High Mg in water/bittering hops

[Jaxmickey]

Hey Everyone,

I have 34.35 mg/L of Mg in my water. According to the calculator in brewer's friend, it's way too high and will bitter my beer (target is 10 mg/L). Can I subtract the amount of bittering hops I use to balance it back out? If so, how do I calculate the change to my recipe?

Thanks in advance!

 

[ajdelange]

Different kind of bitterness. It's hard to make a recommendation without knowing the details of your water's chemistry. I'd just do what you normally do and if the beer has the characteristic sour/bitter quality associated with magnesium try cutting it in half with RO water and trying again. Or brew the beer with all RO water and then add Mg to the extent of 35 mg/L in the glass to see if the beer becomes bitter. There are questions here as 35 mg/L is pretty insignificant compared to the amount of magnesium in malt. Perhaps it is a bound/un-bound question.

 

[Jaxmickey]

Ca- 58.45 mg/L
Mg- 34.35 mg/L
HCO3 -1- 128 mg/L
SO4 – 157.5 mg/L
NA -1- 17.9 mg/L
CL -1- 28 mg/L
Hardness = 301.5 mg/L
Bicarbonate alkalinity = 129 mg/L

 

[ajdelange]

As you have alkalinity of about 2 mEq/L dilution with RO 1:1 (at least) is a good idea as it will get the alkalinity down to close to 1 mEq/L which is a desirable maximum. You will need to neutralize that with colored malts, sauermalz or bottle acid but shouldn't need too much of any of those if your base malts aren't too alkaline. 2:1 will get the alkalinity down to 2/3 mEq/L and the Mg down to 11 mg/L at which level no one will argue that it is too high.. Sulfate will be down to 32 which is great for many beers but way low for some others and chloride will be less than 10 which is too low for most beers so supplementation with CaCl2 in most cases and CaSO4 in some will be necessary.

 

[55x11]

As you have alkalinity of about 2 mEq/L dilution with RO 1:1 (at least) is a good idea as it will get the alkalinity down to close to 1 mEq/L which is a desirable maximum. You will need to neutralize that with colored malts, sauermalz or bottle acid but shouldn't need too much of any of those if your base malts aren't too alkaline. 2:1 will get the alkalinity down to 2/3 mEq/L and the Mg down to 11 mg/L at which level no one will argue that it is too high.. Sulfate will be down to 32 which is great for many beers but way low for some others and chloride will be less than 10 which is too low for most beers so supplementation with CaCl2 in most cases and CaSO4 in some will be necessary.

ajdelange - I always thought alkalinity as target is very beer-dependent. For dark beers (stouts, porters, brown ales, scotch ales) the alkalinity of >100ppm (2 mEq/L) is desirable, to bring up residual alkalinity.

As to Magnesium, some people say you shouldn't go above 40 ppm to avoid harsh bitterness, others say values as high as 80 ppm is still ok (Palmer/Kaminski book for example mentions some research on this).

 

[ajdelange]

I think (or hope) that that theory has been pretty thoroughly debunked by now. A good target alkalinity for most beers is 0 hence the success of so many in brewing with RO water. This includes some dark beers. For example, the typical Irish stout actually requires some acid to hit what we normally think of as a desirable mash pH. Those determined to keep the old dogma alive will argue that stouts actually taste better at higher than normal pH and if you enjoy your stout more if it is mashed at higher pH then by all means do whatever it takes to get that higher pH.

As I mentioned in No. 2 it is hard to get excited about a few 10's of mg/L magnesium when the malt magnesium is a percent or so of the malt's total weight. But as I also mentioned in that post much of this magnesium may be bound and never make it into the mash. I don't have access to my library right now so I can't look up the magnesium content of finished beer. Then there is the matter of personal taste. This is why I suggested OP try various levels of Mg to see what is tolerable to him.

