Not hitting target pH
Not hitting target pH
Hi
I am trying to brew a Reggwelter Robust Porter and using Brn'Water with the following inputs should have given me a mash pH of 5.4 but it is 5.7. I have tested the mash twice after 10mins and again after 20mins. Both give 5.7 with the wort cooled to below 25degC. I don't understand what has gone wrong. My last two brews have hit 5.4 following the exact same procedures.
My water profile is Ca 98.0 Mg 17.0 Na 7.6 (estimated to give a ion balance) SO4 121.3 Cl 41.4 NO3 11.9 F 0.2, Salfert Kit 136.0, water pH 7.5. This indicated Bicarb 165.4, Carb 0.2.
Grain Bill : Maris Otter 3.554Kg 5.5EBC, Crystal 60L 0.288Kg 120EBC, Wheat Torrified 0.434Kg 3.9EBC, Chocolate Malt 0.489Kg 950EBC, Roasted Barley 0.001Kg 1199.7EBC.
For 35L of water I added 3.96g Table salt and 6.08g of Calc Chloride flakes. I used CRS to try to bring the Alk down to 81 as the spreadsheet showed it should be but I didn't manage it. I added about 9ml of CRS and retested. Added a further 1.7ml and retested and no change so added another 1.7ml and still stuck at 90.
So my question is how can the spreadsheets prediction be so different to the outcome?
Thanks
Rob.
I am trying to brew a Reggwelter Robust Porter and using Brn'Water with the following inputs should have given me a mash pH of 5.4 but it is 5.7. I have tested the mash twice after 10mins and again after 20mins. Both give 5.7 with the wort cooled to below 25degC. I don't understand what has gone wrong. My last two brews have hit 5.4 following the exact same procedures.
My water profile is Ca 98.0 Mg 17.0 Na 7.6 (estimated to give a ion balance) SO4 121.3 Cl 41.4 NO3 11.9 F 0.2, Salfert Kit 136.0, water pH 7.5. This indicated Bicarb 165.4, Carb 0.2.
Grain Bill : Maris Otter 3.554Kg 5.5EBC, Crystal 60L 0.288Kg 120EBC, Wheat Torrified 0.434Kg 3.9EBC, Chocolate Malt 0.489Kg 950EBC, Roasted Barley 0.001Kg 1199.7EBC.
For 35L of water I added 3.96g Table salt and 6.08g of Calc Chloride flakes. I used CRS to try to bring the Alk down to 81 as the spreadsheet showed it should be but I didn't manage it. I added about 9ml of CRS and retested. Added a further 1.7ml and retested and no change so added another 1.7ml and still stuck at 90.
So my question is how can the spreadsheets prediction be so different to the outcome?
Thanks
Rob.
- Eric
- Even further under the Table
- Posts: 2920
- Joined: Fri Mar 13, 2009 1:18 am
- Location: Sunderland.
Re: Not hitting target pH
9 ml of CRS should (in testing does for me) reduce alkalinity by a total of about 1647mg CaCO3 which in turn would reduce alkalinity in 35 litres by 47mg/l to roughly the 90 you found.
A further 2 doses of 1.7ml would reduce average alkalinity to more or less 70mg/l, so perhaps the acid did its job but perhaps not sufficiently stirred for your sample to be typical. Also the droplet size from the syringe in the Salifert kit restricts the accuracy of the test and a combination of those two incline me to think your liquor's final alkalinity would be close to that target.
Should my sums be right, from acid treatment and added salts your liquor would have calcium at 145ppm, magnesium 17, sulphate 150 and chloride 218ppm and alkalinity 70ppm CaCO3. If used in a mash at a rate of between 2.5 and 3 litres per Kg of your chosen grist I would expect pH to be less than 5.7. I can't answer your question, maybe Martin might, but currently I'm far from convinced early mash sample readings with a pH meter are any value to the brewer. Recent testings by myself have suggested early wort samples are unstable when cooled, with pH rising quite rapidly in several such cases.
