as will any other, will return bad predictions.

I expected the predicted calcium level to be significant, but not of such magnitude and perhaps makes this the crux of the matter. It was possible that I gave mineral levels that were marginally inaccurate, but it would be impossible for all or any to have this order of error. If 40 times more calcium be needed to correct the difference between my findings and the calculated pH, then wouldn't reducing alkalinity in accord to Kolbach's findings to something like 8 ppm similarly account for the discrepancy?

I only calculated the calcium correction to illustrate that blaming incorrect reporting of calcium as the source of the discrepancy would be absurd. Taking out the alkalinity altogether would only change the estimated mash pH from 5.64 to 5.58.

This would be equally ridiculous to me as I regularly mash all pale malt grists in liquor with catons of similar amounts as the stout brew and alkalinity around 20 ppm to achieve pH 5.2 to 5.3.

This says that you are going to mix say 80% base malt with a DI pH of 5.6 or above with 20% of some crystal or caramel malt with a pH of around 5.1 - 5.4 (presumably it would be a reasonably light malt) and realize a pH of 5.2. That just doesn't make sense unless we ascribe a pH lowering effect to calcium that simply isn't realistic. One of the things I love about this new spread sheet it that it is easy to answer the question "How unrealistic?" The answer is that rather than the Kolbach factor being 7 (half in mash tun, half in kettle) it would have to be 0.64. That means that instead of requiring 7 mEq of calcium to produce a mEq of protons each mEq of Ca++ would produce 1.55 mEq of protons. Impossible.

(yes, Were alkalinity to be that order for the stout, mash pH would almost certainly be less than 5.

But calculation and my experience say that it will be around 5.5 - 6.0. That's what I get when I put the numbers in the calculator and that's what I measure when I make beers like this.

When home brewing started in UK fifty five years ago, the expertise was with commercial brewers. Wine making at home was legal and that community supplied the enquiring homebrewers with advice that produced a great many dreadful beers. In his 1974 book, Dave Line

His "The Big Book of Brewing" and Bravery's "Home Brewing Without Failures" are what got me started in this business.

....advised how to brew an all grain version of Guinness made using 70% pale, 20% flaked barley and 10% roast barley, not magnitudes away from the brew under discussion. That recipe is still popular in UK to this day.

When I make stout that's the recipe I use (though I think I got it from Michael Lewis's monograph rather than Dave Line. I've done it at least several times and I always get, with water of alkalinity of about 80 and hardness of about 110 (total) a mash pH of 5.5 - 5.6. Why are you getting 5.4? No answer proposed answer related to malt or minerals seems to adequately explain and that gain puts the limelight back on the pH measurements. But you assure us that you have properly calibrated the meter. Have you run a stability check on it?

Then I looked at the picture. The buffers! Your pH meter is only as accurate as the buffers you calibrate it with. I don't see any "NIST traceable" markings on those bottles. There have been reports on this forum by people who have bought buffers for pH meter calibration only to find that their actual pH's were quite a bit off from the package labeling. I am not suggesting that this is the case here but that it might be. Let's face it, I'm grasping at straws at this point. Bad buffers may be an unlikely explanation but at least it's one I can comprehend.

I'd struggled with water to that time, but brewed 5 (imperial) gallons as specified with a teaspoon of calcium salts to both the mash and kettle. My water at that time had roughly 100ppm calcium and 250 ppm alkalinity as CaCO3, but the resulting beer was revelationary for me, that water could make a reasonably good stout.

I have never resorted to using lactic acid or sauermalz in a stout or porter. For such beers my supply water treated with mineral acid to...

. A proton is a proton. It doesn't matter whether they come from an organic or inorganic acid (as long as the weak nature of the organic acids is taken into consideration). I only used lactic because it it the first acid button on my spreadsheet. In terms of pH control you should be looking at the mEq only. But of course the anion involves can have a big influence on the way the beer tastes. For the record, I don't use acids in a stout. As long as pH < 5.6 I generally call that close enough and certainly the results have been good in terms of a tasty product at the 5.6 level.

reduce alkalinity to between 70 and 100 ppm as CaCO3 with various amounts of additional calcium salts can achieve any and every acceptable mash pH.

