Bru N Water profile for an APA using 100% distilled water - Sparge question

[rwing7486]

This weekend I plan to brew an APA (Grain bill below) using 100% distilled water for the first time. Reason being is I have an annual golf outing in early May with friends from high school and I plan to bring a keg of this brew to the event. With that said I have noticed that the last 2 batches I brewed with my tap water seemed astringent. I have not sent my water in for analysis since 2 years ago so I am guessing it has changed. Since I do not have time to send a water sample in for analysis I am going to buy 100% distilled water.

Batch Size: 5.5 gallons
Batch Sparge
Grain Bill
8lbs 12oz - Pale 2 row (2L)
12oz - American Rye (3.7L)
12oz - Munich (10L)
4oz - Crystal 80L
4oz - White wheat (2.5L)


Attached is a screen shot of my finished APA profile with the minerals I added. Using these additions I get an estimated mash room temp pH of 5.4. Now I know the nominal pH of distilled water is 7 and I intend to add my Gypsum and CaCl mineral additions to my sparge water prior to starting my batch sparge. So my question is there a way to determine how much my sparge water pH will be reduced by my mineral additions using the software? I only have paper strips and a pH meter that reads pH at room temp. I could use my pH meter if I mix in my minerals to the sparge water at room temp but I am not sure if they will fully dissolve at this temp which could lead to an inaccurate reading.

Lets say that I receive an accurate pH reading from the room temp mineral additions and it has a pH of 6.5. Using the "sparge acifidication" tab I am trying to calculate how much latic acid I would need to reduce the pH down to 6. Is it safe to assume there is "0" alkalinity in my distilled water or should i use 1ppm for my latic acid calculation?

Maybe an easier way to accurately calculate my latic acid addition would be to add my "sparge" minerals directly to the boil kettle prior to boil. This would allow me to sparge with pure distilled water which would let me assume the starting pH of my sparge will be 7 and i can add 0.04mL of latic acid to reduce it to my desired pH of 6? See attached "APA sparge" picture

Thanks in advance for everyone's feedback!

Rob

 

[Homercidal]

Which version of Bru'nwater are you using? My version has an option for inputting a percentage of the sparge water as RO/Distilled water.

Also note that there is a setting for Sparge Volume, which if set to 1 will use the volume from the sparge amount in the Adjustment Calculator worksheet.

 

[rwing7486]

Which version of Bru'nwater are you using? My version has an option for inputting a percentage of the sparge water as RO/Distilled water.

Also note that there is a setting for Sparge Volume, which if set to 1 will use the volume from the sparge amount in the Adjustment Calculator worksheet.

I didnt realize there was a new version. I just made a donation so hopefully Martin will send me the version you show above shortly When you say set to "1" is that on the new version? I am assuming you say that because if I enter "1" in the "water adjustments" tab it will multiply by the volume I have set from the "sparge calculator" sheet - correct?

 

[ajdelange]

The way the problem is solved is to
1)Pick a pH.
2)Determine how much acid it takes to get the water to that pH then treat the entire volume of water to get it to that pH.
3)Determine how much acid it takes to get the malts to the target pH and add that to the mash (or really the mash water).

WRT 1) you have picked 5.4
WRT 2) you have chosen an ion profile which requires the addition of acid to reach pH 8 at which the profiles are specified and more acid to reach mash pH because, as is the case with many of the profiles, you can't get the desired calcium or sodium without adding base and thus need the acid to neutralize them. I don't know how much you care about matching the target profile but the resulting additions will get you there exactly as you will see if you punch them in:

Salt/Acid/Base mg/gal Synth
CaCl2.2H2O 333.16
NaCl 60.34
MgCl2.6H2O 31.23
CaSO4.2H20 1578.88
MgSO4.7H20 653.05
H2O (DI) Liters 0.00
CaCO3 178.55
NaHCO3 259.05
CO2 0.00
HCl 0.00
Ca(OH)2 0.00
Na2CO3.H2O 0.00
Sodium Lactate 0.00
Potassium Lactate 0.00
Lactic 577.16
Sulfuric 0.00
88% Lactic ml/Gal 0.54

The lactic acid is required to neutralize the bases you chose to add to the water in order to hit the profile at the mash pH. The water's alkalinity is now 0 and does not need to be considered further. No treatment is required for the sparge water other than what you have already done to it.

