Citric acid or phosphoric acid?

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pjj2ba

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I have high carbonate water and have been treating my water with lime to precipitate out a bunch of it. I let it sit overnight and then transfer it to my mash tun and HLT. Then I use phosphoric acid to bring the pH down to ~ 6. I'm getting low on the phosphoric acid and am getting ready to buy some more and was wondering about using citric acid instead. I haven't compared prices, but assume it is cheaper (but less stable - compared to phosphoric acid).

I did a little looking through the litereature and it looks like yeast (well at least Candida) have a mechanism to take up citric acid, so I assume it would be metabolized by the yeast and therefore flavor neutral (well, at least it won't taste like citric acid).

Does anyone have any thoughts on why I might use one or the other?

Here is my typical procedure. Most of my beers are on the pale side so I figure there is enough buffering capacity in the grain to handle my now de-carbonated water at ~ pH 6. When I do brew something dark I leave the pH a little higher. I realize people always say it isn't the pH of the water, that is important, it is the pH of the mash that matters. I personally think that it is the buffering capacity that matters - as in as long as it is low there is a good chance you pH will be in the proper range. I don't like to go through the hassle of chilling hot mash and using my pH meter to check the pH of the actual mash. I do have some reasonably accurate pH test strips I use to make sure I'm in the right ball park.

I always contemplate titrating with the lime and watching for a pH jump to tell me when to stop. However, I usually remember late at night that I need to set my water so I just toss in the amount the experience has shown me works well (~ 1 tsp). I assume, that this would simply allow me to use less acid to get the pH back down
 

ajdelange

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I've noted here before that in the earliest days of homebrewing nearly all the recipes one saw contained some citric acid. I expect that it would be pretty strong flavor wise and I don't see how yeast would metabolize it (obvious guess in the citric acid (Krebs) cycle but that isn't operating during fermentation).

Yes, it is the buffering capacity of the water i.e. its alkalinity that determines its effect on mash pH. Assuming that you have some permanent hardness (i.e. that there is more hardness than alkalinity) you should be able to decarbonate down to alkalinity of about 1 meq/L i.e. 50 ppm as CaCO3. It shouldn't take much acid to get you down to reasonable mash pH from that level especially if you make up the calcium that got precipitated during the lime treatment. I really don't think the requisite amount of citiric acid is going to give you something that tastes citrusy but as always an experiment (i.e. determine how much citric is really required via test mash and then taste an equal volume of water with that much citric acid in it.

Another possibility is lactic which is pretty flavor neutral (until you get a whole lot of it) and is very convenient to work with in the form of sauermalz. One percent of grist lowers mash pH about 0.1 pH.
 

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From what I've seen, Phosphoric acid is used by many brewers because of it's safety (I used Hydrochloric Acid now, but will be switching soon) and because of it's neutral flavor. I think the 2 most widely-used products are saurmaltz and phosphoric acid for lowering the pH.
 
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pjj2ba

pjj2ba

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I've noted here before that in the earliest days of homebrewing nearly all the recipes one saw contained some citric acid. I expect that it would be pretty strong flavor wise and I don't see how yeast would metabolize it (obvious guess in the citric acid (Krebs) cycle but that isn't operating during fermentation).
That's why I asked!

It takes me about 8 ml of phosphoric acid (10 %) to get the pH down to where I want it.

I would suspect that the yeast would take any citric acid up pretty quickly.

Ok, I did a little more looking and while uptake would be quick, it is repressed by glucose, so it would probably wait until that was used up. I thought maybe the yeast could use citrate for something else other than in the TCA cycle but it doesn't look like there is much other than possibly being converted to oxaloacetate and then PEP. Although it could be used for amino acid synthesis and I assume at least some level of that is going on during fermentation

If anyone want's to see some nice metabolic pathway diagrams (very up to date) like this one, check out this link KEGG Pathway Maps What is shown is the reference pathway, but you can use the drop down menu to select saccharomyces if you want.
 

Komodo

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I'm only now getting into water chemistry, and realize I'm digging up a thread here.

Did you end up using citric acid, and did you find the amount used to be similar/same as phosphoric? Was there any residual taste?