If you've got 1.4 - 2 mEq/L of alkalinity to dispose of then you'll need 7 times that much calcium per liter i.e. 9.8 - 15 mEq/L. That's assuming the half/half split between mash tun and kettle for the Kolbach reaction. If we assume it all takes place in the mashtun that means the requirement could be onl 4.9 mEq at the low end. As we really haven't a clue as to how it divvies itself up the possible range of calcium requirement for pH control would be 4.9 - 15 mEq/L or 186 - 300 mg/L calcium. To my way of thinking that's a lot of calcium! 245 - 750 ppm calcium hardness.

That's rather telling.

It would be were it true but there was a typo there. It should have read 5.5 -5.6.

Before I could accurately control alkalinity although able to measure pH, all pale malt beers could have a mash pH slightly over 6.

That would take a base malt with a pretty high DI pH and huge alkalinity. Muntons MO and 400 ppm as CaCO3 would do it.

However, I can't ever remember making Dave Lines Guinness with a mash pH that high, even with alkalinity in excess of 200 ppm as CaCO3.

No. Even 200 ppm alkalinityu should only get you to about 5.75.

I wonder, is your alkalinity achieved by adding sodium (bi)carbonate. If so, might it react differently than alkalinty formed from calcium and magnesium?

It's moot but I'll comment that bicarbonate is bicarbonate in terms of its alkalinity whether it is paired with sodium, calcium or magnesium. Same for carbonate (except for the solubility issue with calcium carbonate).

 

[cire]

AJ, we have many objectives in common, but today has not been a good one for reasons without connection to this forum or beer in general. Accordingly I've sank several pints for comfort of a beer amongst the best I make and am in no state to participate in a high level exchange. However, after a quick read of your recent posting, neither can I go to my bed without responding to a couple of aspects.

We've discussed this previously, but you and I have vastly divergent opinions of the influence of alkalinity in a mash and despite your graphs, I strongly feel yours does not apply to my brewing regime and the way I treat water. While my comments may not be thought to be banter, I have no wish to sour these exchanges, so should you at this point be livid, please allow time for me to sober and find the words and examples to substantiate my understanding.

You are correct that the buffers I use do not come with certification. But as I'm sure you will know that in today's world a signed piece of paper, while often of little merit with a price to cover the cost of lawyers to dispute any dispute, are frequently more expensive than the value of the component itself. So one buys something reputable and then compares the results with known values to validate their use. Simple titration of naturally alkaline water with a strong mineral acid will find one drop of acid that will shift pH from 4.6 to 4.3 to confirm the meter and buffer to not be very far wrong while if it happens near pH 5 or pH 4 they are wrong. Similarly one can dilute an alkali or mineral acid of certified assay with DI water and compare the meter's reading with the calculated value. Knowledge can be worth more that currency.

Only a very few beers that require alkalinity to be absent to achieve a suitable mash pH and I find it hard to think those might include any darker than 20 EBC.

 

[ajdelange]

AJ, we have many objectives in common, but today has not been a good one for reasons without connection to this forum or beer in general.

Hope the morrow goes better for you.

We've discussed this previously, but you and I have vastly divergent opinions of the influence of alkalinity in a mash and despite your graphs, I strongly feel yours does not apply to my brewing regime and the way I treat water.

You are certainly entitlled to your opinions and beliefs but we are both subject to the laws of physics and, AFAIK they are the same both sides of the Greenwich meridian.

While my comments may not be thought to be banter, I have no wish to sour these exchanges, so should you at this point be livid, please allow time for me to sober and find the words and examples to substantiate my understanding.

No, not at all. I'll be happy to continue the discussions.

You are correct that the buffers I use do not come with certification. But as I'm sure you will know that in today's world a signed piece of paper, while often of little merit with a price to cover the cost of lawyers to dispute any dispute, are frequently more expensive than the value of the component itself.

NIST traceable buffers are not expensive.

So one buys something reputable and then compares the results with known values to validate their use. Simple titration of naturally alkaline water with a strong mineral acid will find one drop of acid that will shift pH from 4.6 to 4.3 to confirm the meter and buffer to not be very far wrong while if it happens near pH 5 or pH 4 they are wrong.

