Help needed with the water chemistry

[cire]

So clearly your Brown malt is lots more acidic than OP's. What's its DI mash pH?

Not previously measured. Might have time to test it tomorrow.
I confess to expecting a higher pH than was measured, although I've never brewed with such a high proportion of brown malt.

 

[ajdelange]

I've been staring at the data. Eighteen grams of this malt neutralized the alkalinity of 31 grams of MO and of almost 2 mEq/L alkalinity to pH 5.1. Clearly its pHDI must be well less than 5.1 for this to happen but how much lower? It's a pretty simple matter to compute the protons required to get 31 grams of MO to 5.1, to get 150 mL of water with alkalinity 1.96 mEq/L to 5.1, and to compute the Kolbach H+ contribution from the 5 mEq/L calcium. Doing that we find a deficit of, intertingly enough, almost exactly 1 mEq. The protons delivered by the 18 grams Brown Malt depend both on the malt's DI pH and its buffering (a). The curve below shows combinations over a reasonable range of a.

The usual range for a is 20 < a < 60 implying a DI pH of < 4.2 for this malt which is really low for a 65 °L malt so I am really interested to see where this malt measures. Of course it is possible that the buffering is unusually high relative to crystal/caramel malts of similar color and perhaps that is a characteristic of Brown Malts. Thus I am really hopeful that one or the other of you will take a second pH measurement with some bicarbonate added to give us data on a.

 

[Silver_Is_Money]

As I stated earlier, the lowest DI_mash pH recorded by Biess for any deep roasted malt was 4.24 (in the data they released to me). This particular malts Lovibond color was 630, which goes well beyond 65L. Briess tested a single lot of crystal malt of around 170 Lovibond at a DI_mash pH of 4.20, with this being the absolutely lowest DI_mash pH they recorded for any individual malt (in data provided to me). But even darker crystal malts that they tested (as dark as 220L) did not get as low as this single outlier at 4.20 pH, and the lowest among the other extremely dark crystal malts (which as crystal malts are are listed separate in the data from their caramel malts, and I suspect may have been from competators) came in at about 4.30 pH.

If DI_mash pH can not be respectably correlated to malt acidity, then I wonder why all of the various maltsters spend so much time in their respective labs testing for their malts DI_mash pH values.

 

[cire]

So clearly your Brown malt is lots more acidic than OP's. What's its DI mash pH?

DI mash pH 4.52 after 20 minutes.

 

[Silver_Is_Money]

DI mash pH 4.52 after 20 minutes.

Seems completely believable. Thanks much for doing this test!!! Indeed your Brown malt is somewhat more acidic than that of the OP.

But it still seems as if your Maris Otter and Brown malt test mash in 98 ppm alkalinity water with the addition of Ca++ at 100 ppm should have come in at closer to a mash pH of 5.35 than your actual test result of 5.1. Are you highly confident that your 31g MO and 18g Brown test mash was carried out in strike water with 98 ppm alkalinity and 100 ppm of Ca++ ions? And was your amount of strike water for this test an exact scaled ratio match for the recipe given to us by the OP? And lastly, did you measure the pH at mash temperature, or at room temperature? 5.35 pH measured at room temperature would be very close to 5.1 pH if measured at mash temperature.

 

[cire]

Seems completely believable. Thanks much for doing this test!!! Indeed your Brown malt is somewhat more acidic than that of the OP.

But it still seems as if your Maris Otter and Brown malt test mash in 98 ppm alkalinity water with the addition of Ca++ at 100 ppm should have come in at closer to a mash pH of 5.35 than your actual test result of 5.1. Are you highly confident that your 31g MO and 18g Brown test mash was carried out in strike water with 98 ppm alkalinity and 100 ppm of Ca++ ions? And was your amount of strike water for this test an exact scaled ratio match for the recipe given to us by the OP? And lastly, did you measure the pH at mash temperature, or at room temperature? 5.35 pH measured at room temperature would be very close to 5.1 pH if measured at mash temperature.

You should not expect my figures to be as accurate as would be obtained in a laboratory, nor are they checked by a second individual until others like yourself examine them. Accordingly my findings are given in good faith, from measurements obtained using uncertified equipment believed to be sufficiently accurate for the purpose in mind on a kitchen bench.

pH measurements were made after the sample was chilled to 25C with a calibrated meter of which I have no reason to doubt its findings. Should you care to double check, the grains and liquor used in my test mash I think to be within 2% of the ratios in the OP's mash recipe. A fact not reported was the quantiy of magnesium present.