3). The alkalinity requirement of the grist is a rather modest (I chose Rahr Pale ale malt) 2.5 mEq/L of mash water. You can get that by increasing the lactic acid in the mash water only to 1.24 mL/Gal

Some might argue that this is too much lactic from the flavor point of view. The first thing I would do is eliminate the acid required to treat the water by removing the bicarbonate, carbonate and lime from the synthesis. That gets rid of 0.54 mL/gal.

 

[rwing7486]

The way the problem is solved is to
1)Pick a pH.
2)Determine how much acid it takes to get the water to that pH then treat the entire volume of water to get it to that pH.
3)Determine how much acid it takes to get the malts to the target pH and add that to the mash (or really the mash water).

WRT 1) you have picked 5.4
WRT 2) you have chosen an ion profile which requires the addition of acid to reach pH 8 at which the profiles are specified and more acid to reach mash pH because, as is the case with many of the profiles, you can't get the desired calcium or sodium without adding base and thus need the acid to neutralize them. I don't know how much you care about matching the target profile but the resulting additions will get you there exactly as you will see if you punch them in:

Salt/Acid/Base mg/gal Synth
CaCl2.2H2O 209.84
NaCl 176.32
MgCl2.6H2O 0.08
CaSO4.2H20 1633.61
MgSO4.7H20 575.66
H2O (DI) Liters 0.00
CaCO3 190.52
NaHCO3 92.33
CO2 0.00
HCl 0.00
Ca(OH)2 29.64
Na2CO3.H2O 0.00
Sodium Lactate 0.00
Potassium Lactate 0.00
Lactic 505.90
Sulfuric 0.00
88% Lactic ml/Gal 0.48

The lactic acid is required to neutralize the bases you chose to add to the water in order to hit the profile at the mash pH. The water's alkalinity is now 0 and does not need to be considered further. No treatment is required for the sparge water other than what you have already done to it.

3). The alkalinity requirement of the grist is a rather modest (I chose Rahr Pale ale malt) 2.5 mEq/L of mash water. You can get that by increasing the lactic acid in the mash water only to 1.26 mL/Gal

Some might argue that this is too much lactic from the flavor point of view. The first thing I would do is eliminate the acid required to treat the water by removing the bicarbonate, carbonate and lime from the synthesis. That gets rid of 0.48 mL/gal.

I guess I am confused. So correct me if im wrong but your are saying is for calculation purposes is to treat the total water volume (Mash+sparge = 10 gallons) to a desired pH - in my case 5.4. so From there I add my 4 gallons for my mash and let the mash sit for desired sac rest. The remaining volume of water will be my sparge, BUT because I have added baking soda and pickling lime I will need to reduce the pH, Alkalinity and excessive bicarbonate by adding lactic acid?

 

[ajdelange]

I guess I am confused. So correct me if im wrong but your are saying is for calculation purposes is to treat the total water volume (Mash+sparge = 10 gallons) to a desired pH - in my case 5.4.

Sorry about the confusion. This has recently become more clear to me as the obvious way to solve these problems and I want to expose people to it.

Yes, you treat the entire water volume (10 gals) by adding those salts and the lactic acid indicated in #4.

... so From there I add my 4 gallons for my mash and let the mash sit for desired sac rest.

When you treated all the water you took care of its acid requirement which arose from the fact that you would have to add calcium carbonate, calcium hydroxide and sodium bicarbonate to it to match the profile's calcium and sodium requirements.

Now you must see to the grist's acid reqirement. It is an additional 1.26 - 0.48 = 0.78 ml/gal of the mash water only.

The remaining volume of water will be my sparge,

Yes.

BUT because I have added baking soda and pickling lime I will need to reduce the pH and Alkalinity by adding lactic acid?

No! You already did that when you treated the entire water volume to pH 5.4 in step 1.