I think perhaps your "medicine" may have caused you to bobble the numbers but the concept is spot on!. I remembered that when I moved into this house I had done a titration on the well. It was a bear finding the data but I did. The graph below shows the titration data and a fit of the bicarbonate + water curve to the data. The fit parameters were Ct, the total carbo, and pK1, the first pK of carbonic acid. The values for these which gave the best fit were Ct = 3.565 mmol/L and pK1 = 6.4028 ± 0.0241. The former tells me that the alkalinity here is 162.4 ppm and the later, with the fact that the curve based on the chemistry fits well oer the entire data range, that my pH calibration is pretty darn good as the first pK of carbonic acid is 6.38 at 20 °C. So while it is true that an incremental addition of acid will bring about roughly the same pH shift any where between pH 3.8 and 5.2 it is true that if you do titration in small enough pH steps around 6.38 that you can detect the inflection point (I can't eyeball it - you'll probably need software) and if that inflection point is close to 6.38 and if you can get a decent fit between 4 and 7 you will have verified your calibration. Rather than using your tap water for this you could also use a solution of baking soda in DI water. This reminds me that I recently proposed using baking soda as the 'fiducial malt' in Riffe's scheme for measuring malt parameters. Thus I'm on board with the idea of using baking soda to check on a meter's calibration but what do you do if pK1 comes out to be 6.5 and the bicarbonate/water curve doesn't fit your data? It seems to me much simpler to just get some buffers you have real confidence in. That's what you are paying for. Interstingly enough I believe it is the lawyers we have to thank for inexpensive pH meters and high accuracy buffers. It is all the stupid regulations that require pH measurements in so many industries that stimulated the manufacturers to produce these in quantities so great that economies of scale kicked in.

Similarly one can dilute an alkali or mineral acid of certified assay with DI water and compare the meter's reading with the calculated value. Knowledge can be worth more that currency.

Yes, one could take some sodium bicarbonate and mix it with a certain amount of certified hydrochloric acid and - hey wait a minute - that's a standard formulation for 7 buffer. Why not just pay Hach company to do that for you. Standardized acids are more expensive than bufferd.

Only a very few beers that require alkalinity to be absent to achieve a suitable mash pH and I find it
hard to think those might include any darker than 20 EBC.

Nearly every beer I brew (many of which are over 20 EBC) require acid. Lots of sauermalz and lactic acid are sold in the US and Europe and lots of AMS is sold in the UK. The well known German brewing scientist Kunze wrote in his book that most beers require acid in some form. That acid is required to neutralize the alkalinity of the brewing water and the alkalinity of the base malts. So this statement just isn't true. I suspect that you and I have different ideas as to what 'alkalinity' is. To test this hypothesis here's the definition:

The alkalinity of a substance is the quantity of protons which must be added to a unit amount of that substance to bring it to a specified pH. Agree?

 

[ajdelange]

The mash calculations used are my take on [I]Gen1[/I] grain color and some of Riffe's prediction formulas.

The pH meter was calibrated before and checked afterward read [B]5.40[/B].

What I was trying to ask is whether you can look into the internals of you spreadsheet and tell which malt or malts are pulling the pH down to 5.4. I assume that if you zeroed out the amounts of all the malts except the MO you wouldn't get a pH of 5.4. But when you add some other malt or malts in it falls to that level. If we can identify that malt or malts (and its doubtless one or both black ones) I could then ask you to pass just that malt to the algorithm with distilled water and the estimate under those conditions would tell me what the algorithm is inferring for the di mash pH for that malt. This I could then compare to the di mash pH for similar malts in my collection and perhaps resolve the discrepancy in this way.

 

[ScrewyBrewer]

Ok got it now. Here is each individual grain pH using RO water.

Pale 2 Row-UK (3) 5.66 pH
Flaked Barley (2) 5.73 pH
FlakedOats (1) 5.75 pH
Roasted Barley (300) 4.84 pH
Chocolate (600) 4.95 pH

 

[ajdelange]

Ok got it now. Here is each individual grain pH using RO water.

