Mineral loss from mash to kettle? Mash and kettle additions?

[jkiv]

Hey all,

I have some questions and concerns about my water chemistry and/or water treatment process, and I haven't been able to find any solid answers via search. Anyway...

I currently treat my relatively soft, relatively alkaline water with salts and lactic acid in the mash. I treat my sparge water with acid only, as I have a limitation with my brewing setup. I get about 85~88% efficiency, so I end up sparging quite a bit to hit my target kettle gravities. I use Bru'n'Water (supporter edition) to estimate my additions and final beer mineral content based on a fairly regular water report. So, my problem is that I'm finding that my beers tend to taste more watery (less crisp/hard/mineraly) than I'd expect based on the mineral content estimation. I have not yet had my beers tested for mineral content.

I was listening to a podcast (see below) where the brewer being interviewed mentioned only 40% of calcium additions from the mash make it to the kettle. First, is this true or well known? If so, does Bru'n'Water take this into consideration when all my salt additions are added to the mash? Might this explain the lack of hardness due to my process?

Lastly, and less importantly, is there a way in Bru'n'Water to specify both Mash+Sparge and Kettle additions? I can see Mash+Sparge only, or Kettle only.

EDIT:
Since I can't link to youtube, here's the interview. She makes the particular comment around 20m 05s.

 

[Horseflesh]

I heard the same comment, and would have started this thread myself eventually.

 

[bitteritdown]

AJ, Martin and Kai comment on this subject in this thread:

https://www.homebrewtalk.com/forum/threads/is-the-calcium-in-mash-water-lost.353514/

 

[jkiv]

Thanks, bitteritdown.

I suppose since Martin isn't sure whether Ca loss is constant or proportional to the initial Ca concentration that it probably isn't accounted for in Bru'n'Water.

I'll continue to look at possible solutions and let everyone know what worked for me.

 

[cire]

Thank you jkiv, that was an excellent podcast, amongst the best by Brad Smith in my opinion.

As can be seen at the following link, a paper at the same time of my early homebrewing and drinking days, a mark in the margin highlights the section on calcium losses.

http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1963.tb01933.x/epdf

The paper was from USA, but calcium losses were of more in UK where most beers of that time were ales of between 3 and 4% ABV. Exceptions were few, and therefore the amount of calcium and its attendant sulphates and particulary chlorides were a vital part of producing lower alcohol yet satisfying beers.

Figures that come to mind are of a mash of distilled water with malt that provided a level of calcium equivalent to 40mg would provide no more than 24mg/L into the kettle. Calcium is vital in the kettle, at low levels copper finings do not perform their function efficiently. The other side to the coin is that many lagers are the product of low calcium level liquors.

In a list of more than 100 beer analyses, the majority with lower than 20mg/L calcium in the finished beer were made in either Australia or USA, typical levels of beers made in Germany and other central European countries were typically 50mg/l, while those with >100mg/L were produced in Belgium or UK. From these it is possible to approximate starting values. The podcast emphasised the importance of getting the correct ingredient levels, including minerals if producing so called session ales.

Sadly, here in UK most new craft brewers are unable to produce sub 4% ABV ales as satisfying as were widely available fifty years ago.

 

[mabrungard]

Since calcium loss via precipitation and adsorption are variable, it would be folly to try and predict it. Bru'n Water does not incorporate those losses in its estimates.

The 40% estimate for calcium making it into the kettle sounds a bit off to me. That seems to be a higher loss than I've seen. But I'm sure there are conditions where that result is possible.

Another issue that brewers should understand is that redirecting the salt additions from the mash to the kettle is NOT LIKELY to result in a significantly different result. The calcium/phosphate precipitation reaction takes place equally in the mash or kettle. Delaying your calcium salt additions to the kettle just means that the precipitate ends up in the kettle trub instead of the mash bed.

While high calcium content in brewing water does enhance some aspects of the processes, there is little need for high levels. The main improvement is in ales where higher calcium level enhances beer clarification. In lagers, that effect and inhibitions to metabolism are important reasons to keep calcium levels much lower than for ales.