 

[rwing7486]

Sorry about the confusion. This has recently become more clear to me as the obvious way to solve these problems and I want to expose people to it.

Yes, you treat the entire water volume (10 gals) by adding those salts and the lactic acid indicated in #4.


When you treated all the water you took care of its acid requirement which arose from the fact that you would have to add calcium carbonate, calcium hydroxide and sodium bicarbonate to it to match the profile's calcium and sodium requirements.

Now you must see to the grist's acid reqirement. It is an additional 1.26 - 0.48 = 0.78 ml/gal of the mash water only.


Yes.

No! You already did that when you treated the entire water volume to pH 5.4 in step 1.

I guess I am still confused then becuase I do not understand how I achieve an acceptable mash pH. If I eliminate the bases (baking soda and pickling lime) and add gypsum, NaCl and lactic acid then my mash pH will be below 5. If i eliminate the lactic acid my estimated room temp mash pH is 5.2 with 0 alkalinity and RA of -110

 

[ajdelange]

If you supply the proper quantity of acid to the water to bring it to the desired mash pH and the proper quantity of acid to the grains to bring them to the desired mash pH then everything is at the desired mash pH. I can tell you how to do that based on the fundamental chemistry (which I have done) but I cannot tell you how to do that with Bru'n water. Perhaps someone with more familiarity with the program can do that.

 

[bigdaddybrew]

The Brun'water spreadsheet works well for me. I get good results using it to estimate mash ph but I don't have a ph meter. I like to be on the lower end for my lighter colored beers 5.2 to 5.3 it seems to make them brighter. In my darker beer 5.4 to 5.5 seems to make them smoother. I use R/O water. I add 1/2 tsp Gypsum 1/2 tsp Calcium Chloride and a 1/4 tsp of sea salt for 5 gallons of mash water. I get this basic profile...
Ca 49
Mg 0
SO4 59
Na 31
Cl 91
HCO3 0
ALK 0
Then I enter my grain bill and mash thickness into the spreadsheet and make adjustments using Phosphoric acid or Pickling lime to get a predicted mash ph. To accenuate the bitterness you could start with more Gypsum. I use the same mineral additions for the sparge water but do not add any Pickling lime. You can measure the ph of the sparge water and add acid if you want to match the mash ph but I batch sparge and this profile has no buffering capacity so I don't bother.

 

[ajdelange]

The Brun'water spreadsheet works well for me. I get good results using it to estimate mash ph but I don't have a ph meter.

Forgive me for asking the obvious question but if you don't have a pH meter how do you know it works well for you in estimating mash pH?

 

[beskone]

I guess I am still confused then becuase I do not understand how I achieve an acceptable mash pH. If I eliminate the bases (baking soda and pickling lime) and add gypsum, NaCl and lactic acid then my mash pH will be below 5. If i eliminate the lactic acid my estimated room temp mash pH is 5.2 with 0 alkalinity and RA of -110

Are you are adding salts to the full volume of your water (mash and sparge)?

Are you then entering that profile into the water report section of Bru'n Water?

If not the Sparge acidification page is useless.

 

[Gnomebrewer]

Your process will be a whole lot simpler if you don't add any alkalinity (bicarb soda, chalk or pickling lime) to your water. You don't need to match the bicarbonate given in the 'pale ale' profile - it's all the other flavouring minerals that you're interested in. You can get close to the numbers without adding bicarb or lime or chalk (you'll be slightly low on Ca and/or Mg).

Without alkalinity in your water to worry about, you will need little to no acid in the mash (I haven't run the numbers to see exactly how much) and you won't need any acid for the sparge - add the salts to the kettle rather than to the sparge water, so you sparge with straight distilled water. You don't need to worry about the pH of the sparge water because it has no buffering capacity (it's distilled).

Summary: Use CaCl2, Mg/CaSO4 and NaCl to get as close to your target profile as you can. Add the calculated mash salts to the mash with an acid addition if required. Sparge with pure distilled water. Add the salts calculated for your sparge water directly to the boil kettle.

 

[Gnomebrewer]

I think a fundamental question needs to be asked. Are you sure you want the amount of mineralisation shown in the pale ale profile? I don't. Most beer drinkers (IME....based on family/friends drinking my beer) don't.