Pale 2 Row-UK (3) 5.66 pH
Flaked Barley (2) 5.73 pH
FlakedOats (1) 5.75 pH
Roasted Barley (300) 4.84 pH
Chocolate (600) 4.95 pH

Using those numbers I can get to pH 5.41 but look what I had to do to the buffering:

None of those buffering values seem reasonable to me. I also had to set the Kohlbach factor to 3.5 indicating 100% proton release in the mash tun (and, consequently, none in the kettle which doesn't seem realistic). As an additional sanity check I installed the Riffe equation in the spreadsheet. It's result is in the bottom row at Linear Est. Note that it is the same as the non linear estimate (Est. pH) as it should be given that all the malt models are linear and that the water's proton deficit is computed at a pH (the target pH) which is very close to the estimated pH.

So it seems you are using the Riffe equation and I am using the Riffe equation and we are getting rather different answers. And the questions thus become
1)What are you using for buffering values for each of these malts?
2)What are you using for water proton deficit?

One more question: Where did you get the data for flaked oats? You have a DI pH of 5.75 for that. I found data from Riffe's paper that lists 6.21. That;'s quite a difference.

 

[cire]

They say confession is good for the soul. I hope it is.

Sorry to all, but the information given for the mash liquor was not correct. I hope you've not been sent up the garden path and apologise for wasting time, but it reduces the discrepancy between software prediction and my findings and hopefully might improve our collective knowledge and understanding.

In preparing additional figures for this thread, which will now be necessarily delayed, the old papers used to rest upon transpired to be the actual brewday notes and in them saw an error made during their transcription to my log. The mash appeared stuck and in effort to free it 2 litres of liquor from the HLT were added, but my log reports only "mash after rest was thought stuck but was an air lock". However, the contemporary notes record has 6g of calcium chloride dihydrate added to those 2 litres of additional liquor. Thus the actual mash liquor was 21 litres, Calcium 161ppm, Magnesium 35, sodium 29, sulphate 125, chloride 281ppm and alkalinity unchanged at 80ppm as CaCO3.

I'm utterly sorry about this, but if a calculator, as suggested earlier if I understood correctly, that an increase of almost 40 fold was required to reduce pH by 0.2, then this case of almost doubling calcium content mightn't be significant as far as the calculator is concerned.

Just to repeat, sorry to all for this error.

 

[ScrewyBrewer]

Using those numbers I can get to pH 5.41 but look what I had to do to the buffering:

View attachment 584670
So it seems you are using the Riffe equation and I am using the Riffe equation and we are getting rather different answers. And the questions thus become
1)What are you using for buffering values for each of these malts?
2)What are you using for water proton deficit?

One more question: Where did you get the data for flaked oats? You have a DI pH of 5.75 for that. I found data from Riffe's paper that lists 6.21. That;'s quite a difference.

Unless I'm reading this wrong my predicted mash pH is 5.34 and your sheet is showing a predicted mash pH of 5.41. Correct? Or is your sheet not attempting to predict the mash pH using these grains.

I left the strike water volume set to 19L then entered the individual grain amounts. I doubt the values of my pH predictions under those circumstances. In fact I'm coming to the conclusion that @ciro's example recipe is not valid at all.

 

[ajdelange]

Just to repeat, sorry to all for this error.

No apology necessary. Trying to run all this down has given me the opportunity to shake out my new spreadsheet in many different ways. I've discovered errors, added new features etc. because of the stimulus from this thread. So I definitely feel I am benefiting.

 

[Silver_Is_Money]

Unless I'm reading this wrong my predicted mash pH is 5.34 and your sheet is showing a predicted mash pH of 5.41. Correct? Or is your sheet not attempting to predict the mash pH using these grains.

I left the strike water volume set to 19L then entered the individual grain amounts. I doubt the values of my pH predictions under those circumstances. In fact I'm coming to the conclusion that @ciro's example recipe is not valid at all.

My understanding of this has been that A.J. has had to go to unusual extremes (as in, highly unlikely to be real extremes) with his malt data in order to get his software to hit 5.4 pH for cire's mash (as this mash was understood pre the recent news update from cire), and with A.J.'s most reliable malt data he was coming in at about 5.56 to 5.6 pH. I even recall A.J. pointing to a need for 3.4% acid malt (by grist weight) in order to hit pH 5.4.