50 ppm Ca is adequate for ales. There is no need to increase that excepting as needed to add sulfate and/or chloride for flavor effects. For lagers, keeping calcium levels at 40 ppm or LESS is proven to improve the beers and yeast metabolism.

 

[brewing_clown]

50 ppm Ca is adequate for ales. There is no need to increase that excepting as needed to add sulfate and/or chloride for flavor effects. For lagers, keeping calcium levels at 40 ppm or LESS is proven to improve the beers and yeast metabolism.

I find that I have clarity issues if I go below 80ppm. Not so important with lagers, but definitely a problem with ales. I'm at 7,000 feet and my boil is 94C, so that may be part of it too.

 

[cire]

Since calcium loss via precipitation and adsorption are variable, it would be folly to try and predict it. Bru'n Water does not incorporate those losses in its estimates.

The 40% estimate for calcium making it into the kettle sounds a bit off to me. That seems to be a higher loss than I've seen. But I'm sure there are conditions where that result is possible.

Wouldn't also be folly to ignor such losses and to soldier on in contempt of any obvious implications. A very well known beer beginning with "B" was analysed and found to contain 8mg/L calcium and 70mg/L magnesium, which would seem to fit with the 40% and its well advertised ingredients.

Another issue that brewers should understand is that redirecting the salt additions from the mash to the kettle is NOT LIKELY to result in a significantly different result. The calcium/phosphate precipitation reaction takes place equally in the mash or kettle. Delaying your calcium salt additions to the kettle just means that the precipitate ends up in the kettle trub instead of the mash bed.

Agreed, except there are reactions with calcium in the kettle that cannot and do not occur in the mash tun and therefore calcium additions to the kettle are essential if only sufficient calcium is added to the mash tun soley for those reactions and to achieve a desired pH.

While high calcium content in brewing water does enhance some aspects of the processes, there is little need for high levels. The main improvement is in ales where higher calcium level enhances beer clarification. In lagers, that effect and inhibitions to metabolism are important reasons to keep calcium levels much lower than for ales.

50 ppm Ca is adequate for ales. There is no need to increase that excepting as needed to add sulfate and/or chloride for flavor effects. For lagers, keeping calcium levels at 40 ppm or LESS is proven to improve the beers and yeast metabolism.

Higher calcium additions will cause havoc with Pilsner and several other styles as they also do to many pH predictive softwares. As with calcium losses, many factors are at play than simple calculations take into account and greater amounts of calcium can sometimes increase variability.

I'll agree with your <40 and 50 ppm Ca in theory, but the upper figure leaves no margin for losses which you rightly advise are not readily predictable and what might work one day for an ale brewed with 50ppm Ca will probably fail many times over before being again sufficient.

It is so much easier to brew ales with sufficient calcium to be present for every mash tun reaction, in the kettle for depositing break and in the FV to aid yeast flocculation to produce a bright beer EVERY TIME. More calcium is balanced by slightly more alkalinity which acts as a buffer in the mash tun producing a more consistent and stable pH and when in the boil is deposited if it natural or calcium based to help reduce pH to make a beer with better shelf life. (This drop in pH will not happen with sodium based alkalinity additions.)
Of course this is not the route for making lager nor for ales with no firm malt flavors, but if you have the appetite for bright flavorful ales without fining and within three weeks of the brewday, trying some higher amounts calcium salts in the mash and the kettle is easier than pondering over diverse opinions on Brewing Forums.


@ brewing clown, I'm at 200 feet asl and would struggle to ensure every brew would be bright with just 80 ppm Ca with variation in quality of the vast array of commercial malts from different strains and different maltsters. My standard mash liquor for a pale beer has 95 ppm Ca liquor as does the sparge. Extra calcium salts can be added dependent upon the flavors desired. As said, using 50 ppm Ca would require the beer to left much longer to clear, as for lagers, or use finings which with more calcium is totally unnecessary.