 

[55x11]

I think (or hope) that that theory has been pretty thoroughly debunked by now. A good target alkalinity for most beers is 0 hence the success of so many in brewing with RO water. This includes some dark beers. For example, the typical Irish stout actually requires some acid to hit what we normally think of as a desirable mash pH. Those determined to keep the old dogma alive will argue that stouts actually taste better at higher than normal pH and if you enjoy your stout more if it is mashed at higher pH then by all means do whatever it takes to get that higher pH.

As I mentioned in No. 2 it is hard to get excited about a few 10's of mg/L magnesium when the malt magnesium is a percent or so of the malt's total weight. But as I also mentioned in that post much of this magnesium may be bound and never make it into the mash. I don't have access to my library right now so I can't look up the magnesium content of finished beer. Then there is the matter of personal taste. This is why I suggested OP try various levels of Mg to see what is tolerable to him.

I would agree on Mg, when in 1.040 or so beer the base malt provides 80ppm or so, if I remember correctly, it's hard to worry about lack of Mg.

But I am still very confused about your argument for alkalinity goal of 0 for most (all?) beers. You (obviously!) know a great deal about water chemistry, so what am I missing?

For example, does it mean the whole talk about adjusting profiles for style, buffering and targeting residual alkalinity depending on style (mostly color) of the beer is not right? This is the approach of Martin's Bru'n Water, Beersmith and Water book by Palmer and Kaminsky - for darker style beers we need higher residual alkalinity of at least >50-100, often higher than 100 - sometimes 150 or so. And if we include decent concentration of Ca, say 50-100 range, this pushes total alkalinity into 100-150+ range for sure.

Are you saying that one can use similarly low alkaline water profile for say pilsner/helles style and a stout - and still get pH right?

A quote from Palmer book, where he looks at brewing a stout with 100ppm (2mEq/L) alkalinity water (66 RA), which he argues is too low for this style

"To brew a rich foreign extra stout, we need a fair amount of alkalinity in the water to balance the acidity of the caramel and roast malts. Otherwise, the mash pH might be too low (~4.9) and the beer will take on a one-dimensional roast character, acidic and coffee-like. This beer should be smooth and rich, sweet and beguiling...

To brew this beer right, we need to increase the total alkalinity and the residual alkalinity. In addition, it would be nice to raise both the calcium and magnesium levels to 50 and 30 respectively.."

John Palmer; Colin Kaminski (2013-04-15T07:00:00+00:00). Water: A Comprehensive Guide for Brewers (Kindle Locations 4224-4226). Brewers Publications. Kindle Edition.

After treating the water in his example, he ends up with water of 150 RA and 183 total alkalinity, which is about 3.6mEq/L - and he is talking how Ca is still too low (40 or so) and needs to be boosted.

 

[ajdelange]

Here's how it works. The components of a mash (the water, the malts, the chemicals, if any, that you add) all come to you at an intrinsic (natural) pH. For the water and most base malts and for chemicals like chalk, sodium bicarbonate and lye, the intrinsic pH is higher than the typical desired mash pH. It takes acid (protons) to get those components to mash pH. We call the quantity of protons required for each component the 'proton deficit' of that component. Acids, roast and caramel/crystal malt have intrinsic pH's less than typical mash pH. To get them to mash pH we have to absorb protons from them and we thus say that they have proton surfeits which it is usually most convenient to think of as a negative proton deficit. In a separate category from either is calcium which, by itself, has no surfeit or deficit but which when reacted with the phosphate in malt releases protons and thus acts like an additional source of acid.

To hit a particular mash pH we calculate the proton deficit of each of the components and add them up. If the sum is a positive number we have a deficit and must add acid (or dark malt or calcium) to neutralize that deficit such that the sum of all the deficits is 0 and if the sum is negative then we have a surfeit and must add a proton absorber to the extent of the surfeit such that the sum is 0.