When reading the first posting I was as surprised as everyone by the calculated pH. I don't use pH calculators, it being quite easy to do a test mash while setting up to brew, and so it was for this thread as it lengthened. I thought that pH 5.4 would be a very likely outcome with that grist and liquor ratio with more calcium as was the OP's intention, so I treated some of my own tap water, reducing alkalinity to what I'm confident was close to 98 mg/l as CaCO3 and increased the calcium from 9 to 100 mg/l and a proportional increase in magnesium to 44 mg/l as that was more simple with my water. I was again surprised to measure pH 5.10.

I can't recall brewing with less than 70% base malt and in this case that is less than 65%. When brewing dark beers with 70% base malt I extend the mash to 2 hours and do wonder what part the enzymes play that calculations might not incorporate or recognise.

The brown malt in DI was done in similar way. Liquor in a 20 oz glass warmed in microwave while domestic oven raised and set to 65C. When glass and liquor contents were 73C the grain was mashed in and stirred, temperature measured and contents placed in the oven. A probe in the oven recorded temperature of air near sample when the oven could be manually operated to compensate any temperature drop. Not perfect, but practical.

In the case of test mash for brewing 1 or 2 percent of each item of the grist is added to the same proportion of additional mash salts and liquor, the grains and salts first placed into a plastic food box and shook until homogenously mixed. Any necessary adjustment will be to the alkalinity by a measured amount of acid or more alkaline, untreated, water.

 

[Silver_Is_Money]

I applied your Brown malt DI-mash pH result of 4.51 onto the OP's recipe while using his provided water analysis figures and his 3.75 gallons of strike water, and then I took two snapshots of 'Mash Made Easy', one without any additional added calcium, and one with calcium chloride added to achieve an overall 100 ppm Ca++. The former mashed at 5.40 pH per MME, and the later mashed at 5.23 pH per MME. The two snapshots are attached.

 

[cire]

Sorry, I'm not sure how I might be expected to respond.

So if 40 ppm magnesium was added to the liquor, it might then suggest a mash pH of ~ 5.2.
As a non-believer, I'm not surprised by a discrepancy of 0.1 pH by such calculations. Further, as a brewer, 0.1 deviation from target of mash pH wouldn't phase me either, although if found at the stage of the test mash some adjustment may be thought necessary. There are many aspects of brewing where differences can have vastly more significant consequences than small variations in mash pH.

 

[ajdelange]

DI mash pH 4.52 after 20 minutes.

Thanks for taking the time. This says the buffering is 90 or more. I have measured as high as 90 (on a Briess 80L caramel) but have only seen over that with sauermalz (as have others that I am aware of). So I'd be really interested in what the buffering is for this malt if you would be inclined to take another measurement (or 2). Given that it appears that the buffering must be nearly 100 mEq/kg•pH we'd need to absorb 10 mEq/kg to get the pH to rise by about 0.1 so that if you mashed 100 g (to get the required bicarb up to where you can measure it) you would need to add about 1 mEq's worth of absorber. This would be 84 mg of NaHCO3 (as it absorbs almost 1 mEq/mmol at pH 5.6).

 

[ajdelange]

Seems completely believable. Thanks much for doing this test!!! Indeed your Brown malt is somewhat more acidic than that of the OP.

But it still seems as if your Maris Otter and Brown malt test mash in 98 ppm alkalinity water with the addition of Ca++ at 100 ppm should have come in at closer to a mash pH of 5.35 than your actual test result of 5.1.

That is true if the buffering is only what one would expect it to be (45) but if it is higher than this (90 - 100 and, as noted in #49 I have measured as high as 90) then the answer he got is perfectly reasonable. That's why I am so interested in the buffering. Is the difference between Brown Malt and Caramel/Crystal malts of similar color that the former has higher buffering? I'd think that would be a valuable thing to know.

 

[ajdelange]

I applied your Brown malt DI-mash pH result of 4.51 onto the OP's recipe while using his provided water analysis figures and his 3.75 gallons of strike water, and then I took two snapshots of 'Mash Made Easy', one without any additional added calcium, and one with calcium chloride added to achieve an overall 100 ppm Ca++. The former mashed at 5.40 pH per MME, and the later mashed at 5.23 pH per MME.