 

[ajdelange]

More calcium is balanced by slightly more alkalinity which acts as a buffer in the mash tun producing a more consistent and stable pH

Whenever I see a statement like that (and I see them fairly frequently) I object because while alkalinity does have a buffering effect it is not a buffer at mash pH in the usual sense. The graph below shows the buffering power of the carbonic/bicarbonate/carbonate system. Most of the alkalinity in brewing water is, except under unusual conditions, attributable to this system. While the curve shows that this system has buffering power at mash pH it has about 3 times as much at the pKs of carbonic acid (6.38 and 10.38). When we prepare a buffer in the laboratory with the intention of producing something that holds and stabilizes pH we choose and acid system that has a pH as close to the target as we can reasonably get. The curve shows that the carbonic acid system is good for making buffers at pH 6.38 and 10.38. In fact the buffer we buy for calibrating our pH meters at pH 10 is a bicarbonate buffer. It is not a good buffer at mash pH.
The other problem with statements like this is that the implied extra added alkalinity is gone (or 90% of it is) at mash pH (5.4 for 90%) after reacting to come to mash pH, being heated and stirred etc. Thus if you add 1 mEq of alkalinity as bicarbonate it would give you 0.2 mEq/pH buffering if it stayed but given that is doesn't, only 0.02.

 

[jkiv]

Wow, thanks everyone for the info.

I'm currently targeting (approximately):

* Mash pH of 5.24
* 120ppm Calcium in the mash
* 70ppm Calcium in the final beer
* 100ppm Sulfate in the final beer
* 75ppm Chloride in the final beer

I do have clarity issues with my beers, and those that do are about the same level of calcium in the mash (>100ppm), as I do all my mineral additions in the mash. I'm currently attributing the lack of clarity to other aspects of my process that may need refinement (vorlauf, yeast, etc.)

That being said, I've been poking around and came across some discussion about how low mash?/wort?/beer? pH can also contribute to a perceived wateriness. This might certainly be playing into the issue too.

I just recently started using acid (lactic acid) to treat my sparge water after I found that I was sparging about the same volume as my mash (due to high efficiency) and was getting a grainy/husky flavour in my lighter beers. I played with sparge volumes, temperature, etc. but it was not until acidification that the issue went away. At the same time I started using acid to treat my mash water, using less salt as a result, to keep Ca levels down. For the beer in question, I recorded a 5.24 mash pH. So, it might be entirely possible that a higher mash pH could help as well.

At first it seemed like perhaps adding salts to the kettle may reduce the thin/watery character of my beer (or at least enhance the mineraly-ness of the beer) -- but it has been suggested that this may not have the desired effect.

If it is more plausible that perhaps my mash/wort/beer pH is too low, then I can look into raising my mash pH.

I may go back to salts-only mash pH adjustment and aim for a higher pH, and continue to treat my sparge water with lactic acid.

Thoughts?

 

[mabrungard]

While calcium is subject to sequestering in the mash and kettle from precipitation, chelation, and adsorption, the flavor ions: chloride and sulfate are much less likely to be removed from the wort. They survive from the water all the way into the fermenter since they are highly soluble ions.

 

[ajdelange]

Careful on the terminology. Ions, in solution, are solvated for sure but sulfate is not very "soluble" in the presence calcium and even less so in the presence of barium. Chloride is not very soluble in the presence of silver. While we hope that no one will find barium or silver in his beers the point is that you can talk about the solubility of a salt but not of an ion.

 

[SleepyCreekBrews]

Here's a related question , is it better to add your water additions to the HLT, or to the MT while doughing in?
My thought is that the low PH of the mash may better dissolve the minerals and lead to less fall-out.

 

[ajdelange]

You shouldn't be adding any salts to your mash water that have solubility that is dependent on pH. At one time it was fashionable to add teaspoons full of chalk to mash based on the observation that this much chalk would not dissolve in the water and the theory that the acid from the malts would dissolve it. We now know much better than to add chalk to our beers at all. The other salts are all neutral or near neutral (thinking of sodium bicarbonate but it is very soluble at any reasonable pH). In any case, once the salts are dissolved the reactions will take place wherever solvation occurred.

There is a reason for dissolving salts in the water rather than the mash and that is that it is difficult and time consuming to get them thoroughly dispersed by adding to the grist or mash. If dissolved in the water they are as uniformly dispersed as you have been able to uniformly dough in.