I guess I am still confused then becuase I do not understand how I achieve an acceptable mash pH. If I eliminate the bases (baking soda and pickling lime) and add gypsum, NaCl and lactic acid then my mash pH will be below 5. If i eliminate the lactic acid my estimated room temp mash pH is 5.2 with 0 alkalinity and RA of -110

If you eliminate the bases, you only keep the acid if it's needed for pH adjustment. If you eliminate the bases and the acid and mash pH is still low (5.2), you need a small amount of alkalinity to bring it up a bit. You only need it in the mash though - not the sparge/kettle. HOWEVER, if you decide (as I asked above) that you don't need all those other mineral in your beer, you'll also find the pH is higher without adding alkalinity (because there are less salts bringing the pH down).

 

[bigdaddybrew]

Forgive me for asking the obvious question but if you don't have a pH meter how do you know it works well for you in estimating mash pH?

Well that is why qualify my advice by stating up front that I don't have a ph meter. I can't comment on how close my actual mash ph is to the estimate from Brun'water.

I started using plain RO water because my well water is terrible. I made some good extract beers however the resulting all grain beers had a watery finish. My pale beers were bland. My all grain ambers were better but had a thin mouth feel. My browns were a bit harsh. So I started building my brewing water from RO and trusting the Brun'water spreadsheet to estimate the mash ph. Now my pales are bright, my ambers are delicious and my browns are smooth and tasty.

I keep seeing many homebrewers who want to advance their beer quality by adjusting their water but struggle to understand the chemistry and may not want to invest in a ph meter. This method serves me well and I hope it's simplicity will help other brewers improve their beers. By the way a ph meter is on the list but until then this "works well for me".

 

[ajdelange]

Your process will be a whole lot simpler if you don't add any alkalinity (bicarb soda, chalk or pickling lime) to your water.

From #4:

3). The alkalinity requirement of the grist is a rather modest (I chose Rahr Pale ale malt) 2.5 mEq/L of mash water. You can get that by increasing the lactic acid in the mash water only to 1.24 mL/Gal

Some might argue that this is too much lactic from the flavor point of view. The first thing I would do is eliminate the acid required to treat the water by removing the bicarbonate, carbonate and lime from the synthesis....

Without alkalinity in your water to worry about, you will need little to no acid in the mash (I haven't run the numbers to see exactly how much)

From # 4

...That gets rid of 0.54 mL/gal.

So if he does the exact synthesis (given in #4) he would need a total of 1.24 mL 88% lactic per US gal in the mash water with 0.54 to handle the allkalinity (WRT mash pH) introduced by the synthesis and 1.24 - 0.54 = 0.70 for the alkalinity of the grist. The sparge water needs only the 0.54.

....and you won't need any acid for the sparge - add the salts to the kettle rather than to the sparge water, so you sparge with straight distilled water. You don't need to worry about the pH of the sparge water because it has no buffering capacity (it's distilled).

It doesn't matter either way. In an exact synthesis acid has been added to neutralize the bases. The alkalinity of the water WRT mash pH is 0. If the bases are just left out the salts can still be added to the sparge water and its alkalinity is still 0 WRT mash pH (with the exception of small alkalinity of water itself and the teeny, tiny alkalinity of the sulfate ion).

Use CaCl2, Mg/CaSO4 and NaCl to get as close to your target profile as you can.

I don't understand why Bru'n contains profiles that cannot be put together with just those salts (from DI water). Asking for the closest synthesis to this profile with those plus MgCl2 gives a result which is pretty close to what is in the current profile:

Salt Target Realized
Calcium 140 121.6295
Magnesium 18 17.4996
Sulfate 300 335.2029
Chloride 55.00 56.6029
Sodium 25.0000 24.4896

Why not make these revised numbers the profile? Does it really matter in terms of the intent that calcium is at 121 instead of 140 or that the sulfate is 12% high? Sulfate of 300 is obscene but 335 is only half a dB more so.

