Alkalinity & Residual alkalinilty

Is there a certain ppm range that these should fall in .

Thanks Pat

Generally, the lower the better. For alkalinity, the limit is 0 whereas RA can be appreciably negative (alkalinity can be negative too but if it is the water is probably not fit for brewing though exceptions to that too are possible). Alkalinity is a measure of buffering capacity of the water i.e. it's ability to resist pH reductions by added acid as from malt. Residual alkalinity is the amount of alkalinity which has not been offset by hardness (which reacts with malt phosphate to produce acid and thus reduce mash pH). In brews except ones laden with dark malts it is necessary to add acid in some form to effect a desirably low mash pH. The more alkalinity the more acid will be required. Hence the general rule "alkalinity = bad". Since hardness offsets alkalinity (RA = alkalinity - hardness/3.5) I used to have the companion rule "hardness = good" but people got a little carried away with this thinking that 200 units of alkalinity was no problem if they simply dosed in 700 units of hardness (e.g. 1.2 grams of gypsum per liter of water) which led to some pretty crunchy beers. As evidence that the best beers are made with the softest water has mounted I have dropped that rule.

Now it is well known that many, if not all, beer styles evolved based on the available water it stands to reason that various styles were brewed with water with particular alkalinity/RA. The chart at
http://www.pbase.com/agamid/image/57446374
illustrates this. Here various brewing cities names are plotted against the reported local water's alkalinity and hardness. As RA = alkalinity - hardness/3.5 it is possible to show lines of constant RA on this chart as having slope 1/3.5. If a brewer is a real stickler for authenticity he can, guided by this chart, prepare, say, Vienna water for the purpose of brewing a VMO. However there is the question of how one gets to a particular alkalinity and hardness and thus RA. This is somewhat difficult involving dissolving chalk in base water using CO2 gas. Unfortunately many undertake this process ignoring the CO2 (how many spreadsheets have you seen that calculate the CO2 requirement) with results that are far from the targets (and the target data are frequently in error). Given that it is not necessary to do all this it is often simpler to just say that alkalinity should be 0 and RA around -30 (representing about 50 mg/L Ca++).

I agree with AJ, brewing water should have only the alkalinity needed to produce a decent mash pH and resulting beer pH.

I have to comment on the chart AJ has assembled. It includes several water profile results that are not feasible and there is considerable scatter in the results do to that. At AJ's suggestion, I included a version of that same RA chart on the Adjustment Summary sheet of Bru'n Water. With the cleaned up information on water profiles that I've compiled, I was also able to plot the water RA results for those various Cities. AJ's chart above does show some of the same results, you just can't see it.

The point I'm trying to make is that there are distinctive trends in the results that relate to those profiles with high temporary hardness and those with high permanent hardness. You'll need to download the current version of Bru'n Water to see what I'm talking about. High temporary hardness waters tend to plot on a relatively steep line within the chart, while the high permanent hardness waters tend to plot along the 1/3.5 lines that AJ mentions. All this doesn't really amount to a hill of beans, but I figured it was an interesting thing that brewers might not be aware of.

Enjoy.

Thank you both it nice to get answers from the" Rocket scientists" of water science. Btw Aj I'm sending in another sample to be tested I've had my softner off line for a couple weeks I will report the finding when I receive them.

Thanks again
Pat

Aj and Martin, I was talking to a friend about this post who works for a local water treatment plant and now has me a bit confused. Referring to the last line in Aj's reply (simpler to just say alklinity should be 0 and ra -30 ) so if I build my water on ez water and my numbers come out 0 alklinity and -30 ra
my water should be good correct.

Thank again
Pat

0 and -30 are desirable for a pale colored beer with little crystal malt, but may produce a sharper and tarter beer than desired if dark malts or crystal malts are in the grist. Just using those values will not suit all beer styles. That is why a tool like Bru'n Water is useful. It allows you to see the effect of the grist and helps you estimate what your water adjustments may be. The best tool will still be a pH meter, but Bru'n Water will consistently get you in the ball park.

lehr said:

.. so if I build my water on ez water and my numbers come out 0 alklinity and -30 ra
my water should be good correct.

Click to expand...