 

[mabrungard]

Careful on the terminology. Ions, in solution, are solvated for sure but sulfate is not very "soluble" in the presence calcium and even less so in the presence of barium. Chloride is not very soluble in the presence of silver. While we hope that no one will find barium or silver in his beers the point is that you can talk about the solubility of a salt but not of an ion.

OK, now you're being silly. At the concentrations most brewers target, sulfate and chloride are highly soluble, meaning that they will not precipitate, adsorb, or exit solution via another mechanism. Semantics.

 

[ajdelange]

What is silly is to speak of the solubility of an ion (implied in #11 and reinforced in #15) at all as the solubility only has meaning when one proposes to dissolve some substance in a solvent. As one cannot buy a jar of ions one cannot reasonably design an experiment to see how much of some ion dissolves in a liter of water.

You can dissolve a bunch of calcium chloride in water. I often dissolve about 35 grams in water in each of two Falcon tubes to make 35 mL of solution because my HLT is 36" high. Filling the tank and adding the solution in one tube sets my desired concentration and then adding one cc from the second tube for each additional inch of RO water added to replace that drawn off maintains that concentration. If one believed in ion solubility he would conclude that calcium and chloride ions are both highly soluble. But try the same trick with calcium sulfate and see what happens! Obvious conclusion would be that neither calcium nor sulfate ions are very soluble. There is, of course, in fact no conflict as reasonable people understand that the solubility of these salts depends in the bond enthalpies of the compounds and that depends on both atoms. Now you can say that some metals tend to form salts that are more soluble than the salts formed by others. And you can say that calcium tends to form, in the brewing context, salts (including metallo organic ones) that are less soluble than the same salts formed by magnesium, sodium and potassium. And you can say that sulfate tends to form less soluble salts with calcium than does chloride but to say that calcium ion and sulfate ions are less soluble than sodium and chloride ions is folly.

In the hope of making this clearer lets note that precipitation of a salt occurs when

[Concentration_of_anion]*[Contration_of_cation] < solubility_product_of_salt

Technically, this is only for salts like NaCl where there is one of each anion. For something like CaCl2 the cation concentration would be squared. The important thing here is that the solubility is determined by solubility_product_of_salt
You can look that up in a handbook but you can't look up solubility information on calcium or chloride because there isn't any.

This is what I want people to understand. Easy to accuse me of nitpicking over semantics but I want people to understand this.

 

[ajdelange]

I was listening to a podcast (see below) where the brewer being interviewed mentioned only 40% of calcium additions from the mash make it to the kettle. First, is this true or well known?

It is certainly well known. Many brewing calculators and spreadsheets rely on Kolbach's observation that 3.5 mEq of calcium cancel 1 mEq of alkalinity. From this we can WAG (but it is going to be a WAG) the amount of calcium precipitated in the mash tun. The reaction is

10Ca++ + 6H2(PO4)- + 2H2O ---> Ca10(PO4)6(OH)2 + 14H+

Thus each 14 mEq of hydrogen ions (which neutralize 14 mEq of alkalinity) produced requires the consumption of 20 mEq of calcium. But the production of each mEq of hydrogen ions requires, according to Kolbach, that 3.5 mEq of calcium be present in the solution so that to get 14 mEq H+ we would need 14*3.5 = 49 mEq of calcium of which 20 would be sacrificed leaving 29 which is 100*29/49 = 59% of the original.

Now the phosphate isn't the only calcium binding ligand in mash/wort. Phytate itself and even some proteins will do this as well and we see further pH reduction from this in the kettle consuming more calcium. At the same time lets remember that malts do contain some calcium. So I do think it possible that as much as 60% of the calcium in the liquor could wind up as trub. But once the mash and boil are done the calcium has done many of it's jobs (enzyme temperature protection, pH reduction, bright runoff....) and there isn't really need for much at this point except for oxalate precipitation which we want to prevent gushing and to be sure that calcium oxalate precipitates in your fermenter (where it is a PITA) rather than in you kidneys where it is an even bigger pain, but this time literally.

The general rule of thumb is that your liquor should contain 2.5 mEq/L Ca++ (50 mg/L) but this is, demonstrably, much more than is needed for lager beers at least where lagering does some of calcium's assigned work. In ales you might want to have at least that much or more.