 

[rwing7486]

Thanks for the feedback everyone. Below is an updated profile in which I eliminatedo the base mineral additions. I still yield an estimated mash pH of 5.4 with these gypsum and CaCl additions. With that said my only worry i have is having too high of a pH when using distilled water. Since distilled water has a pH of 7 should I still add lactic acid to get it down to 6 for i don't risk extracting tannins during my sparge?

 

[McKnuckle]

If you are sparging with water to which you have added CaCl and gypsum, your pH will be fine. Treat the 10 gallons at once, so that the entire volume of water has the same mineral concentrations. Then split it for mash and sparge as needed.

 

[ajdelange]

Distilled water usually has a pH in the 5's or 6's but in any case its alkalinity is about 2 ppm as CaCO3 and as such not something you need to worry about.

 

[rwing7486]

So i should be OK with either sparging with just pure distilled and adding sparge mineral additions directly to the brew kettle or I can mix all 10 gallons with total mineral additions and just split the volume for the mash and sparge?

 

[ajdelange]

As long as the mineral additions have 0 proton deficit WRT target pH which means no carbonates, bicarbonates, hydroxides, phosphates or acids of any kind, yes.

 

[mabrungard]

The initial targeted Pale Ale profile would require an addition of an alkali to the mashing water since the amount of calcium and magnesium salts added to the mashing water is high and that produces excess protons via the reaction with phytin. I see that the subsequent selected water profile has a more moderate amount of those salts and it would not need the alkali. Either option is fine, it depends on what your flavor goals are.

Since you are starting with distilled water that has virtually no alkalinity, there is no need to acidify the sparging water. There are notes to that effect in the Bru'n Water program. However if you were using an alkaline water source, neutralizing the alkalinity to near zero (I feel that less than 25 ppm alkalinity is sufficient) is a necessary thing for avoiding problems during sparging.

Neutralizing high alkalinity with an acid addition is important for sparging water. Adding calcium and magnesium salts to sparging water DOES NOT produce the same acidifying effect as it does in the mash. The supply of phytins will have been largely been flushed from the grain mass and that reaction won't occur to a large degree. So don't assume that mineralizing the sparging water is an alternative to proper acidification. With that said, it is OK to add your calculated mineral dose for the sparging water to either the sparging water or to the kettle.

 

[ajdelange]

The initial targeted Pale Ale profile would require an addition of an alkali to the mashing water since the amount of calcium and magnesium salts added to the mashing water is high and that produces excess protons via the reaction with phytin.

You force him to add alkali in order to get the specified calcium level which requires him to use acid to offset the alkali in order to reach mash pH and now you want him to add alkali to offset the calcium he realized by adding alkali in the first place? Head is spinning here.

A sensible approach would be to compute the acid required to neutralize the alkaline calcium compounds used to reach mash pH and the amount of acid required to neutralize the grain and and then deduct from their sum the amount required to absorb the Kohlbach shift which, in any case will be quite small. Don't forget that the Kohlbach shift was as observed at knockout. Of the [Ca++]/3.5 mEq protons estimated at knockout obviously less than that are available to influence mash pH.

 

[mabrungard]

You force him to add alkali in order to get the specified calcium level which requires him to use acid to offset the alkali in order to reach mash pH and now you want him to add alkali to offset the calcium he realized by adding alkali in the first place? Head is spinning here.

AJ, you are being dense here. The calcium level is not the specification. It is the high sulfate level that is driving the high calcium level. That resulting calcium level drives the Kohlbach pH shift. The alkali addition is therefore an unavoidable requirement when you start with very low or no alkalinity water and want to have that high sulfate level in your beer.

Reach up and hold your head! I realize that having this high level of sulfate in beer is anathema for you, but some beer drinkers enjoy it.

 

[ajdelange]

AJ, you are being dense here.

Well I certainly feel dense many times in a given day but this isn't one of them.

The calcium level is not the specification. It is the high sulfate level that is driving the high calcium level.