Note that RA hasn't been mentioned as yet. It is actually the sum of the waters deficit to pH 4.4 (or whatever pH the water's alkalinity was measured at) and the calcium induced surfeit on the assumption that each 3.5 mEq of calcium will release 1 mEq of protons. The problems with this are that a mEq of protons requires more like 7 - 10 mEq of calcium and that the proton deficit for the water at mash pH is, while it depends on source water pH, more like 90% of the alkalinity. These are fairly minor problems. Probably the greater on is the confusion that is caused when RA, which was conceived for comparing water supplies, is extended to include some but not all components of the mash. The situation is much clearer if RA is not mentioned at all IOW we if we rely on the shopping list of mash item deficits.

Computing the proton deficit of the water is pretty straight forward (with a spreadsheet) and the answer turns out to be, for mash pH in the 5.4 - 5.5 region, about 90% of the alkalinity (expressed in mEq/L times the number of liters of mash water). So water with alkalinity of 2 mEq/L would require about 1.8 mEq/L acid to get the water by itself to pH 5.4 - 5.5. Acidifying he water to mash pH is a decent strategy because once you have done that the proton deficit is 0 - the same as distilled water's proton deficit (or really very close to that of distilled water) and you can focus entirely on the grain.

The grains are the grains and have the proton deficits they have irrespective of their colors. Color is a reasonably strong correlate of malt DI mash pH but not a good enough one that we would want to rely on it for mash pH control/prediction. One can get much better results by measuring the malts' acid base properties but who are you going to get to do that?

Looking at the stout you referenced, let's suppose that the water has alkalinity of 2 mEq/L and that you are going to use 50 L of it to mash 18 kg of malt made up of 78% Maris Otter, 11 % flaked barley and 11% roast barley. To pH 5.5 the proton deficit of the water is 87 mEq and of the Maris Otter 127 mEq. The flaked barley requires 10.8 mEq and he roast barley supplies 99. The sum is +116 meaning that we need 116
mEq of protons from somewhere if we are to hit pH 5.5. If we 0 out the alkalinity (use RO water) that knocks out all the demand but 29 mEq worth and we still need 29 mEq of acid to reach pH 5.5. Increasing the roast barley to 14% would be enough to cover that but with that much roast barley things might be getting a bit too roasty. Doubling the calcium would allow us to get by with 13% roast barley.

We can clearly play games all afternoon with malt varieties, crystals malts etc. What I have given is a nominal Irish Stout recipe. For a more robust formulation you might want to use more roast barley to the point where you had a proton surfeit at the desired mash pH. In such a case you would want to use a more basic base malt or add base in the form of sodium bicarbonate or sodium hydroxide but we have illustrated here that even a stout can be made with 0 alkalinity and have a proper mash pH. Most beers will require some acid even if made with RO water.

Note that RA is not mentioned in any of this example design nor need it be. When John was writing the book I tried to push him away from RA and towards this new way of thinking (which was ginned up for him to use in the book) but he remained firm in his belief that RA is the way to explain all this most easily.

 

[55x11]

Here's how it works. The components of a mash (the water, the malts, the chemicals, if any, that you add) all come to you at an intrinsic (natural) pH. For the water and most base malts and for chemicals like chalk, sodium bicarbonate and lye, the intrinsic pH is higher than the typical desired mash pH. It takes acid (protons) to get those components to mash pH. We call the quantity of protons required for each component the 'proton deficit' of that component. Acids, roast and caramel/crystal malt have intrinsic pH's less than typical mash pH. To get them to mash pH we have to absorb protons from them and we thus say that they have proton surfeits which it is usually most convenient to think of as a negative proton deficit. In a separate category from either is calcium which, by itself, has no surfeit or deficit but which when reacted with the phosphate in malt releases protons and thus acts like an additional source of acid.

To hit a particular mash pH we calculate the proton deficit of each of the components and add them up. If the sum is a positive number we have a deficit and must add acid (or dark malt or calcium) to neutralize that deficit such that the sum of all the deficits is 0 and if the sum is negative then we have a surfeit and must add a proton absorber to the extent of the surfeit such that the sum is 0.

