Adjusting water chemistry "on the fly"?

I apologize if this has already been posted before, but I couldn't find any pre-existing posts that directly addressed it...

I just used the Bru'n Water spreadsheet for the first time for an upcoming mash, and thought I had everything dialed in (using Pickling Lime to raise my mash pH for a dark brew, since Chalk is reportedly not so good for this).

But then I saw another post that I should wait until after dough-in and check pH after the mash balances out prior to adding any lime, because it could make the strike water pH skyrocket without the acidic grain present to buffer it.

If I test the pH and find that I don't need to add the lime at all (or just less), then my Calcium and Bicarbonate levels are going to be much lower, and wouldn't that affect my desired flavor profile?

And if that's the case, do I then add appropriate amounts of Baking Soda & Calcium Chloride to make up for those deficits? If so, when do I add those? Is it okay to add them to the mash, or will that throw off my mash pH? Or am I good to go with no further adjustments?

Maybe I'm missing something. Thanks for any help anyone can provide.

If any alkali is required then it should be in the water so that it is evenly dispersed and ready to go to work as soon as water hits grain. You don't care if the water pH skyrockets.

It is, however, unlikely that alkali will be required except in unusual cases even for a lot of dark beers. Thus if you have a formulation that requires alkali (bicarbonate, lime, chalk) be suspicious. The best thing to do is to take about a half pound of your grist (make sure it is well mixed) and add a half quart of warm water with all the salts you intend to use, stir thoroughly, set in another larger pot of warm water, continue to stir, allow to sit 15 minutes, stir again, withdraw a small sample, cool to room temperature and check pH. If, indeed, that alkalinity is really needed the mash pH will be about right. If it is too high then the alkalinity was not needed or less was required than you used. Run the test again with no alkali. If your pH is OK this time that confirms that no alkali was required. Do the mash without any. If it has fallen too low then use interpolation to determine how much alkali to use. For example if you got pH 4.4 with no alkali, 4.7 with and wanted 4.5 use 1/3 of the original alkali amount as 4.5 is 1/3 of the way between 4.4 and 4.7.

If you find that you don't need alkali do not be concerned about the reduced amounts of calcium, sodium or bicarbonate. None of these has a major flavor effect.

If you find you do need alkali try to get it all from sodium bicarbonate. Lime often turns out to contain a large proportion of calcium carbonate. If you must use lime add it as 'Kalkwaßer', a saturated solution of lime. Place a couple of tbsp of lime in a jar with a lid, add about a liter of water and shake vigorously. Allow the mixture to settle and clear. Each liter of the liquid will contain (at 20 °C) 1730 mg of Ca(OH)2 which is 46.7 mEq (IOW it's 0.046N - not very strong). Were you, as an example, to mash 8 lbs of Crisp Maris Otter with 2 lbs of Briess roast barley, with 3.5 gal of water with calcium hardness of 6 mEq/L (300 ppm as CaCO3) you'd have a mash pH of about 5.05 pH. This would be a case where you would indeed need some alkali, in fact 90 mEq of it to hit a mash pH of 5.4. If you wanted to get all this from lime you would need 90/0.0467 = 1927 mL. This, of course, scales down for the test mash.

Thanks, this is helpful.

So, what I'm gleaning from this in lay terms (aside from the partial grist test) is: go without the Lime, see what the pH is after the grain has a chance to balance out (chances are it'll be okay), if it's good, leave it alone and the flavor will be fine. If the pH is low at that point, then use an appropriate amount of Baking Soda to get the pH up.

Our water here is relatively low on minerals (runoff), so increasing the calcium and bicarbonate levels was an attempt to match a geographic water profile for the area from which the beer my recipe is cloning originates from (specifically, using the "Black Malty" profile on Bru'n Water). But you're saying an outcome where these minerals are elevated should be viewed with suspicion. Is trying to mimic a water profile the wrong approach?

I've often reserved the alkali addition in my mashes to see if they were actually needed. In almost every case, my mash pH hit the pH that Bru'n Water said it would WITHOUT the alkali (pH too low) and the precalculated alkali addition brought the mash pH to where it was intended to be. So, go ahead and know the amount of alkali that you are likely to need and reserve it if you have a good pH meter. Check the pH and add the pre-measured alkali if the reading is too low. Do NOT add alkali without knowing what the dose should be. You are likely to overshoot that addition.

AJ, I'm curious why you are recommending Kalkwater when it is the same thing as pickling lime? From what I can tell, the dry form is just as likely to suffer from impurity as pickling lime does. Are you recommending a liquid form and is that more sure in its alkalinity content?

