Brew Day Water pH

[MHB]

I don't know the answer - hence the suggestion that you try it and let us know what happens.
I use lactic acid for a number of reasons and don't find any negative flavour issues. I have also read that Phosphates react with Calcium salts to remove both from the water, I have also noted that most brewing texts recommend Lactic, Sulphuric and Hydrochloric acids even providing equations and/or tables to tell you how much to use to achieve desired pH adjustments. But I haven't seen any such for Phosphoric Acid.

As a favor put a teaspoon of CaCl2 in a glass, ad some phosphoric and see what happens, If nothing then fine no problem, if it forms a cloud and precipitates then we all have something to think about. I would do it myself but don't have any phosphoric acid to hand.
Mark

 

[timmi9191]

Palmers "water" provides said equations etc re phosphoric acid

 

[wobbly]

I have also noted that most brewing texts recommend Lactic, Sulphuric and Hydrochloric acids even providing equations and/or tables to tell you how much to use to achieve desired pH adjustments. But I haven't seen any such for Phosphoric Acid.

As a favor put a teaspoon of CaCl2 in a glass, ad some phosphoric and see what happens, If nothing then fine no problem, if it forms a cloud and precipitates then we all have something to think about. I would do it myself but don't have any phosphoric acid to hand.
Mark

On the first part of your post the following is taken from Brukaser's paper part 3 on mashing where he lists Phosphoric Acid amounts.

As to the other question about adding a teaspoon of CaCl2 to a glass of water this would in my view be totally unrepresentative for the following reason

1 teaspoon is approx 5 grams and a glass of water is approx 250mls therefore adding 5grams to 250 mils would equate to 20g per lt or about 4600ppm of calcium and then adding some Phosphoric Acid (drops/mils??) is likely to produce some sort of result that you would not see in a realistic brew schedule
Maybe I am miss understanding what you are suggesting but I can't see how it would be representative of what the impact of 3 or so mls of Phosphoric Acid in a mash of 5.5 kg of grain in 32lt of mash water would be

Again not trying to take the piss just trying to better understand water treatment

Cheers

Wobbly

 

[MHB]

Fair Cop
I should have said professional brewing texts, where what I said stands, Braukaiser is a pretty respectable source and Water isn't at all bad so odds on they are right.

As to the other question about adding a teaspoon of CaCl2 to a glass of water this would in my view be totally unrepresentative for the following reason
1 teaspoon is approx 5 grams and a glass of water is approx 250mls therefore adding 5grams to 250 mils would equate to 20g per lt or about 4600ppm of calcium and then adding some Phosphoric Acid (drops/mils??) is likely to produce some sort of result that you would not see in a realistic brew schedule
Maybe I am miss understanding what you are suggesting but I can't see how it would be representative of what the impact of 3 or so mls of Phosphoric Acid in a mash of 5.5 kg of grain in 32lt of mash water would be

The chemistry would be the same, more dilute sure but the same reactions would/could take place just perhaps not as visibly. We all know that a very small (3mL in 32L) makes a pretty big and easily measured/tasted difference - or we wouldn't be doing it, the suggestion was purely to see if relatively insoluble Calcium Phosphate is formed, if it is it matters, if not then no problem.

Believe me I am still working my through some of the concepts behind water chemistry and am far from thinking I have all the answers.
No problem with add required amounts of this or that to achieve desired results, still a way to go on the why and how it works.
mark

 

[wobbly]

I assume your concerns with using Phosphoric Acid for pH adjustment of the mash is/has something to do with the possibility of it precipitating calcium out of the mash

Martin Bruingard on the American Home Brewing Association Forum had this to say on the subject of precipitating calcium in the mash because of using Phosphoric Acid to adjust mash pH

Phosphoric acid is perfectly fine for pH adjustment. There is a myth circulating that adding phosphoric acid causes more calcium precipitation in the mash. Since wort typically contains on the order of 1% (which is 10,000 ppm) phosphatic compounds, adding a 100 ppm of orthophosphate ions to the mash is not going to appreciably change the amount of precipitation of calcium in the mash.