Also, is the granulated form of this at brewshops at 100%? If so, how do you mix up your required amount? Sorry if this sounds like ridiculous questions, but considering their strong power and effect, I want to make sure this is right.
 

mabrungard

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The 'amounts' of those acids are going to be quite different due to the strengths and the fact that the phosphoric acid is in liquid form. Unless the citric acid is adulterated, it should be 100%. You don't have to mix up the citric into a solution, but you do need a fairly accurate scale that measures into the tenths of a gram to help avoid an overdose. Citric can be added directly to the brewing water. Bru'n Water software has an acid calculator to assist brewers in figuring out how much of an acid they might need.
 

ajdelange

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Citric acid is made by fermenting glucose (with mold) and then filtering out the organic gunk and precipitating the citrate as the calcium salt. This is washed and then redissolved with sulfiuric acid. The citric acid then is separated from the calcium and sulfate ions using, I believe, some sort of membrane separation which should yield pretty pure stuff so I don't see purity as an issue. If you look for the stuff at health food stores it is usually labeled 100%.

Weighing anything out as a powder is complicated by uptake of moisture from the air. For precised work substances are heated in an oven and then transferred to a dessicator for cooling.

Another problem with citrate is that it is triuprotic i.e. it has up to 3 moles of protons to yield up per mole of the acid but the number actually given up depends on the pH at which one starts and at which one ends up. For example in acidifying water to pH 5.5 1.97 moles of protons are released for each mole of the acid. In acidifying to 5.9 it is 2.21 moles of protons per mole of acid. The number of moles of protons required of course depends on the alkalinity. So one has to take this into account when calculating amounts to be used.

Given all this it is probably best to just assume 2 moles of protons per mole of acid and then add the calculated amount incrementally while monitoring pH. This incorporates not only any errors from calculation but also from moisture and from any other source.
 

Komodo

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Gentlemen, thanks for the reply.
First off, I'm not sure I even NEED to acidify my water but but is fairly high Ph at 9. I'd like to clarify a couple small things. I've used Bru'n which led me to this post.

On the 2nd Bru'n spreadsheet '2. Sparge Acidification' you see citric acid under acid type. What I have is the powdered citric acid from the LHBS labeled in a small plastic bag as 'Citric Acid'. On the very next sheet, '3. Water Adjustment' at the bottom where they ask for Acid adjustment, they do not have citric acid! Plus, it is only the entered as Ml/gal which further complicates it (for me).

Lastly, I have heard mention of taste thresholds in citric acid and how it can impart a fruity/estery quality . . .which I have to say I wouldn't hate if it were subtle. I had been trying to impart a slight citrus quality with hops to a golden strong but with little luck. Aroma in the fermenter was easy, but any lingering aroma and taste was nearly gone by bottling. In my head I was seeing a chance to bring down Ph slightly while possible adding a tiny bit of citrus even though it may not be common home brewing flavoring agent.

My water:
Ph 9%
Alkalinity/Bicarbonate (HCO3) 33 ppm
chloride (Cl-) 9 pm
sodium (Na+) 6 ppm
sulfates (SO4-2) 32 ppm
calcium (Ca+2) 27 ppm
hardness (around 45-50?)
magnesium (Mg+2) 6 ppm

7.5 gallons total water, ~1/2 in cooler MT with 10lbs all pale/pilsner (golden strong-trippel), rest in BK. Drain off mash into bucket, then dunk sparge bag in kettle. Kettle water at 165. I may change this to just do a second batch sparge of total remaining volume.
 

ajdelange

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Those numbers don't quite line up. For example, those levels of calcium and magnesium give a total hardness of 92 if interpreted as mg/L as the ion though they give a total hardness of 33 if interpreted as CaCO3. Not sure whether you mean alkalinity or bicarbonate under that listing though at pH 9 the two are actually almost equal. But in any event I can't get the profile to balance at all well under any set of assumptions I can come up with. Be that as it may, assuming that the alkalinity is in the 30's you should not need to acidify sparge water. But should you decide to the following amounts of 100% citric acid would be required per liter of water treated

Target pH ........ mg/L
6.00 ............. 18.9
5.80 ............... 22.4
5.60 ............... 25.5
 

Komodo

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As I mentioned in my earlier post, learning water chemisty is all new to me. I've reread your post several times, and afraid I don't understand. Under the alkalinity/ bicarbonate line, it very well may be a mistake and is just bicarbonate. I think i copied that down wrong.