There's a bit more to it than that. Zero and -30 just happen to be the alkalinity and RA numbers for DI/RO water to which about 3 grams of calcium chloride have been added per 5 gallons treated. Such a water will, in most cases, make a good beer if the proper amount of acid (as sauermalz: 2-3% for light lagers; 1-2% for ales; none for stouts) is added. This is important as the most significant thing you can do to improve your beer is to get mash pH into the correct range. The details are in the Primer.

Has anyone explored the blending of calcium citrate with the traditional calcium carbonate to increase calcium solubility and dispersion in the mash. I am looking for a way to formulate and use a pill press to compact the mixtures so they can be automatically added to the malt before milling and addition to mash tun.

I'm not quite sure what you are thinking of here. If the goal is to get more calcium to dissolved you would use a soluble calcium salt such as the chloride or citrate (moderately soluble) but not in the presence of ions with which it forms insoluble precipitates such as carbonate and phosphate.

I am looking for an alternative to trying to carbonate calcium carbonate to increase the solubility. Calcium chloride is soluble but by the time the calcium target is hit the chlorides would be high. I would expect that the citrate component of the calcium citrate would drop Ph a bit and may be counter productive if a carbonate is not added to counter balance citrate acidity.
The initial goal is come up with a way to integrate water chemistry control into the brewing system formulation and process control application that I am working on for my system. The methods and formulas are not difficult, and implementing them was a matter of creating a couple tables and some calculations, just curious if there were any others that have explored this avenue of calcium addition without resorting to brew time chemistry experiments with CO2.

For each meq dissolved calcium you must have 1 meq of some anion. The choice is pretty much yours. However with nature that anion is largely bicarbonate (with sulfate and chloride being the others). The problem is that you cannot buy calcium bicarbonate so you must make it as nature does and that involves carbon dioxide gas. I'm not sure where your "targets" are coming from but if they are published profiles for brewing cities and valid (a big question) then you can only hit them closely by using carbonic. There is no way to match, say, Burton, water without it. If you decide you want the calcium of Burton water without the bicarbonate then you are not matching Burton water but rather just the calcium of Burton water and some anion, be it lactate, citrate, phosphate, chloride, sulfate, phosphate will have to be there in place of the bicarbonate.

As there is generally no point in trying to match particular water profiles (you can usually make a better beer by not doing that with the exceptions being Pilsen etc) it seems a lot of trouble to go to with little expectation of improvement. If your goal is to see what a genuine Burton ale tastes like as brewed with genuine Burton water then you would have to do the CO2 thing.

The water supply for the brewing system is almost softer than Pilsen water profile, the CO2 method is easy enough to do, just looking for a method to do the water profile tuning with dry materials. Might be better to approach this from a aqueous solution addition direction instead of trying to do dry materials, control of liquid additions would be a bit more complicated though. For the most part this a make work exercise to burn up down time on the weekends by writing additional features into the brewing system control software.

After spending some time testing the various formulas against the popular water calculation spreadsheets it looks like what I expected is not the same as the applied methods. Calculations for RA tracked with the data presented in the various table entries and calculation spreadsheets, but not when the published formulas presented for all the components in water profiles were used together. I am curious as to which water components are needed to calculate the RA and which to ignore.

Residual alkalinity is defined by

RA = alkalinity - (Ca_hardness + Mg_hardness/2)/3.5

Thus the only ions you need to consider in calculating it are

Calcium
Magnesium
Bicarbonate
and
Carbonate.

Hydroxyl ions also contribute to alkalinity for waters of higher pH.

Strictly speaking you need to consider all charged ions in the soup (fluoride, chloride, iron, nitrate, sulfate....) because these effect the activity coefficients of calcium, magnesium, bicarb and carb but the effects are, for brewing water, small enough that these can be ignored. The error introduced is less than that which is associated with not really knowing what the definition of alkalinity is. The lab is required (per Standard Methods) to tell you what pH was used for the end point of the alkalinity titration but I've never seen a report that actually does that.

The problem with the spreadsheets seems to be that they try to extend the concept of RA to mash as well as water. RA was not intended for this but if you can calculate the RA of water with lactic acid added why not for water with the acids contained in malt? The answer lies in the fact that the concept of RA relies on the idea that malt phosphates will react with calcium and mangnesium to release protons and thus acidify the malt (this is where the 1/2 and 1/3.5 factors come into it). The other big problem with the spreadsheets is that they do not calculate alkalinity correctly where bicarbonate or carbonate are involved (or additions of other weak acids such as phosphoric, lactic, citric etc). One can get away with this to a certain extent as long as pH is below 8.3 or so.