So it would appear that your concerns may not be founded

Wobbly

 

[MHB]

Agreed, like I said it isn't discussed in professional brewing literature and I have heard concerns about it precipitating Ca.
Maybe the cost of Phosphoric is the main issue, it is way more expensive than hydrochloric or sulphuric.
That 1% phosphatic compounds sounds very high - will have to look at that, and will get some Phosphoric acid and see how it reacts.
Mark

 

[wobbly]

Not sure about the cost but maybe using either Hydrochloric or Sulphuric is because they will contribute Chloride or Sulphate ions respectively to the mash and therefore not require the use of so much Gypsum or Calcium Chloride

Grain and Grape list 250ml bottles of 88% Lactic Acid for $9.90 and 250ml botles of 85% Phosphoric Acid at $8.00 and I understand that this costs may not be representative of what the cost could/would be on a commercial scale or how there compare with with the cost of Hyrdochloric and Sulphuric

Wobbly

 

[MHB]

My local has 500mL of 80% Lactic (in a lined chemical/poison bottle with a child proof cap - both cost extra) for $12.95 which looks like a pretty good deal.
I doubt that anyone would choose the acid on that basis, as you are looking for a balance of Ca, Mg, Cl and SO4, which is one of the reasons I use Lactic (and I suppose the same applies to Phosphoric), it doesn't change the Cl/SO4 balance at all, just the pH and adds a little more of something that is already there in fairly large amounts. Reportedly about 90% of the acidity in a mash comes from naturally occurring bacterial lactic acid, from what you reported there is even more phosphates there than lactic.
Industrial sized quantities of Hydro Chloric and Sulphuric Acids are very much cheaper than either Lactic or Phosphoric - I have costed them in 20-25L size quantities - and its like a quarter of the price.
Mark

 

[wobbly]

Whist this is all very interesting stuff it is starting to go off topic from my original inquiry which was "When to add acid to the mash for pH control"

In Gordon Strong's book Brewing Better Beers and this article by AJ deLange http://www.wetnewf.org/pdfs/alkalinity-reduction-with.html they both talk about the procedure adopted by Serra Nevada Brewing where they adjust all of their brewery water to a pH of 5.5 by using Phosphoric Acid. Their raw water is reported to be 76ppm Alkalinity and 25ppm Calcium which is just about right on for my potable/tap water.

Now I am still trying to get my head around all the subtilety of mash pH control but does this indicate that in their case they don't need to undertake further mash pH adjustments once the grain is added?

Is there some fundamental point I am missing in this?

Wobbly

 

[timmi9191]

Adjustments to water are not just about the mash ph. Sulphate levels, sulphate to chloride ratio, the levels of various ions all play a part in the final flavour profile of what you are trying to produce.

I think you might be expecting an answer that 1+1=2 therefore that is what you will always do. There are so many variables that there is no one simple answer. Do your research, read books on the topics (which you appear to be doing) and put the theory into practice. Experiment a little, use salt and no acids, use acids and no salts, see what you like best.

As a result of research and practice, I create a wAter profile particular to the style I'm brewing and use acidulated malt to adjust ph. I then use phosphoric acid to acidify the sparge water. Is that a perfect process, probably not, but it's improved my beers and efficiency.

 

[wobbly]

Thanks for that

I have briefly read part of the Water Book and a lot of what AJ deLange and M Bruingard have to say on brewing water, both mash and sparge, and have what I consider at best a basic understanding of the theory of how variations in CaCl2, CaSo4 and MgSo4 and CaCl2/Caso4 ratio will impact on the final beer. I also understand the process of using Acid (Pos, Lactic, Sulphuric, Hydrochloric etc) to reduce Alkalinity in the mash and the importance of doing that

My thirst for information was when to best add the acid to the mash liquid and was any point more beneficial than another.

As I said in an earlier post maybe it doesn't make any difference as long as you end up with the mash at your targeted pH

Wobbly

 

[timmi9191]

Make adjustments based on predictions using a tool like bru'n prior to dow in.

Test mash ph about 15 mins after dow in using a calibrated ph meter, preferably accurate to 2 decimal places. Ensure the sample of wort is cooled to 25 degrees. Use acid to adjust mash ph if necessary at that time.

 

[manticle]

Wobbly - add at the beginning and adjust if necessary 10-15 mins in.
As far as I understand, the mash buffers itself against pH change quite quickly and appropriate pH is important for enzymatic function so earliest is best.
Beyond that, don't stress too much unless your beers are shit or you have access to HPLC.