Note that RA hasn't been mentioned as yet. It is actually the sum of the waters deficit to pH 4.4 (or whatever pH the water is measured at) and the calcium induced surfeit on the assumption that each 3.5 mEq of calcium will release 1 mEq of protons. The problems with this are that a mEq of protons requires more like 7 - 10 mEq of calcium and that the proton deficit for the water at mash pH is, while it depends on source water pH, more like 90% of the alkalinity. These are fairly minor problems. Probably the greater on is the confusion that is caused when RA, which was conceived for comparing water supplies, is extended to include some but not all components of the mash. The situation is much clearer if RA is not mentioned at all IOW we if we rely on the shopping list of mash item deficits.

Computing the proton deficit of the water is pretty straight forward (with a spreadsheet) and the answer turns out to be, for mash pH in the 5.4 - 5.5 region, about 90% of the alkalinity (expressed in mEq/L times the number of liters of mash water). So water with alkalinity of 2 mEq/L would require about 1.8 mEq/L acid to get the water by itself to pH 5.4 - 5.5. Acidifying he water to mash pH is a decent strategy because once you have done that the proton deficit is 0 - the same as distilled water's proton deficit (or really very close to that of distilled water) and you can focus entirely on the grain.

The grains are the grains and have the proton deficits they have irrespective of their colors. Color is a reasonably strong correlate of malt DI mash pH but not a good enough one that we would want to rely on it for mash pH control/prediction. One can get much better results by measuring the malts' acid base properties but who are you going to get to do that?

Looking at the stout you referenced, let's suppose that the water has alkalinity of 2 mEq/L and that you are going to use 50 L of it to mash 18 kg of malt made up of 78% Maris Otter, 11 % flaked barley and 11% roast barley. To pH 5.5 the proton deficit of the water is 87 mEq and of the Maris Otter 127 mEq. The flaked barley requires 10.8 mEq and he roast barley supplies 99. The sum is +116 meaning that we need 116
mEq of protons from somewhere if we are to hit pH 5.5. If we 0 out the alkalinity (use RO water) that knocks out all the demand but 29 mEq worth and we still need 29 mEq of acid to reach pH 5.5. Increasing the roast barley to 14% would be enough to cover that but with that much roast barley things might be getting a bit too roasty. Doubling the calcium would allow us to get by with 13% roast barley.

We can clearly play games all afternoon with malt varieties, crystals malts etc. What I have given is a nominal Irish Stout recipe. For a more robust formulation you might want to use more roast barley to the point where you had a proton surfeit at the desired mash pH. In such a case you would want to use a more basic base malt or add base in the form of sodium bicarbonate or sodium hydroxide but we have illustrated here that even a stout can be made with 0 alkalinity and have a proper mash pH. Most beers will require some acid even if made with RO water.

Note that RA is not mentioned in any of this example design nor need it be. When John was writing the book I tried to push him away from RA and towards this new way of thinking (which was ginned up for him to use in the book) but he remained firm in his belief that RA is the way to explain all this most easily.

AJ, thanks a lot for a fairly long and detailed explanation. I need to do the numbers and think about it some more but I think I understand what you are saying.

Let me try to summarize it to make sure I get this correctly:

1. The crucial issue is mash pH. If you can get to desired mash pH, of say 5.3 or 5.5 or whatever, it basically doesn't matter what water profile you use, what alkalinity or residual alkalinity etc. (with caveats that you need some Ca for mash/yeast and perhaps some combination of Na, Mg for taste optimization, or Cl vs. S for enhancing certain flavors - but those are secondary issues?)

2. If you can get to the desired pH with RO water and very minimal additions, and basically choosing something with zero or close to it alkalinity, you should choose that route, rather than following historic water profiles of (usually) very alkaline water and then compensating back by acidifying the mash etc.
Perhaps the recipe can be tweaked in a relatively subtle way to arrive at the appropriate pH without sacrificing the taste - many different ways to get to the same target point, and the path of the least salt additions is the best one (?)

3. One still needs Ca content at around 50ppm or higher, and maybe some balance of Chlorides to Sulfites depending on the style, or add Na or Mg or other flavor salts, and that can be accomplished without adding bicarbonates making super-alkaline water.

is that about right?