Looking at the profile I don't know how I (or anyone else) is to know that the 140 mg/L number isn't part of the spec but the 300 mg/L number is. If high calcium is a problem set the spec for 104.7 mg/L. That's sufficient to realize 300 ppm sulfate and meet all the other numbers in that profile except bicarbonate (which doesn't count). If you don't believe 300 mg/L can be acheived with 104.7 mg/L Ca++ put these numbers into your spreadsheet:

Salt/Acid/Base mg/gal Synth
CaCl2.2H2O 129.07
NaCl 240.56
MgCl2.6H2O 0.00
CaSO4.2H20 1552.38
MgSO4.7H20 690.91
H2O (DI) Liters 0.00
CaCO3 0.00
NaHCO3 0.00
CO2 0.00
HCl 0.00
Ca(OH)2 0.00
Na2CO3.H2O 0.00
Sodium Lactate 0.00
Potassium Lactate 0.00
Lactic 3.55
Sulfuric 0.00
88% Lactic ml/Gal 0.0033

Note no bases or acids needed (other than the tiny amount of Lactate required to overcome the alkalinity of the sulfate and the water itself) which, as I have shown in several posts in this thread, would be required to get to a calcium level of 140.

That resulting calcium level drives the Kohlbach pH shift. The alkali addition is therefore an unavoidable requirement when you start with very low or no alkalinity water and want to have that high sulfate level in your beer.

As I noted in my last post the shift is going to be small. Assuming a reasonably typical ale grist with 1.5 quarts per pound mashing ratio the malts are going to require approximately 7.9 mEq acid per liter of strike water and assuming the Kohlbach protons are 100% of what his findings indicated at knockout those protons would supply 1.7 mEq of that acid, enough to shift a typical grist 0.02 - 0.04 pH. But assuming we want to wipe that shift out entirely we add 6.2 mEq (or a bit more as I wouldn't expect to get the full 1.7 in the mash) to each liter of the strike water and Bob's your uncle. No alkali needed.

Reach up and hold your head!

Yes, barring some glaring mistake I think I can hold my head up here.

I realize that having this high level of sulfate in beer is anathema for you, but some beer drinkers enjoy it.

That's hardly the point. In #15 I densely assumed that the stated calcium requirement was as much a requirement as the sulfate and only forbidding the use of alkali in the synthesis (and thus the requirement for acid) found the sulfate to go up to 335 observing that though 300 would be anathema 335 would only be anathema + 0.5 dB and not noticeable.

 

[cyanmonkey]

Can't we all just get along?!?!

 

[ajdelange]

If it means refraining from discussion of things that are inconsistent, don't make sense or just don't seem right then the answer is "no".

If I'm in error I want to know about it. The only thing that is out of bounds as far as I am concerned is how big my hands are.

If Martin wants to call me dense my reaction is to think that perhaps I am being dense about the particular issue and go check on it. If it turns out I am on solid ground I then explain why I think so. At the end of the day both Martin and A.J. should be wiser than they were at the beginning. If Martin comes back with an explanation as to why I am wrong then we're still both wiser.

 

[Homercidal]

So if I understand Martin correctly, the excess calcium was added strictly in order to get the ppm of Sulfate way up where the brewer wants it. Therefore the calcium drives the pH down and due to the existing water profile some alkali is needed to bring the pH back into range while keeping the added sulfate.

 

[ajdelange]

So if I understand Martin correctly, the excess calcium was added strictly in order to get the ppm of Sulfate way up where the brewer wants it.

Yes, but he added more than he had to to get that sulfate level. To get to that unnecessary higher level without exceeding the specified sulfate level he has to add calcium lactate or calcium phosphate or calcium somethingorotherate. As he doesn't have those salts he must use calcium carbonate or calcium hydroxide and this, of course, raised the pH so he must neutralize with lactic, phosphoric or somethingorotheric acid. Were Martin to have specified 104.7 mg/L Ca instead of 140 no extra acid for the water profile synthesis would be required but the brewer still has to use acid to cancel the alkalinity of the grain bill in a typical pale ale grist (unless he uses sauermalz for that job).

Therefore the calcium drives the pH down and due to the existing water profile some alkali is needed to bring the pH back into range while keeping the added sulfate.