With MME 3.00 (and also 3.10) I came up with a similar 5.54 pH for the recipe alone, and I needed 1.9% acid malt to bring it to 5.4.

But with the new revelation from cire everything has changed.

 

[ScrewyBrewer]

But with the new revelation from cire everything has changed.

Sigh...

 

[ajdelange]

Unless I'm reading this wrong my predicted mash pH is 5.34 and your sheet is showing a predicted mash pH of 5.41. Correct? Or is your sheet not attempting to predict the mash pH using these grains.

Yes, definitely estimating pH both with the Riffe method which I understood you to be using and with the full up non linear method. The last pair of estimates was obtained by taking the DI pH values you gave for each of the malts and tweaking the buffering, Riffe's B, until I got estimated pH's of near 5.4. To get an estimate that low I had to set the buffering for all the malts with pHDI > 5.4 to -20 mEq/kg•pH. This makes them less alkaline than normal base malts which typically have buffering values of -40. I also had to make the acidic malts, those with pHDI < 5.4 more acid than normal. I set buffering to -100 mEq/kg•pH for those. As you estimate 5.34 for malts with those same pHDI's you must have even less alkaline base malts and even more acidic colored malts. I was wondering what values for a1 (Riffe's Bi) you used.

To summarize at this point cire has posted data on a particular mash and reported pH of near 5.4 for it. When I see this my reaction is "Whoa, cowboy. That doesn't look right!" So I run calculations with what I think are reasonable models for the malts he described and come up with predicted pH almost 0.2 above that. But at least 2 guys come back with "Looks about right to me!" and offer calculations to support that conclusion. If fact you estimate even lower than 5.4 using Riffe's equation and malts with pHDI's that would require what I consider unreasonably small in the case of base malts and large in the case of dark malts buffering capacities. I want to get to the bottom of this. This sort of discrepancy is not that uncommon with Gen I sheets. Maybe we can find what is causing this and get it fixed. Gen I authors and users would potentially benefit.

I'm looking at the effects of forced linearity right now. The error that causes can vary quite a bit depending on the nature of the malts. As I had predicted, and this is hardly a surprise, the error is largest where malts with pHDI far removed from mash pH and large non linearity (Saurmalz would be the poster child) are used and where the water pH gets 9ish. But sometime the error from lineaerizing the water cancels the error from linearizing the malt.

 

[cire]

No apology necessary. Trying to run all this down has given me the opportunity to shake out my new spreadsheet in many different ways. I've discovered errors, added new features etc. because of the stimulus from this thread. So I definitely feel I am benefiting.

That's kind and I must also mention the great efforts by others too.

The original question asked about adding baking soda which I don't need becase my water contains an excess of natural alkalinity which I reduce using a suitable mineral acid, but never totally eliminate for if I did mash pH would be too low.

ScrewyBrewer, firstly sorry. You created a similar profile using typical brewing salts, but had to use baking soda to provide an equivalent quantity of alkalinity and while it otherwise reproduced the major ions present, might it have a different effect in a mash and therefore a vastly different influence on mash pH.

The nearest I can get with some knowledge of local geology was as follows...
73.72 mg/l common salt, NaCl supplying 29mg/l Na and 45 mg/l Cl.
152 mg/l Epsom Salts, magnesium sulphate dihydrate, MgSO4.2H2O supplying 15 mg/l magnesium and 59 mg/l sulphate.
118 mg/l gypsum, calcium sulphate dihydrate, CaSO4.2H2O supplying 27 mg/l calcium and 66 mg/l sulphate.
The remander would be alkalinity from the action of acid rain on limestone CaCO3 and dolomite CaMg(CO3)2. The latter would supply 20 mg/l magnesium and 33 mg/l calcium while the former 23 mg/l and both in combination produced alkalinity of about 220 ppm as CaCO3.