About 100 years at the Carlsberg laboratory Sorensen experimented with a galvanometer to measure ionic activity to create what became the pH scale which in turn led to the development of a more accurate electronic means of its measurement. (For centuries colour indicators existed but their use would never lead to a mathematical scale.) Since then chemists have explored the happenings in the mash to in turn predict outcomes. High alkalinity liquor was shown to cause raised mash pH and UK brewers have long used acid to reduce that alkalinity. German purity laws prohibited this simple procedure causing more thorough investigations where it was also found that some waters with low level alkalinity also gave rise to high mash pH because of the similarly low levels of calcium and magnesium. During and after WWII Kohlbach examined the effects of alkalinity, calcium and magnesium salts on a mash with low ion liquors to produce a formula taking all three into account. This is what has been called Residual Alkalinity, if the subject wasn't already sufficiently confused by duplicitous terminology. This formula was derived using low ion waters, possibly using a stepped mash with much less modified malts using pH readings taken at knockout for a style of beer that would lagered at low temperature for months, but is now used as a universal predictor of mash pH in every circumstance. I don't think it does work in every circumstance and especially so when extrapolated as far as it that for your porter.
One thing I do think is that your porter doesn't give a damn what Kohlbach thought nor what your meter found, made with that liquor and that alkalinity it will do you proud.
A further 2 doses of 1.7ml would reduce average alkalinity to more or less 70mg/l, so perhaps the acid did its job but perhaps not sufficiently stirred for your sample to be typical. Also the droplet size from the syringe in the Salifert kit restricts the accuracy of the test and a combination of those two incline me to think your liquor's final alkalinity would be close to that target.
Should my sums be right, from acid treatment and added salts your liquor would have calcium at 145ppm, magnesium 17, sulphate 150 and chloride 218ppm and alkalinity 70ppm CaCO3. If used in a mash at a rate of between 2.5 and 3 litres per Kg of your chosen grist I would expect pH to be less than 5.7. I can't answer your question, maybe Martin might, but currently I'm far from convinced early mash sample readings with a pH meter are any value to the brewer. Recent testings by myself have suggested early wort samples are unstable when cooled, with pH rising quite rapidly in several such cases.
About 100 years at the Carlsberg laboratory Sorensen experimented with a galvanometer to measure ionic activity to create what became the pH scale which in turn led to the development of a more accurate electronic means of its measurement. (For centuries colour indicators existed but their use would never lead to a mathematical scale.) Since then chemists have explored the happenings in the mash to in turn predict outcomes. High alkalinity liquor was shown to cause raised mash pH and UK brewers have long used acid to reduce that alkalinity. German purity laws prohibited this simple procedure causing more thorough investigations where it was also found that some waters with low level alkalinity also gave rise to high mash pH because of the similarly low levels of calcium and magnesium. During and after WWII Kohlbach examined the effects of alkalinity, calcium and magnesium salts on a mash with low ion liquors to produce a formula taking all three into account. This is what has been called Residual Alkalinity, if the subject wasn't already sufficiently confused by duplicitous terminology. This formula was derived using low ion waters, possibly using a stepped mash with much less modified malts using pH readings taken at knockout for a style of beer that would lagered at low temperature for months, but is now used as a universal predictor of mash pH in every circumstance. I don't think it does work in every circumstance and especially so when extrapolated as far as it that for your porter.
One thing I do think is that your porter doesn't give a damn what Kohlbach thought nor what your meter found, made with that liquor and that alkalinity it will do you proud.
Without patience, life becomes difficult and the sooner it's finished, the better.
Re: Not hitting target pH
Thanks Eric for your reply and history lesson. As one gets older history plays a bigger part.
You are probably right about the CRS and it's final effect. I was only using the two drop tests so accuracy would play a part. I did though mix well by running the pump.
My mash schedule was mash in at 38degC, protein rest at 52deg for 10 mins, then 45mins at 67deg, 30min at 73deg and finishing with 10min at 78deg. I tested the pH after the protein rest and then after another 10 mins.