The calcium does react with malt phytin to produce some acid and neutralize some of the malt alkalinity. But as it is not nearly enough to fully do that (at reasonable mash pH) there is still a proton deficit and that must be supplied by the brewer in the form of added acid. The simplest thing to do is not worry about this as the shift from ignoring it is probably going to be at most 0.03 pH but of one does wish to worry about it then he simply deducts the acid produced by the calcium reaction from the acid that he must add for the grist (or deducts it from the sauemalz if he uses that).

This all seems terribly simple to me but no one (except maybe the Taswegian bloke) seems to understand. Is this a difficult concept to grasp? If it is please say so and I'll keep trying to explain. Understanding this turns estimating mash pH from a fairly complicated job into a rather simple one. Understanding what is going on in your mash tun can only make you a better brewer.

 

[Homercidal]

Well, the chemical process is a bit over my head. Couldn't we just fire a few Phytin Torpeodes in there to make it all work? (Ok, stupid Star Trek joke...)

I tend to think in more basic terms of this plus that equals this. I AM interested in knowing more about the chemical process, but I have no foundation to start from. I'm nearly at ground zero on chemistry.

 

[Homercidal]

I just re-read your post and I think it's clicking. I will have to go back over the whole thread and read through the calculations again to really get it. I have to pick up the kid from school and will try to get back to this in a bit.

I generally don't have to worry about exceeding the calcium or sulfate levels since my water is so alkaline. I usually brew with RO, so if I go over I can just mix 50/50 and adjust from there.

 

[copper2hopper]

Why is it that I ALWAYS end up with a negative RA when formulating a water profile. I primarily do IPA and APA recipes and always have to pump in lactic acid to knock my ph to within range. How much is too much lactic acid and is a negative RA something to be concerned about? Also with my ending water profile my cations and anions are far apart from one another. I thought they are wanted to be as close to equal to eachother as possible. And yes I know I'm plugging stuff in correctly. I also always build up from distilled water.

 

[ajdelange]

Why is it that I ALWAYS end up with a negative RA when formulating a water profile. I primarily do IPA and APA recipes and always have to pump in lactic acid to knock my ph to within range. How much is too much lactic acid and is a negative RA something to be concerned about?

The concept of RA was first advanced by Paul Kohlbach in 1941. The original paper was lost as a consequence of the war and so he revisited the subject in another paper in 1953. Discussion of it was found in textbooks thereafter but it didn't really go public until a talk I gave in 2002 at the Craft Brewer's Conference in which I presented that chart that you'll find in Bru'n water and elsewhere. John Palmer, ever looking for a way to make the brewer's life easier jumped on it and really wanted to make it the basis of his Water book which he more or less did. The interesting thing about RA is that it cannot be the basis for water treatment but it is a very important part of it.

The basis for brewing water treatment is that the sum of the proton deficits (the amount of acid you must add to a given mash component to get it to a desired mash pH) must be 0. This means that some of them must be less than 0 and added acids or acidic malts (sauermalz, dark malts) do indeed have negative proton deficits with respect to desirable mash pH's. So using the letter D to represent a proton deficit we need

Dm1 + Dm2 + Dm3.... + Da + Db + Dw + Dphos = 0

m1 means malt1 etc
a means an acid you add (Da < 0)
b means a base you add
w means the water. Dw is about 90% of the reported alkalinity of the water at pH 5.4
phos designates the reaction between malt phosphate and calcium ions. Dphos < 0

Dphos = -([Ca++] + [Mg++]/2)/3.5

in which the values in brackets are the concentrations of the two ions in mEq/L. Dphos added to the alkalinity of the water gives the residual alkalinity

RA = Dw + Dphos = Dw -([Ca++] + [Mg++]/2)/3.5

so our balance condition now becomes

Dm1 + Dm2 + Dm3.... + Da + Db + RA = 0

It's easy to see how we design a beer from this. Compute Dm1, Dm2 etc, add on the RA and if the sum is > 0 add acids (with their negative Da's) or more or a new dark malt (with their positive Da's until the sum is 0. If the sum is negative then we add a base (Db > 0) or more malt with Dm > 0 or remove malt with Dm < 9. With a properly designed spreadsheet you can whip out recipes really quickly while gaining great insight as to what the roles of the individual components are.