 

[wobbly]

Don't have any access to "High Performance Liquid Chromatography" equipment so for my next brew I will add some Phosphoric Acid prior to Dough-In to achieve a mash liquid pH of 5.5 (as Serra Nevada does) and then Dough-In with my typical grain bill and check after 15 mins and see what if any further adjustment is required

Not stressing just following a "Rabbit Down a Burrow" out of personal interest/education/knowledge

Wobbly

 

[Black n Tan]

so for my next brew I will add some Phosphoric Acid prior to Dough-In to achieve a mash liquid pH of 5.5 (as Serra Nevada does) and then Dough-In with my typical grain bill and check after 15 mins and see what if any further adjustment is required

Wobbly

Wobbly I and many have said this before that water pH is a poor predictor of mash pH, but I am not sure you have yet to appreciate this. Sierra Nevada have a certain water profile and know that if they adjust the water to pH x it will translate to a mash pH y given a certain grain bill and salt additions. You have different water so don't expect that getting your water to pH5.5 will magically result in a mash pH of 5.2. As I said earlier when I used straight lactic acid in my water the pH measured 3.5 (may be even less, but can't remember exactly) and my mash pH hit 5.2. If I had target a water pH of 5.5, my mash pH would have been much higher. You need to understand the residual alkalinity of your water which can't be measured by the pH of water.

 

[wobbly]

Thanks for your further input/comments

The SN practice of adjusting all the water that comes into the brewery to pH 5.5 from what I have read is for a number of reasons

• Corrosion control - Boilers - Pipes etc
• Water discharge requirements to meet certain environmental requirements
• Sparge water and
• Something to do with Mash liquid

Nothing I have read/researched indicates what else SN do with the pH 5.5 water being used in the mash. They may use a high percentage of Acid Malt in the grain bill or they may use more Phosphoric Acid to trim the mash after Dough-In. I don't know and have been unable to find out and not that it is important just interesting
I understand that adjusting my mash water to say pH 5.5 prior to Dough-In may/will not result in my mash being at target say pH 5.2 - 5.3
I understand what you experienced with your water by adding however much Lactic Acid you added prior to Dough-In and from what I understand Melbourne water generally is very soft where as mine according to Bru'n has a calculated residual alkalinity of 53 which will have to be treated and if you consider what AJ deLange had to say in the above reference if you adjust your brew water to pH 5.5 then no further adjustment should be necessary to counter the remaining small amount of residual alkalinity as indicated in the following copied from that reference

I acknowledge that the example here is for a starting alkalinity of 76ppm where as mine is less than that at 53 so may not require as much Phos acid but I interpret the the outcome to be very similar - Maybe I am missing the boat totally and my next brew will/should set me straight on the matter.

Example
It has been reported that Sierra Nevada, consistent with the idea given here, treats all it's water to pH 5.5 with phosphoric acid. Chico water has average alkalinity of 76 ppm as calcium carbonate and pH which can be as low as 6.5 or as high as 7.9. Calcium content is 25 mg/L.

The chart below indicates what the effects of this may be. The curves plot the alkalinity that remains when water with alkalinity of 100 ppm as CaCO3 and pH as given on the horizontal axis is treated with acid until the pH reaches the value which corresponds to the particular curve as indicated in the legend. Solid curves with open symbols represent treatment with phosphoric acid and curves just below them in the same color represent sulfuric acid (or any other strong acid though the calculations were done for sulfuric - note that lactic acid could be considered strong in this application). Let's assume that SN measures pH of 7.2 (right in the middle of the range) on a given brew day and wants to acidify to pH 5.5 with a strong acid (sulfuric, hydrochloric, lactic or a blend of these). The 5.5 pH curves are red. The thin solid curve is the strong acid curve. Entering the chart on the bottom axis at pH 7.2 and reading up we see that were the alkalinity 100 the alkalinity remaining would be about 15 and conclude from this that the amount of alkalinity remaining for an actual alkalinity of 76 would be 15% of 76 or 11.4 ppm as CaCO3.

If mashing at pH 5.5 the alkalinity of the water has been satisfactorily dealt with. No additional acid will be needed to overcome the remaining alkalinity. Remember that alkalinity is measured by titrating to an end point pH of 4.5 or so. Were we to titrate from 5.5 to 4.5 we would indeed need extra acid in amount equal to 11.4/50 mEq/L.

So based on this example the remaining alkalinity in my brew water which started at 53 would now be something like 15% of 53 which equals about 8 and therefore not something to have to worry about

Cheers

Wobbly

 

[timmi9191]

Can you list your water report, the grain bill and your mash and sparge water volumes.