From everything I've read and the Bru'n spreadsheet, it seems all I need is some calcium chloride. My last two batches had an astrigent quality that may just be young beer so far, but it seemed to me I was getting tannins or hop over-utilization or something. I was wondering about the acid, thinking maybe the higher ph in the dunk-sparge was causing problems.
 

mabrungard

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Thanks to AJ, Bru'n Water includes the full ability to assess the protonation potential of the acid used. So the issue of the triuprotic Citric acid is moot when using Bru'n Water.

The consistency of Bloomington water is fairly high since it comes from a decent sized reservoir. I see that the OP has been talking with the City to get the water quality, but something is a little off and should be resolved before putting too much faith in the water profile.

Bloomington water is primarily surface runoff and doesn't get too mineralized. So, its possible that the alkalinity is modest like the hardness is. That would suggest that mash acidification might not be needed for all beers. I do recommend that sparge water be acidified to bring the alkalinity a little lower. It won't take much acid.

I agree that the inclusion of other acids like citric, malic, or tartaric can be used to add nuances to the beer flavor that could be welcome. This should not be an issue for Bloomington water since the acid additions are likely small. It might be overbearing for brewers with high alkalinity and that would require experimentation and verification.

Enjoy!
 

ajdelange

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Sorry that I confused you. There are various practices used for reporting water chemistry. For example a water that contains 20 mg/L calcium ion may say A) "Ca 20 mg/L" or it may say B) "Ca 20 ppm" or it may say C) "Ca 50 ppm as CaCO3". All of those mean the same thing. Problems arise when a report assumes that you understand that C is meant and says "Ca 50 ppm" and you don't understand that it means 50 ppm as CaCO3. This is confusing and people posting their water values often throw us for a loop when they misinterpret the report. Another big one, given that Ward Labs does not report the amount of sulfate in a sample but rather the amount of sulfur in the sulfate in the sample. If your sulfate is indeed 32 mg/L SO4-- ion then that is one thing but if it is mg/L "as sulfur" that means the sulfate concentration is 3 x 32 = 96 mg/L.

If you put one molecule of calcium chloride (CaCl2) into water it will separate into calcium ion with an electrical charge of +2 and two chloride ions each with an electrical charge of -1 so the total charge from the added material is +2 + 2*(-1) = 0. This is the case for anything else added to the water by you or anyone else. So if you take a water analysis like the one you posted and add up all the positive charges and negative charges they must come to 0. In your report they don't and there are various reasons for this. An obvious one would be that I interpret Ca and Mg ppm as ppm as CaCO3 when those values are actually meant to convey mg/L. The other is that sulfate as sulfur and sulfate as sulfate could be confused. In the usual case bicarbonate content is approximately 61/50 times alkalinity but in your case the pH is 9 and alkalinity and pH are numerically close to one another at that pH. What I meant to say was that in applying all the various assumptions about what your numbers could mean I was not able to come up with any which gave me a net charge of 0. In real water reports there are always errors so one never comes up with exactly 0 but in yours I got imbalances of 0.5 - 0.6 mEq/L and that's a lot.

Error in interpretation could be responsible. Error is transcription is possible. Error in the laboratory is possible. Another strong possibility is that this report came from a water authority. Often they report seasonal (or other) averages and/or do tests at different times (e.g. measure calcium on Mondays and sulfate on Thursdays). This results in imbalance. Bottom line is that there are errors in this report and it can only be relied upon to give you an approximate picture of the water.

The approximate picture is of a fairly low mineral water. You shouldn't really need to add anything to this water though many would recommend some calcium chloride (and that wouldn't hurt). You would, for most beers, need to add some acid to the mash in order to get the mash pH into the correct range. Citric acid would do and, as I've noted before, used to be incorporated in many home brew recipies. Lactic is more commonly used today and I have to assume that's because of flavor though lactic certainly has a flavor of its own. Probably the biggest convenience with lactic is that is available sprayed onto (or grown on) malt (called "acidulated malt" or "sauermalz") and this is a very convenient form indeed as 1% of grist weight as sauermalz seems to pretty consistently lower mash pH by 0.1.

There is a Primer in the stickies at the top of this topic that may be of help.
 

Komodo

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Fantastic. That clears up much, and I will pursue a better clarification on my profile.

One final question. You said add acid "to the mash". Would there not be a benefit to doing an overall Ph adjustment from say 9 to 7 on the total water volume? This would have me putting Ph 7 into the mash, and having Ph 7 for the dunk sparge or boil or however I end up doing the process?