OK but what did you use for the buffering?

 

[Silver_Is_Money]

Sorry, I'm not sure how I might be expected to respond.

So if 40 ppm magnesium was added to the liquor, it might then suggest a mash pH of ~ 5.2.
As a non-believer, I'm not surprised by a discrepancy of 0.1 pH by such calculations. Further, as a brewer, 0.1 deviation from target of mash pH wouldn't phase me either, although if found at the stage of the test mash some adjustment may be thought necessary. There are many aspects of brewing where differences can have vastly more significant consequences than small variations in mash pH.

Your response was perfect, as the key to getting a best case match between us is for both of us to be comparing as precisely possible apples to apples, and not apples to oranges. I've therefore added sufficient Epsom Salt to bring 40 ppm of Mg++ ions into the strike water, while maintaining your 4.51 DI-pH for the Brown malt, and now with MME the recipe mashes at a pH of 5.14, which is getting right close to your test mash pH of 5.10. See below:

 

[Silver_Is_Money]

OK but what did you use for the buffering?

I'm not at all confident that I've got the entire buffering thing fully down pat within the inner workings of MME. Rather in all honesty I would say that for the current edition of MME I do not at all have it right. But since you have been guiding and educating us as to the importance of the inherent variability of individual malts buffering, that is clearly something I should put on my list to address within a future update if I ever get sufficiently motivated to get around to it. But so far the deficiency in this area has not seemed to hinder the achievement of respectable results. For all of the above snapshots I merely used MME's internal defaults, sans for the one single change of overriding the 65L Brown malts default of 5.00 DI_pH by inserting along side it (in the manual override column) forum member cire's actual measured 4.51 DI_pH for same.

 

[cire]

Thanks for taking the time. This says the buffering is 90 or more. I have measured as high as 90 (on a Briess 80L caramel) but have only seen over that with sauermalz (as have others that I am aware of). So I'd be really interested in what the buffering is for this malt if you would be inclined to take another measurement (or 2). Given that it appears that the buffering must be nearly 100 mEq/kg•pH we'd need to absorb 10 mEq/kg to get the pH to rise by about 0.1 so that if you mashed 100 g (to get the required bicarb up to where you can measure it) you would need to add about 1 mEq's worth of absorber. This would be 84 mg of NaHCO3 (as it absorbs almost 1 mEq/mmol at pH 5.6).

OK, will the next test when time and other constrains allow.

The malt I have was bought from a reputable supplier as Brown Malt EBC 130. It is not in a 25kg bag nor certified in similar manner. I have no reason to suggest it is any other and believe it to be a product of Bairds.

Brown and Amber Malts from various maltsters have substantially differing EBC ranges, can and do overlap. In a brief web search, Crisp's brown malt is said to be 150 EBC while Simpson quote theirs as 430-600 EBC, the lowest EBC found for brown was 95 EBC with Amber typically 100 EBC. Bairds and Simpson's classify Amber and Brown Malts as roasted malts and not as highly kilned malts.

 

[dmcmillen]

I'm curious, how does the age of a malt affect its acidity assuming its been stored properly. I store my grains in 5 or 7 gallon plastic tubs with gamma lids.

 

[ajdelange]

I'm not at all confident that I've got the entire buffering thing fully down pat within the inner workings of MME. Rather in all honesty I would say that for the current edition of MME I do not at all have it right. But since you have been guiding and educating us as to the importance of the inherent variability of individual malts buffering, that is clearly something I should put on my list to address within a future update if I ever get sufficiently motivated to get around to it. But so far the deficiency in this area has not seemed to hinder the achievement of respectable results. For all of the above snapshots I merely used MME's internal defaults, sans for the one single change of overriding the 65L Brown malts default of 5.00 DI_pH by inserting along side it (in the manual override column) forum member cire's actual measured 4.51 DI_pH for same.

The approach of calculating default pHDI and buffering from color, type etc makes your approach as good as the other programs that do the same. Allowing the user to input an actual malt DI pH gives you a large advantage over them in cases like this one where a malt that doesn't fit into one of the major categories. But there is still more improvement to be had if you do the same for the buffering. Yes, the DI pH is the more important of the two and it sort of works out to use 45 for every malt because base malts run in that range and mashes are mostly base malt but there is still improvement to be had if you allow the user to input the actual buffering of his malt when things don't seem right with the default value.