 

[ajdelange]

1. The crucial issue is mash pH. If you can get to desired mash pH, of say 5.3 or 5.5 or whatever, it basically doesn't matter what water profile you use, what alkalinity or residual alkalinity etc. (with caveats that you need some Ca for mash/yeast and perhaps some combination of Na, Mg for taste optimization, or Cl vs. S for enhancing certain flavors - but those are secondary issues?)

Yes, pH is most important but as there are several ways to get a proper pH with a given water one must be aware of the effects of the different methods. Adding acid will take care of any level of alkalinity but leaves the equivalent quantity of the anion of the acid used etc.

2. If you can get to the desired pH with RO water and very minimal additions, and basically choosing something with zero or close to it alkalinity, you should choose that route, rather than following historic water profiles of (usually) very alkaline water and then compensating back by acidifying the mash etc.

The important thing to keep in mind with respect to historical profiles is that in most cases the alkalinity is not stated and if it is it is wrong and finally most breweries, one way or another, decarbonated their water because they had to.

Perhaps the recipe can be tweaked in a relatively subtle way to arrive at the appropriate pH without sacrificing the taste - many different ways to get to the same target point, and the path of the least salt additions is the best one (?)

You should research the style as fully as you can. Clearly one can use RO water and sauermalz to establish correct mash pH for any beer but sauermalz just wouldn't be the way to do it for a Northern English ale. They use hydrochloric and sulfuric acids to deal with alkalinity (water and malt) leaving chloride and sulfate ion in the beer which ions are an important part of the style.

3. One still needs Ca content at around 50ppm or higher,

Lots of beers are made with less than 50 ppm Ca.

.. and maybe some balance of Chlorides to Sulfites depending on the style, or add Na or Mg or other flavor salts, and that can be accomplished without adding bicarbonates making super-alkaline water.is that about right?

Yes.

 

[55x11]

Lots of beers are made with less than 50 ppm Ca.

thanks, I am really grateful for your responses!

Just a quick question on Ca requirements:
My understanding is that most beers made with <50ppm (perhaps as low as 20ppm or so) are lagers (e.g. pilsners) - is that primarily because the yeast already flocculates so well and there is extended lagering process that the Ca is not that needed? In other words, are we often adding majority, say 30+ppm of Ca just for flocculation - nothing to do with mash or yeast health?

 

[Yooper]

thanks, I am really grateful for your responses!

Just a quick question on Ca requirements:
My understanding is that most beers made with <50ppm (perhaps as low as 20ppm or so) are lagers (e.g. pilsners) - is that primarily because the yeast already flocculates so well and there is extended lagering process that the Ca is not that needed? In other words, are we often adding majority, say 30+ppm of Ca just for flocculation - nothing to do with mash or yeast health?

Correct. 50+ ppm assists in flocculation, as well as helps prevent beerstone.

 

[GnenieGone]

Hey Everyone,

I have 34.35 mg/L of Mg in my water. According to the calculator in brewer's friend, it's way too high and will bitter my beer (target is 10 mg/L). Can I subtract the amount of bittering hops I use to balance it back out? If so, how do I calculate the change to my recipe?

Thanks in advance!

There is going to be a lot of opinions about this subject. Personally, I've systematically eliminated potential sources of off-flavors over time and eliminating Mg was one. I use only RO with no Epson Salt addition anymore (gypsum/CaCl and maybe pickling lime) "less is more". This was Yooper's recommendation so followed suit. There is plenty of Mg in the grains we use.

 

[ajdelange]

thanks, I am really grateful for your responses!

Just a quick question on Ca requirements:
My understanding is that most beers made with <50ppm (perhaps as low as 20ppm or so) are lagers (e.g. pilsners) - is that primarily because the yeast already flocculates so well and there is extended lagering process that the Ca is not that needed?

I think it's primarily because those beers were traditionally made with low calcium water and people like their low mineral flavor. The fact that they are cold lagered long enough to precipitate the yeast helps with this, of course.