Update: accurate water profile coming . . .on the phone the woman asked what I wanted to know, when I said I was home brewing she said OOOHHH YEAH, I've made up a sheet just for you guys! I'l send it to you! Also, the sulfate question kinda threw her for a loop. She's checking into it.

Here it is. She said Ca is reported as CaO3:

Ph averages 9-9.2

Parameter Results (mg/l) Maximum Allowed (mg/l)
Alkalinity/Bicarbonate 30 No limit
Chloride 8.7 250 (secondary)
Sodium 7.5 No limit
Sulfates 32.5 250 (secondary)
Calcium 28 No limit
Hardness 44 No limit
Magnesium 3.9 No limit
 

ajdelange

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I said in the mash and even put it in italics to emphasize that it is mash pH which needs to be controlled and because a popular means of doing it is to add acidulated malt to the mash. Beyond that, Primer, spreadsheets, calculators and recipes aside, the best way to determine the amount of amount of acid required is to make a test mash in which a sample of the grist is doughed in with the water to be used, the pH checked and additions of acid made as required to bring the mash to the proper pH. If you used acid in any form other than sauermalz you could, of course, add the amount determined in the test mash (scaled to the size of the full mash) to the water when doing the main brew and that would take the water pH wherever it takes it. The key concept here is that you don't care what pH the water ends up at. You do care what pH the mash ends up at when exposed to that water.
 

Homercidal

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I said in the mash and even put it in italics to emphasize that it is mash pH which needs to be controlled and because a popular means of doing it is to add acidulated malt to the mash. Beyond that, Primer, spreadsheets, calculators and recipes aside, the best way to determine the amount of amount of acid required is to make a test mash in which a sample of the grist is doughed in with the water to be used, the pH checked and additions of acid made as required to bring the mash to the proper pH. If you used acid in any form other than sauermalz you could, of course, add the amount determined in the test mash (scaled to the size of the full mash) to the water when doing the main brew and that would take the water pH wherever it takes it. The key concept here is that you don't care what pH the water ends up at. You do care what pH the mash ends up at when exposed to that water.
Along those thoughts, I have understood that MASH pH is the critical factor, but also the sparge pH is important if your water is highly alkaline like mine is.

I treat them separately, because after the first lauter, the pH rises. Sparging with highly alkaline water would promote tannin extraction. Therefore I treat the sparge simply to prevent this. For people with less alkalinity, the sparge pH is probably not important.
 

ajdelange

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I suppose by analogy we could say that it is not the pH of the sparge water that is important but the pH of the collected wort at terminal gravity. Practically speaking though, as it's clear that runoff pH will never go above 6 if the sparge water pH is below 6, it is much less bother to acidify the sparge water to pH just below 6 than to repeatedly check the pH during collection. There is an alternative to adding acid and that it to add non alkaline (RO/DI) water to the available water.
 

mabrungard

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The Bloomington profile converted to straight mg/L units is as follows:

Ca: 11.2
Mg: 3.9
Na:7.5
HCO3: 30
SO4: 32.5
Cl: 8.7

I wouldn't put much faith in the decimal values and rounding is OK. The report balances within 0.2 meq/L which is OK. This is a soft water that is characteristic of limited groundwater inflow. Additional Ca would be a good idea for this brewing water.
 

ajdelange

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Also, the sulfate question kinda threw her for a loop. She's checking into it.
Not surprised. It threw me for a loop for a long time. Ward Labs is, AFAIK, the only lab that reports sulfate that way. One of the things I really like about Ward Labs is that they give total anion and cation charge at the head of the report. One might wish those numbers were closer to one another than they usually are but what do you want for 25 bucks? But I could never get the numbers they reported for any of the many reports I looked at - all posted here and in other forums. Then they started sending out reports by e-mail and one guy cut and pasted his e-mail so that the telltale -S in SO4-S came across and the light came on. Someone subsequently called Ward Labs and verified that they are indeed reporting "as Sulfur". They do the same for Nitrate (i.e. "as Nitrogen") and I'm sure the reason for it is that they serve the agricultural industry primarily where the concern is how many pounds of nitrogen per acre, how many pounds of sulfur...

I'd tell that nice lady not to worry about it. A water authority will be following APHA/ AWWA protocols and would not report "as sulfur".
 

Komodo

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Well, I did tell her not to worry...then she told me she had just received a homebrew kit as a gift! Let the worrying begin!! LOL
 
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