That supplied liquor was treated with hydrochloric acid, reducing it to 80 ppm as CaCO3 while increasing chloride by about 100 mg/l. When I add acid to reduce natral alkalinity, the liquor's pH falls. Does it not rise when baking soda is added to produce the same level of alkalinity? Would that be important?

Silver Is Money, firstly thank you. You quoted A.J. pointing to a need for 3.4% acid malt (by grist weight) in order to hit pH 5.4. Would you expect an extra 80 ppm calcium might have an equivalent influence?

 

[cire]

Would anyone wish to examine what this would produce? Recipe, any you care to choose.

 

[Silver_Is_Money]

Silver Is Money, firstly thank you. You quoted A.J. pointing to a need for 3.4% acid malt (by grist weight) in order to hit pH 5.4. Would you expect an extra 80 ppm calcium might have an equivalent influence?

I made guesses as to the nominal EBC colors of your grist components, and I applied your recipe and revised water analyticals and quantity to MME 3.10 Metric, and I came up with 5.46 as the mash pH, as can be seen below. Would you be able to provide us with the actual EBC (or 'L', as I can convert to EBC) colors for your malts please? Darker (higher valued) EBC's would drive what is presently 5.46 downward to some degree, and lighter would move the mash pH higher to some degree. And it is my opinion that if you measured your pH earlier than 30 minutes into the mash, your reading would come in low, so that (if the case) puts 5.40 pH as you measured it within reason.

 

[ajdelange]

Would anyone wish to examine what this would produce? Recipe, any you care to choose.

The salient thing about this mineralization is that if you assume that all the calcium that's going to react with malt phosphate does so in the mash tun the calcium reaction will nearly completely neutralize the alkalinity. With respect to pH then the result will be essentially that of a distilled water mash. Thus if we use the 80/10/10 Dave Line recipe we would get an estimated mash pH of 5.55 with this water and 5.56 with distilled water.[/QUOTE]

 

[cire]

My thanks to both.

Grist:-
Bairds 1823 MO 6 EBC
Crisp Flaked Barley 3 EBC
Crisp Flaked Oats 2 EBC
Bairds Roasted Barley 1300 EBC
Bairds Chocolate Malt 950 EBC

However, according to the data on Bairds website Roast Barley can be as high as 1500 EBC and Chocolate Malt up to 1100 EBC.

There is no question of that pH measurement being taken earlier than 30 minutes into the mash. The start of mash is recorded after mashing in. Mash duration is only rarely less than 90 minutes with no hurry to take any reading, my main concern being a rising pH being too high towards the end of the sparge. Sparging usually takes 2 and a half hours, sometimes more.

I've downloaded MME V3.1.

 

[ScrewyBrewer]

Yes, definitely estimating pH both with the Riffe method which I understood you to be using and with the full up non linear method. The last pair of estimates was obtained by taking the DI pH values you gave for each of the malts and tweaking the buffering...

@ajdelange I use Gen 1 color based calculations that aren't dependant on DI pH values. But in parallel, I use Riffe's earlier spreadsheet version formulas to look at cations/anions imbalance, pH Slope, and RA.

Several years ago I decided to move to Gen 1 color based calculations and away from what we now call Gen 2 grain DI pH based calculations. At that time less was known or discussed about grain buffering than we know today. Riffe's calculations as good as they are predict mash pH values 0.10 higher on average than color based predictions. I'm not happy about it because I don't understand why that would be.

I hope to make time to dig into Riffe's and your latest work over the coming months. As you know first hand codng is a time sinkhole.

 

[Silver_Is_Money]

My thanks to both.

Grist:-
Bairds 1823 MO 6 EBC
Crisp Flaked Barley 3 EBC
Crisp Flaked Oats 2 EBC
Bairds Roasted Barley 1300 EBC
Bairds Chocolate Malt 950 EBC

However, according to the data on Bairds website Roast Barley can be as high as 1500 EBC and Chocolate Malt up to 1100 EBC.

There is no question of that pH measurement being taken earlier than 30 minutes into the mash. The start of mash is recorded after mashing in. Mash duration is only rarely less than 90 minutes with no hurry to take any reading, my main concern being a rising pH being too high towards the end of the sparge. Sparging usually takes 2 and a half hours, sometimes more.