The problem you are seeing isn't really a problem. The RA the popular spreadsheets and calculators display is actually (as far as I can tell) Da + Db + Dw + Dphos , IOW Kohlbach's RA plus the proton deficits of the added acids and bases. That sort of makes sense as it is the RA of the treated water if you add all the acids and bases to the water or the treated water as added to the mash if you add acids or bases to the mash tun.

As most beers require that you add some acid with it's negative proton deficit it should be clear that the sum of the water's actual RA and the acid's negative deficit is going to be smaller than the actual RA and, if acid in quantity greater than the RA is used, the sum can easily be negative. That's what you are seeing. Given that the RA as presented is not useful information without the malt components just ignore it.

I think most users of these programs are smart enough to know that in synthesizing a mineral profile they should not try to chase the bicarbonate. What many may not know is that lots of the profiles use calcium carbonate and lime as sources of calcium and sodium bicarbonate as a source of sodium. If that is done acid will have to be added to neutralize the alkalinity of those salts to mash pH at which pH 90% of the alkalinity attributable to them has been removed. This leaves calcium and magnesium at elevated levels with no compensating alkalinity (that was the intention) and, consequently, a more negative RA. It also requires more acid to the point that you may wind up with more than you want. My advice is to not use any of the alkaline salts. The neutral one's will usually get you reasonably close to the targets.

Also with my ending water profile my cations and anions are far apart from one another. I thought they are wanted to be as close to equal to eachother as possible.

I pointed this out and was told that you have to have the paid version for the cation and anion fields to be correct. But don't worry. As water is balanced and any salt you can buy is balanced mixing them together results is a balanced combination.

 

[copper2hopper]

Great! So keeping it simple, cuz I went a little cross eyed reading that, and also after reading palmers water book,....don't worry about negative RA and cations and anions being far apart.

Then how much lactic acid is too much? My last batch only required 4ml. My next one (from a different water source I want to try) will require 8ml. My usual starting volume is 8 gallons of water.

 

[ajdelange]

Then how much lactic acid is too much?

That's a tough one to answer because it is really a matter of your personal taste. If you like the flavor of lactic acid you might well accept more of it than people that don't like it. But then a Pils that tastes like a Gueze isn't really a pils.

I think most people would agree that a 3% sauermalz content in a grist is well below the level of objectionability and certainly most of the German beers you drink are going to have been acidulated to about that level because that's how much it takes to get a Pilsner malt to a mash pH of 5.4 or so given that you have dealt with any alkalinity in the water. That amount of sauermalz corresponds to about 4 mL of lactic acid in a typical batch.

My last batch only required 4ml.

Should not have been a problem.

On Weyermanns web site someone asks about using sauermalz to make Berliner Weiße. The response inludes:

"To reach the “sourish” character 8% of Acidulated malt are a perfect rate." From which I think we can take it that 8% is going to be too much unless you want "sourish" character and that we ought to be pretty cautious at above, say, 6% (double the amount discussed above). Six percent sauermalz corresponds to about 8 mL of lactic acid in a 5 gal batch.

My next one (from a different water source I want to try) will require 8ml. My usual starting volume is 8 gallons of water.

That puts you right on the edge of the "be careful" zone. Lots of posters here look at someone's water and say "neutralize the alkalinity with acid" leaving out the caveat that every mEq of alkalinity that is removed in this way is replaced by a mEq of the anion of the acid used. I always suggest that people remove alkalinity by other means (dilution with RO water is the simplest conceptually) to the point that the acid required to remove alkalinity from the water is less than the amount required for the grains.

Probably the best thing for you to do is to add some lactic acid to a finished beer and figure out how much you can tolerate before you notice it or it becomes objectionable.

 

[copper2hopper]

Thank you AJ. I brewed last night and sacrificed my PH a little and cut back the called for 8ml of acid to 5 ml. It got my PH to 5.6-5.7 when measured at 90 degrees according to my Milwaukee ph56 meter. So we will see how it turns out.