As I said before I have only ever tested the pH on my last two brews and they were as predicted.
I only managed to reach SG1062, the target was 1063 and to do this I sparged less. 4litres less in fact. Would the higher mash pH have affected the mash efficiency do you think?
Rob.
You are probably right about the CRS and it's final effect. I was only using the two drop tests so accuracy would play a part. I did though mix well by running the pump.
My mash schedule was mash in at 38degC, protein rest at 52deg for 10 mins, then 45mins at 67deg, 30min at 73deg and finishing with 10min at 78deg. I tested the pH after the protein rest and then after another 10 mins.
As I said before I have only ever tested the pH on my last two brews and they were as predicted.
I only managed to reach SG1062, the target was 1063 and to do this I sparged less. 4litres less in fact. Would the higher mash pH have affected the mash efficiency do you think?
Rob.
- Eric
- Even further under the Table
- Posts: 2920
- Joined: Fri Mar 13, 2009 1:18 am
- Location: Sunderland.
Re: Not hitting target pH
Sorry if my reply was like a school lesson, just your question sitting there for a day and more unanswered despite a forum visit by that spreadsheet's author got me going a bit. I suppose a lot of history has happened in my time.
Complicated mash for a porter, why was that? If you were using a larger than necessary amount of liquor during that process the extra alkalinity present would have an adverse influence on the pH value.
No, the mash pH will not play any major part in potential extract efficiency. If it is too high it does make the extraction of unwanteds more likely and in such cases it would be wise not to attempt washing out every bit of the sugars as the last runnings would be heavy with tannins and the like. All in all this means efficiency should be one of your last concerns, use extra grain and stop when you've got what you need. Set about getting the most extraction later when you will more than make up for all the early losses having avoided any potential problems of over extraction.

Complicated mash for a porter, why was that? If you were using a larger than necessary amount of liquor during that process the extra alkalinity present would have an adverse influence on the pH value.
No, the mash pH will not play any major part in potential extract efficiency. If it is too high it does make the extraction of unwanteds more likely and in such cases it would be wise not to attempt washing out every bit of the sugars as the last runnings would be heavy with tannins and the like. All in all this means efficiency should be one of your last concerns, use extra grain and stop when you've got what you need. Set about getting the most extraction later when you will more than make up for all the early losses having avoided any potential problems of over extraction.
Without patience, life becomes difficult and the sooner it's finished, the better.
Re: Not hitting target pH
[quote="Eric"Complicated mash for a porter, why was that? If you were using a larger than necessary amount of liquor during that process the extra alkalinity present would have an adverse influence on the pH value.[/quote]
If you hadn't guessed already, I have a BM so complicated mashes are easy peasy. There was 4.766kg of grains which went into 25litres.
Rob.
If you hadn't guessed already, I have a BM so complicated mashes are easy peasy. There was 4.766kg of grains which went into 25litres.
Rob.
- Aleman
- It's definitely Lock In Time
- Posts: 6132
- Joined: Sun Jun 03, 2007 11:56 am
- Location: Mashing In Blackpool, Lancashire, UK
Re: Not hitting target pH
As long as it's between 5.2 and 5.7 I certainly do not worry about it
- Eric
- Even further under the Table
- Posts: 2920
- Joined: Fri Mar 13, 2009 1:18 am
- Location: Sunderland.
Re: Not hitting target pH
My car's a BMW but I drive it through the town at 30mph.Soay4699 wrote:If you hadn't guessed already, I have a BM so complicated mashes are easy peasy. There was 4.766kg of grains which went into 25litres.Eric wrote:Complicated mash for a porter, why was that? If you were using a larger than necessary amount of liquor during that process the extra alkalinity present would have an adverse influence on the pH value.
Rob.
Without patience, life becomes difficult and the sooner it's finished, the better.