Oh, and the style of beer you are brewing

 

[wobbly]

The information I have on the potable water is a report from the supply authority which is based on "their words" a range of analysis results for the past two years and the mean of the results are what I use.
Alkalinity as CaCo3 77, Calcium 25, Chloride165, Magnesium 5.5, Potassium 3.8, Sodium 105, Sulphate 23 pH 8.0 I dilute this with around 80% rain water to "even out the averages" which in Bru'n I assume is the same as RO water as it will still have some salts etc.
Brewing Salts 3.8g Gypsum, 4.5g Calcium Chloride. Bru'n Water prediction in ppm - Calcium 60, Mgo 0.5, Sodium 15, Sulphate 64, Chloride 75, So4/Cl ratio 0.8
Grain Bill for a typical Pale Ale 4kg BB Ale Malt, 1kg Wyermann Munich1, 300g BB Wheat, 250g Carapils, 100g Acid Malt
I brew full volume mash no sparge so water volume is 38lt and check mash pH about 10/15 mins after Dough-In and currently then add Phosphoric Acid (generally about 1.5 to 2 mls) as required to get to target mash pH
Bru'n Water predicts a mash pH of 5.34 with the addition of 1.8mls of 85% Phosphoric Acid (which is a bit high) which I check with a calibrate pH meter

My line of inquiry isn't about being able to understand how and when to add brewing salts and/or how obtain the target mash pH but is there a difference in the mash pH depending on when you add the Acid

As stated above AJ deLange "Implies" that SN adjust there water to 5.5 prior to Dough-In and is silent on if any further acid adjustment is undertaken similarly Gordon Strong in his book Brewing Better Beers also follows a similar procedure eg on page 150 he states he uses RO water and treats his mash water with Phosphoric Acid to achieve a pH around 5.5 and then adds his brewing salts. He then checks his mash pH and sometimes adds salts to the boil. Again he is silent on when he adds the grain

I understand Alkalinity (and RA) are strong buffers and can have significant impact on how much Acid is required to move/lower the mash pH - The higher the alkalinity the greater the amount of acid require to achieve a particular mash pH. So if your mash water has low/very low alkalinity and associated pH of around 5.5 does it follow that it will not be necessary to further acid post Dough-In depending on the slat additions of course

Cheers

Wobbly

 

[timmi9191]

Firstly a mash Ph of 5.34 at 25 degrees isnt too high, its well within an ideal range.

Next, I have used your water report and grain bill. I assume when you say full batch you are aiming for a final volume of 23 litres.

Aiming for a pale ale water profile as suggested by BrU'n (granted it doesnt hit the targets exactly but its pretty close) I would be adding:
Gypsum (CaSO4) 16.7g Epsom Salt (MgSO4) 5.7g Calcium Chloride (CaCl2) 1.5g

This gives a predicted mash Ph of 5.4. No acidification should be required.

I would add the salts pre dough in. Check Ph 15 mins later. Then add acid if necessary, but it is unlikely.

As B/T and others have advised you, do not focus on pre mash Ph. I know its quoted that is what S.N do, but I am sure they know conclusively what their water and malt compositions are and know the resultant mash Ph and water chemistry inside out. Having said that I serious doubt they would treat all their water the same, ie acidifiying water for a stout in the same way does not compute.

To answer your question (which I believe is counter intuitive as your focus should just be on the mash ph) from my knowledge, it would not make a difference but may effect the rate at which the mash Ph establishes and stabilizes and some of the initial conversations.

 

[Black n Tan]

I understand Alkalinity (and RA) are strong buffers and can have significant impact on how much Acid is required to move/lower the mash pH - The higher the alkalinity the greater the amount of acid require to achieve a particular mash pH. So if your mash water has low/very low alkalinity and associated pH of around 5.5 does it follow that it will not be necessary to further acid post Dough-In depending on the slat additions of course

Cheers

Wobbly

I suspect both the examples you have given used RO water and as such alkalinity was effectively 0, so the water would contain effectively no buffering power. I would think they would still use some acid and salts to get the mash pH right, especially for a lighter grist (no crystal or roast). In my situation my water alkalinity is 12 and my RA is 8 (this is prior to adjustment, but is similar to what you get after adjustment), but i still needed to add significant acid to get the mash pH to 5.2 (8mL 88% lactic acid for 55L) which resulted in water pH of mid 3's. So I don't think adjusting the water pH to 5.5 will give you a mash pH of 5.2, without further additions of acid, but hey there is only one way to be sure.