 

[cire]

Thanks for taking the time. This says the buffering is 90 or more. I have measured as high as 90 (on a Briess 80L caramel) but have only seen over that with sauermalz (as have others that I am aware of). So I'd be really interested in what the buffering is for this malt if you would be inclined to take another measurement (or 2). Given that it appears that the buffering must be nearly 100 mEq/kg•pH we'd need to absorb 10 mEq/kg to get the pH to rise by about 0.1 so that if you mashed 100 g (to get the required bicarb up to where you can measure it) you would need to add about 1 mEq's worth of absorber. This would be 84 mg of NaHCO3 (as it absorbs almost 1 mEq/mmol at pH 5.6).

Well, I'm not used to micro-scale testing, but have double checked all operations and the highest pH recorded was 4.57 with 84mg of sodium bicarbonate in DI water with 100 g of my brown malt.

 

[ajdelange]

... but have double checked all operations and the highest pH recorded was 4.57 with 84mg of sodium bicarbonate in DI water with 100 g of my brown malt.

84 mg is 1 mmol which, at pH 4.57 absorbs 0.985 mEq protons and which, with an (4.57 - 4.52) = 0.05 pH shift using 0.1 kg malt implies a = 0.985/(.1*.05) = 197 mEq/kg•pH.

Well, I'm not used to micro-scale testing,...[/QUOTE[ Think of this as a check rather than a formal test. Were we to want a firm number for a we would take three or more 100g samples of this malt, add 0, 1, 2, 3, 4... mmol NaHCO3, to 100 100 mL DI water, put the samples in a water bath, add the water to the samples at two minute intervals and then, at 20 minutes measure the first sample's pH, at 22 measure the second and so on. This would give us a curve of mEq/kg vs pH and we would then fit a line (or parabola if it seemed justified) through the data to get our estimate of a. Note that I am not asking that you do this. You have shown that the buffering of this malt is much higher than normal and until someone wants to go out and do a fuller set of measurements that's going to have to suffice. I, for one, appreciate that you were willing to take the time to do this measurement and hope the other participants here do too.

 

[cire]

The producer of my brown malt was probably Bairds which is at the lighter end of the range available by UK Maltsters. That is lighter by colour most others, but not necessarily in terms of aroma, which is like that of a smooth chocolate. However, as chocolate from USA and UK are quite different I'm unsure if that description translates properly.

My tests were as advised which initially appeared practical. One kg of a typical grist in 2 litres of liquor produces a quite stiff mash (I usually mash with 25% more liquor) that would retain about a litre of liquor, releasing a similar volume of wort. However, in this case with all brown malt, very little wort was released and half the mashed grain remained in its container when upturned. In some of the tests it was necessary to squeeze the mashed brown malt to extract sufficient wort to cover the pH meter probe and believe this brown malt would require double the liquor volume suitable for pale malt or a typical beer grist to have a mash that would allow free flowing of liquor.

I would like to hear if others find similar with their brown malt.

 

[ajdelange]

Nothing wrong with the way you did the tests under the circumstances. Had you done both measurements on the same day there probably would be more consistency between them and that's what was behind my last post. Measurement is an art which one learns with practice. Your test showed that when you added bicarbonate in quantity that would cause a normal malt's pH to shift upwards by about 0.2 pH this malt only shifted by about 0.05. It, therefore, clearly has high buffering relative to most malts and that's what we were really interested in confirming here.

 

[dmcmillen]

Hope this is still being monitored. I've been out of touch for a while. I am ready to do my 2nd test mash with both grains (MO & Brown) and salts for this Porter. I know now that I'm not trying to match any profile like the ones in Bru'n Water but I do need to determine what levels I would like. Right now, for this recipe, I am trying to start from AJ's recommendations in his Primer Sticky. To recap from the beginning of this post, my water is Alk 98, SO4 9, Cl 4, Na 28, Ca 9, Mg 4. You can tell from my questions that I am still trying to get a better grasp on what I am actually trying to accomplish.