Re: Not hitting target pH
Quite right too. But I compare brew days with track days.Eric wrote:My car's a BMW but I drive it through the town at 30mph.Soay4699 wrote:If you hadn't guessed already, I have a BM so complicated mashes are easy peasy. There was 4.766kg of grains which went into 25litres.Eric wrote:Complicated mash for a porter, why was that? If you were using a larger than necessary amount of liquor during that process the extra alkalinity present would have an adverse influence on the pH value.
Rob.
- Eric
- Even further under the Table
- Posts: 2920
- Joined: Fri Mar 13, 2009 1:18 am
- Location: Sunderland.
Re: Not hitting target pH
Fair's fair, just curious why your excellent piece of equipment was put to that mode for that beer? As one who nearly always does a single temperature infusion mash for 90 minutes I'd be concerned about the time allowed for saccharification with that particular grist. Also wonder if the process might negate some of the purposes for which the torrified wheat and choc malt were included while not at this time thinking the rest would benefit a Porter.Soay4699 wrote: Quite right too. But I compare brew days with track days.
Anyway, the proof of course is yet to come. Best wishes.
Eric.
Without patience, life becomes difficult and the sooner it's finished, the better.
Re: Not hitting target pH
Fair cop. This was only my tenth AG, the recipe was someone elses and the same for the mash schedules.Eric wrote:Fair's fair, just curious why your excellent piece of equipment was put to that mode for that beer? As one who nearly always does a single temperature infusion mash for 90 minutes I'd be concerned about the time allowed for saccharification with that particular grist. Also wonder if the process might negate some of the purposes for which the torrified wheat and choc malt were included while not at this time thinking the rest would benefit a Porter.Soay4699 wrote: Quite right too. But I compare brew days with track days.
Anyway, the proof of course is yet to come. Best wishes.
Eric.
It is interesting what you say about allowing enough time for this particular grist etc. I have not yet come across a definitive guide for creating mash schedules depending on the grain bill used etc. I was only considering 66 for light body, 67 for medium body and 68 for full body. I think it is certainly time for me to re-read John Palmer Chap 14.
Which brings me back to the mash pH. According to JP's Enzyme range chart 5.7 would mean hardly any enzymes would have been happy.
Rob.
- Aleman
- It's definitely Lock In Time
- Posts: 6132
- Joined: Sun Jun 03, 2007 11:56 am
- Location: Mashing In Blackpool, Lancashire, UK
Re: Not hitting target pH
Good job British Enzymes don't read Palmer either then 

- Eric
- Even further under the Table
- Posts: 2920
- Joined: Fri Mar 13, 2009 1:18 am
- Location: Sunderland.
Re: Not hitting target pH
As Aleman advised, 5.7 will be fine and in any case don't get obsessed with pH, there are many more important aspects even though a BM will deal with many of them, it won't with all.
This is not the place to go into detail about the mash, information can be found elsewhere on JBK. Click on Grain Brewing at the top of the page, then Mashing to see Jim doing it manually and give a good basic grounding. Reading JP is the norm in present day, it's there, but there are better scripts.
This is not the place to go into detail about the mash, information can be found elsewhere on JBK. Click on Grain Brewing at the top of the page, then Mashing to see Jim doing it manually and give a good basic grounding. Reading JP is the norm in present day, it's there, but there are better scripts.
Without patience, life becomes difficult and the sooner it's finished, the better.
Re: Not hitting target pH
The reason I was looking into the mash pH being high was because I previously had one bad batch. The beer tasted awful. It had a sour vinegar flavour that didn't change with ageing. Please bare with me as I do not have a trained pallet.
There were two areas where I went wrong I believe, one was under pitching (used a single vial of WLP005 pitched straight in) and the other was I suspected I had the mash pH wrong. Working back from the actual water treatment I did it showed in the calculators that the predicted mash pH would have been 5.7. So I bought a pH meter off ebay and the next three brews all hit the target of 5.4 and made very nice beers.
So not unnaturally when this latest brew read 5.7 I panicked.