I've downloaded MME V3.1.

cire, with the nominal EBC colors adjusted to match your colors as seen above I still get 5.46 as the mash pH, and with the roast malts set to their darkest color extremes I get 5.45. But lastly, when I manually override and thus apply your measured 4.35 DI_pH to the chocolate malt I get 5.42 as the mash pH. From there to your measured 5.40 pH is merely splitting hairs. A minor tweak of the DI_pH of the roast barley to 4.54 (from the default 4.61) and MME is at 5.40.

 

[ScrewyBrewer]

ScrewyBrewer, firstly sorry. You created a similar profile using typical brewing salts, but had to use baking soda to provide an equivalent quantity of alkalinity and while it otherwise reproduced the major ions present, might it have a different effect in a mash and therefore a vastly different influence on mash pH.

@cire no worries. My program targets brewers like myself who use reverse osmosis or distilled water as a source for their mash water. I tried to replicate your water profile the best I can by adding the common brewing minerals I use. Based on my own brewing experience ranging from Kolsch to Porters I am satisfied with my pH predictions. When the predictions are off they're not off by that much.

Brewing the same recipe a second or third time. And making adjustments based on actual mash pH values recorded from prior mashes help in making the actual and prediced pH values more closely align. Call it intuative brewing or a 'sneaker network' requiring manual intervention for lack of a better term but it does work.

 

[Silver_Is_Money]

Within reasonable bounds for typical water pH, alkalinity as derived from baking soda and the same ppm measure of alkalinity as derived from natural (earth) processes upon water should make no difference. Either way you have the exact same dissociated HCO3- ions present within the mash water.

 

[ScrewyBrewer]

cire, with the nominal EBC colors adjusted to match your colors as seen above I still get 5.46 as the mash pH, and with the roast malts set to their darkest color extremes I get 5.45. But lastly, when I manually override and thus apply your measured 4.35 DI_pH to the chocolate malt I get 5.42 as the mash pH. From there to your measured 5.40 pH is merely splitting hairs. A minor tweak of the DI_pH of the roast barley to 4.54 (from the default 4.61) and MME is at 5.40.

Just a thought. What about changing the malt's color? Example if a Pale Malt has an SRM of 2.0 wouldn't changing the malt's SRM color to 1.8 have the same effect as altering it's purported DIph value.

 

[ScrewyBrewer]

Within reasonable bounds for typical water pH, alkalinity as derived from baking soda and the same ppm measure of alkalinity as derived from natural (earth) processes upon water should make no difference. Either way you have the exact same dissociated HCO3- ions present within the mash water.

That's what I was hoping to hear thank you. A brewer not using RO water can replicate their tap water by entering common minerals based on their water report as I did with @cire's recipe. From there they can then make adjustments to match a particular water profile.

 

[Silver_Is_Money]

Just a thought. What about changing the malt's color? Example if a Pale Malt has an SRM of 2.0 wouldn't changing the malt's SRM color to 1.8 have the same effect as altering it's purported DIph value.

No, as in this case cire has actually measured measured his MO base malts DI_pH and got 5.73. Mash Made Easy defaults Maris Otter (at 2.8L or 6 EBC color) to 5.73 DI_pH by design. So to select a different DI_pH via manual override (with such being easy to do) would for this case be highly disingenuous.

But you are correct in that lowering base malt DI_pH is one way to lower the predicted overall mash pH. But it must meet with reality, and the measured reality here is 5.73 for the MO, and 4.35 for the chocolate. This leaves openings for all of the other grist components to have measured DI_pH's that differ to some degree from their software calculated defaults, but unless cire does test mashes for each component, one must guess as to the most likely candidate. And I guessed the roast barley.

 

[cire]

Many thanks again. As a non-believer I'm impressed that we have, after uncovering my error, got somewhere close to agreement. However, I'd love to know what should be done to MME to make it spit out what it thinks, especially as I have a fairly comprehensive log of many brews even if on occasion it contains incorrect transcriptions. This is as far as I have managed. As you might see I've chosen to use the upper value for EBC provided by Bairds. If you recall I found similar with their Brown Malt.

Please tell me what I am not doing or am doing wrongly.