• AJ recommends in his Primer sticky to add a teaspoon of CaCl and skip the sauermalz for a Porter. Obviously wouldn't want any more acidity here because of the acidity of the Brown malt. Since the CaCl is most likely anhydrous, then that would be 3.6 g CaCl (vs 5g for the dihydrate). Now is that total for the mash water and the sparge water? I.e., do I need to divide that proportionately between the mash and sparge water? I'm trying to use Bru'n Water to calculate the equivalent of the added tsp of CaCl and to be able to scale down for the test mash.
• AJ's Primer Sticky indicates that you can use RO or DI water and only add CaCl. Then there would be no Mg or Sulphate. Is that ok? Are there really no minimum levels for some of the salts?
• I actually brew 6 gals of which 5.5 go to the fermenter. Should I scale the 5 gal recommendations up (the tsp CaCl, not Bru'n Water recommendations) or is that not important?
• My first test mash yielded a dipH of 5.15 for the Brown Malt. My 2nd test I wanted to do with both grains and salts. I fully expect to have to add some bicarbonate to get the pH up. Should I do the 2nd test with just the Brown malt to establish its buffering or can I do the next test with both grains and salts and go from there?
• AJ recommends starting with water that is either DI, RO or where Alk is < 35. For this brew I would think the high alkalinity would be ok, but for "normal" brews where I'm not dealing with a Brown malt, what would be better, doing a 2:1 DI dilution to bring the Alk down to the recommended < 35 level, or use DI water? This question is related to my lack of understanding of what mineral levels I'm trying to achieve.

 

[Silver_Is_Money]

You don't need magnesium for any beer, or sulfate ions for a porter. I generally adjust to 50 ppm of calcium in the mash water, and then do likewise in the sparge water, but you can optionally leave it out of the sparge water, or also optionally front load all of it into the strike water such that your total of strike and sparge water (if blended together) will come out to 50 ppm of Ca++ ions.

At this juncture it may be best to perform the test mash at the exact ratios of ingredients, water, and minerals as for your full scale recipe. That will tell you if the 98 ppm Alkalinity and the 50 ppm calcium will be sufficient to get you to 5.4 to 5.5 pH for the mash. I generally make an initial first guess at a need for about 70-80 ppm alkalinity in the strike water for a porter.

Based upon my tests of several batches of fresh and unopened CaCL2 prills, i'm guessing yours will be about 94% CaCL and 6% water when the package is first opened. You most likely will want to adjust both your strike water (mandatory) and sparge water (optional) to 50 ppm. You will be adjusting on the order of 9 gallons of water overall to 50 ppm Ca++, and not the 6 gallons you intend to end up with.

You will want to acidify your sparge water to a pH of 5.4 to 5.6.

 

[dmcmillen]

Thanks Silver!

I generally adjust to 50 ppm of calcium in the mash water, and then do likewise in the sparge water, but you can optionally leave it out of the sparge water, or also optionally front load all of it into the strike water such that your total of strike and sparge water (if blended together) will come out to 50 ppm of Ca++ ions.

Knowing that I would want to shoot for 50ppm Ca is relatively easy to achieve with one of the spreadsheets like Bru'n Water. I really didn't know what I was shooting for so I was using AJ's recommendation of 1 teaspoon of CaCl dihydrate as a starter. Since almost all of the CaCl purchased from the LHBS's is anhydrous which AJ established in his Primer Sticky, I was using 3.6g per teaspoon (5g of dihydrate), those amounts coming from the Sticky conversation. That raised the question is it a teaspoon per mash water or per mash and sparge water? Again, not knowing the Ca level I was trying to achieve, I was trying to back into whatever that might be by inputting the 3.6g of CaCl into Bru'n Water. That's a little trickier because of the way Bru'n Water works.

You will be adjusting on the order of 9 gallons of water overall to 50 ppm Ca++, and not the 6 gallons you intend to end up with.

Yes, the total water is about 9 gals to be treated with final of 6. My question was that if the recommendation is 1 teaspoon CaCl for a 5 gal batch and my batch is 6 gal should I adjust the amount of CaCl up accordingly or am I nit picking this too much. I suspect that the Sticky recommendations are general recommendations for someone who may not be using a meter or even a spreadsheet and wants some general guidelines.

Mostly I'm working on getting a "feel" for what I want to shoot for and how to achieve that.

 

[mabrungard]

Since almost all of the CaCl purchased from the LHBS's is anhydrous which AJ established in his Primer Sticky,

It might start out as anhydrous at the point of manufacture, but its probably picked up a little bit of water in the meantime. But AJ's observation is still valid. I prefer to consider my calcium chloride to be in the anhydrous form and perform my calculations with that assumption so that I don't overdose the water with that salt. Assuming that the salt is in its dihydrate form is more likely to overdose your water.