One must remember with respect to RA that its value is pretty much limited to comparison of water supplies. The 1/2 and 1/3.5 factors are nominal. Computer simulations of the chemistry of phosphate/carbonate systems shows that these numbers are only realized when certain assumptions are made about the amount of inorganic phosphate released by malt. The same goes for the tie in between RA and knockout wort pH, no not mash pH, knockout wort pH (see Kolbach's original paper at www.wetnewf.org). Again, typical values can be computed but they are for base malt only mashes and, as the brews studied were German, presumably the base malts were Pilsner malts.

Thank you for the explanation and the link, it has helped immensely in my understanding of the formulas and chemistry involved, and their relationship. The acidification with dark malts brings up the question of using acidulated malt and the corresponding effect on SG, color, and mash volume when it is added for PH correction. This should be an interesting Ph correction scenario to work out, versus simple acid addition to brewing water, enough to keep me busy for a while working on the formulas and mechanics of this.

After some work with the various equations it seems that things are working correctly when the various higher mineralized waters are used. It appears that when there is insufficient calcium and the mash acid value increases the PH changes opposite the direction expected. Have I implemented the wrong formulas or is this just the expected result when residual alkalinity is low.

You haven't given me enough to understand your question fully. If you are speaking of the effects of calcium on phosphate containing malt there are 10 simultaneous equations (1 for CO2 partial pressure, 1 for each of the two dissociations of carbonic acid, 1 for calcium carbonate solubility, 3 for the dissociations of phosphoric acid, 1 for calcium phosphate solubility, 1 for charge neutrality and 1 for proton condition) which must be solved and a lot of assumptions must be made. There is no closed form solution for these. OTOH you can get a rough idea of what it going on using Kolbach's RA definition and his observation about pH shift per unit of RA. I assume you mean the latter. This assumes there is an excess of phosphate and should show a decrease in pH whenever calcium is added or bicarbonate reduced (reduced RA) and an increase of pH when calcium is reduced or alkalinity increased (increase in RA).

Can you be more specific as to which equations are giving you suspect results?

Here are the equations that I am attempting to use with interesting results in certain situations.

Alkalinity as CaCO3 HCO3 (ppm) Divide by 61 and multiply by 50

RA* = Alkalinity (ppm as CaCO3)* -* 0.714 x Ca (ppm)* -* 0.585 x Mg (ppm)

Roasted malts: AA = 42.3 x Wt

All other malts: AA = 0.356 x Wt x (Lovibond - 1.8)

mash RA = -1.2 + TAA / MWV

pH =* 5.8 +*((.013*mash Ra)+.013) x RA

This seems to work well with harder water than what I am using, as the municipal water source is filtered river water.

Water Quality
units Results
pH SU 7.48
Chloride mg/l 3
Copper mg/l 0.011
Silver mg/l 0.0004
Zinc mg/l 0.05
Calcium mg/l 3.39
Alkalinity mg/l 20
Bi-Carbonate mg/l 16.4
Calcium Hardness mg/l 10.2
Chlorine Residual mg/l 1.3
Hardness mg/l 10.7
Potassium mg/l 0.655
Silica mg/l 12.9
Sodium mg/l 8.3

Thank you for your patience and help with this.

AH, OK. Here I step back and say that while there may be a correlation between malt color and its acidity that correlation is so weak (low values of Pearson's r) that malt acidity is not predictable from color. Second, acidity must be expressed as a function of pH - it is not a constant (titration curve). Third, base malt DI mash pH is not a constant but depends on the base malt (while it is around 5.75 for pilsner base malts it is more like 5.6 for pale ale malt). Fourth as RA is defined in terms of how much malt phosphate neutralizes water alkalinity RA for a mash is meaningless. Thus, I don't believe that mash pH can be modeled this simply. I recognize that one could potentially do this if he had titration curves for each malt in the grist but that data is impossible to obtain unless one wants to do the titration on each malt and it is, IMO, much simpler and useful to just take a small portion of the grist, add some water and measure the pH.

The particular equations you have listed represent a model of mash pH as a function of water RA and malt color. Sometimes the model fits what you see in real life. Sometimes it doesn't. That's the best expalantion I can offer as to why you get erratic numbers. All models have their limits and if you go outside those models often collapse, sometimes violently.