DrewBlue said:

So, what I'm gleaning from this in lay terms (aside from the partial grist test) is: go without the Lime, see what the pH is after the grain has a chance to balance out (chances are it'll be okay), if it's good, leave it alone and the flavor will be fine.

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I can't, unfortunately, tag on that last phrase. The pH will be right (or very close to it) in the real mash. Flavor tuning is something you will have to do.

DrewBlue said:

If the pH is low at that point, then use an appropriate amount of Baking Soda to get the pH up.

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See if you can get it with baking soda. Obviously the thing to be concerned about is elevated sodium. There is, of course, no reason why you can't get it with Kalkwaßer but that is a bit of a PITA relative to sodium bicarbonate.

DrewBlue said:

Our water here is relatively low on minerals (runoff), so increasing the calcium and bicarbonate levels was an attempt to match a geographic water profile for the area from which the beer my recipe is cloning originates from (specifically, using the "Black Malty" profile on Bru'n Water).

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Home brewers used to be ruled by the notion that to brew beer that was like a beer brewed in Munich you had to have water that resembled the water of Munich. This notion has largely been put aside. The character of some styles is indeed at least in part attributable to the local water properties (for example Bohemian Pilsner should be brewed with very soft water which resemble that of Pilsen or Ceske Budijovice and Burton ales with gypseous low alkalinity water) but it is not necessary to match any particular Burton well. Just have low alkalinity and high sulfate. You ultimately must tweak the sulfate to get the beer you want but for starting out it is often a good idea to use low mineral water with a modest amount of calcium chloride and sulfate.

DrewBlue said:

But you're saying an outcome where these minerals are elevated should be viewed with suspicion.

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No, I'm saying you should be suspicious of any spreadsheet, program or calculator that advises adding alkalinity (bicarbonate, lime, chalk) to water or mash as it often isn't necessary or desirable. These programs use crude models of malt acidity which don't always accurately reflect the materials you are actually using. Then there are programs which use refined models but don't have actual data on the materials you are using. In either case, and especially with dark beers, there is the chance of appreciable error. That's why, especially with dark beers, the test mash approach is so valuable.

DrewBlue said:

Is trying to mimic a water profile the wrong approach?

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Not if you don't take it too seriously by which I mean strive to match the ion profile of the target to 1% for each ion. Getting the ion profile of the brewing water just right is something that you will have to do but you will, as noted earlier, have to do a lot of experimenting to find that as it depends on your personal tastes and what you are shooting for. You may find, for example, that a Pils made with lots more chloride than the traditional water is to your preference because it sweetens the beer. You may not. You may find that ales with 50 ppm sulfate are preferable to those with 300. You will find both camps right here on HBT.

mabrungard said:

AJ, I'm curious why you are recommending Kalkwater when it is the same thing as pickling lime? From what I can tell, the dry form is just as likely to suffer from impurity as pickling lime does. Are you recommending a liquid form and is that more sure in its alkalinity content?

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The assumption is that 'lime' from whatever source will (perhaps simply because of long storage) contain a fair amount of CaCO3 which we'd prefer to keep out of our mash. When a mixture of CaCO3 and Ca(OH)2 is mixed with water some (173 mg/100 cc @ 25 °C) of the lime but very little (1.3 mg/100cc) of the chalk will dissolve. Thus making the Kalkwaßer separates the lime from the chalk. And I guess knowing that the strength of the solution is 0.05 N without knowing anything about the purity of the starting powder and without having to weigh anything is handy.

ajdelange said:

Not if you don't take it too seriously by which I mean strive to match the ion profile of the target to 1% for each ion. Getting the ion profile of the brewing water just right is something that you will have to do but you will, as noted earlier, have to do a lot of experimenting to find that as it depends on your personal tastes and what you are shooting for. You may find, for example, that a Pils made with lots more chloride than the traditional water is to your preference because it sweetens the beer. You may not. You may find that ales with 50 ppm sulfate are preferable to those with 300. You will find both camps right here on HBT.

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Thanks for breaking it down for me, aj. Interesting to hear that replicating "historic" waters is maybe not really all it's cracked up to be.

Would it be succinct to paraphrase your summary by saying that there are just established parameters within which the chemistry is favorable to the mashing process/production of flavors during fermentation, and then attributes like hop crispness and mouthfeel should be tweaked to taste without trying to mimic an exact water profile?