Thank you for the confirmation of my suspicions, if it looks to good to be true, it probably is not true for all conditions. You mentioned the phosphate extraction from the malt as an alkalinity neutralizer/binder, what would the effect be if the yeast nutrient ammonium phosphate were added to alkaline brewing waters.

That would depend on the calcium content. If that were high enough, the pH high enough and enough DAP added to raise the total phosphate level sufficiently apatite (calcium hydoxyl phosphate) would precipitate just as it does with the phosphate from malt. But malt contains as lot of phosphate - almost 2% by weight. As yeast nutrients seem to be used and the fraction of a tsp per 5 gal level and contain things in addition to DAP I'm guessing that in most cases there wouldn't be enough phosphate added to stimulate precipitation.

Well we brewed this weekend built our water from my friends water hit all our number using ez water and borrowed a ph meter, our mash ph was 5.3.
All of our gravity readings pre boil and post boil we dead nuts and it was fermenting like crazy the next morning.

Thanks for all the advice.

Pat

Hopefully you guys are still watching this one. I have not been very pleased with my beers lately. I have been getting a harshness/astringency. I really like the idea of using my own water without having to buy a RO system or haul water.

I have a total mental block when it comes to chemistry but I know I need to learn some of it to make good beers. I have never considered the Alkalinty=0, RA=-30. I brewed a beer recently that I was not very happy with. I just changed the additions (only lactic) which gets me in the suggested ALK/RA range. Anybody see any problems with this? It almost seems to easy.

Starting Water (ppm):Ca:31.9Mg:13.9Na:2.6Cl:4.1SO4:14.4CaCO3:123Mash / Sparge Vol (gal):4.84/12.2RO or distilled %:0%/0%Total Grain (lb):15.5Non-Roasted Spec. Grain:4.5Roasted Grain:0Beer Color (SRM):2.8Adjustments (grams) Mash / Boil Kettle:CaSO4:0/0CaCl2:0/0MgSO4:0/0NaHCO3:0/0NaCl:0/0CaCO3:0/0Lactic Acid (ml):2Sauermalz (oz):0Mash Water / Total water (ppm):Ca:32/32Mg:14/14Na:3/3Cl:4/4SO4:14/14Cl to SO4 Ratio:0.28/0.28Alkalinity (CaCO3):-5RA:-36Estimated pH:5.55

Ok....SO I just did a water profile using BrunWater. I am very new at this.

In my calculations I got in Brun Water it calculated I would have a 5.3 pH a hardness of 132 and an Alkalinity of -2.....so is my -2 alkalinity bad? Should I have added more of a mineral to up that? I used RO water and added 1.4 grams of Gypsum, 3.7 grams Calcium Chloride, and .7 mL of Lactic Acid.

In the water adjustment all the rows of the "finished water profile" turned green except the Bicaronate one.

All mashes require acid in order to reach a desirable pH. Some grists provide that acidity, but in the case of pale grists, the acidity has to some from either salt or an actual acid addition.

When an actual acid is used in the mashing water, it can consume all the alkalinity in the water and drive the water's pH below 4.5. For that reason, Bru'n Water refers to that excess acidity in terms of a 'negative' bicarbonate or alkalinity value. It is OK.

So what you are saying is that I didn't completely screw it up lol. Are the values I got bad? Or do you think I should have aimed for a little higher values? I just used the water primer last time for a stout I did. This time I was doing an Irish red and just kind of winged it. All I know is I wanted it a little more malty so I wanted the chloride higher than the sulfate....my understanding from the primer is malty = more chloride and more hops/bitterness= more sulfate.

The primer tries to dispel the concept that more chloride equates to more malt and more sulfate to more hops.

More to the point you were correct in perceiving the a negative bicarbonate number represents a flaw in the software. Alkalinity is the amount of acid that must be added to a solution to bring its pH to 4.5 so that if its original pH is < 4.5 clearly acid must be withdrawn and the alkalinity is, in such cases, negative. However, even when alkalinity is negative bicarbonate is always positive - very small and positive but positive none the less. A water sample with alkaliity at 1.65 at pH 7 would have, upon acidification to 4.4 i.e. the point at which it's alkalinity has been reduced to 0, a bicarbonate content of 1.3 mg/L. As the pH drops into negative alkalinity territory to the extent that the pH reaches 4.2 the bicarbonate content is still 0.84 mg/L.