There were two areas where I went wrong I believe, one was under pitching (used a single vial of WLP005 pitched straight in) and the other was I suspected I had the mash pH wrong. Working back from the actual water treatment I did it showed in the calculators that the predicted mash pH would have been 5.7. So I bought a pH meter off ebay and the next three brews all hit the target of 5.4 and made very nice beers.
So not unnaturally when this latest brew read 5.7 I panicked.
- Eric
- Even further under the Table
- Posts: 2920
- Joined: Fri Mar 13, 2009 1:18 am
- Location: Sunderland.
Re: Not hitting target pH
With one exception, one I've never experienced, I cannot think that any beer made properly using untreated water from a UK domestic supply could be labelled as bad. That exception is the often criticised influence of chlorine which can be totally eliminated by a portion of a Campden tablet in the liquor at the start for brews of your and my lengths.Soay4699 wrote:The reason I was looking into the mash pH being high was because I previously had one bad batch. The beer tasted awful. It had a sour vinegar flavour that didn't change with ageing. Please bare with me as I do not have a trained pallet.
There were two areas where I went wrong I believe, one was under pitching (used a single vial of WLP005 pitched straight in) and the other was I suspected I had the mash pH wrong. Working back from the actual water treatment I did it showed in the calculators that the predicted mash pH would have been 5.7. So I bought a pH meter off ebay and the next three brews all hit the target of 5.4 and made very nice beers.
So not unnaturally when this latest brew read 5.7 I panicked.
Get your water significantly wrong and the mash pH and at all subsequent stages will be in the wrong region. Enzymes will struggle, yeast will struggle, beerstone can form in your vessels, beers will take longer to, or won't, clear and hazes will be ever present and a great many more imperfections than should be listed here besides. The finished beer's taste will be different, but not what should ever be called bad but rather warrant critical comment. Both hops and malts can be muted or harsh while flavours not normally present can dominate and any minor bacterial contamination that would otherwise fail to influence the result might survive or thrive to eventually ruin the beer.
Getting mash pH bang on target will no more guarantee a good beer than would a good drive off the first tee guarantee a par round of golf. It is possible to make the worst of beer from the best of water and there is no perfect single water composition. Small differences in a water's mineral content will make small differences in the final beer, bigger differences make bigger differences, that's all.
You won't be unique in pitching too little such as that from a single phial of White Labs yeast, I've done it many times.
The most likely cause of bad beer is infection, but it's natural to look for other causes when thinking all precautions have been taken. There would always seem to be some suitable alternative cause that is in vogue at any particular time, water is one such case.
The water treatment described in your first post was more than good enough to make a decent porter and it would seem you have a grasp of that subject. I didn't like your mash schedule and don't know what to expect it to do to the finished beer as I'd be concerned how much conversion took place in that 45 minutes with such a significant proportion of the grist providing no working enzymes and that excess starch may have reached the finished product. All that wouldn't make bad beer, a poorer beer than could have been maybe.
At this stage I'd simplify the recipe and process. Use CRS to get the alkalinity down to about 30 ppm CaCO3 and add a bit calcium with a suitable salt addition. Try 95% pale and 5% of something to give just a bit of of a personal twist in single stage mash for 90 minutes. Boil for 90 mins with some hops to bitter, some for 20 mins for flavour and some at flameout for aroma, none of them a New World mind blowing dynamite style. That machine of yours should turn out a beer that makes you want to stand on your roof and tell the world what you've done. If it doesn't it's nothing to do with water or pH, whatever they were.
Editted to remove a factor of 10 error.
Last edited by Eric on Wed Feb 11, 2015 6:37 pm, edited 1 time in total.
Without patience, life becomes difficult and the sooner it's finished, the better.
Re: Not hitting target pH
Thanks Eric. Quite a post.
I have just lost all of my long reply. Dam... I hate web browsers. I will try and remember some of what I typed.
I take on board all that you have said.
I ruled out infection on the grounds that one out of nine going bad would be odd given that I followed the same cleaning procedures and also that there were no visible signs or wrong smells.
So far I have brewed mostly porters and one mild (which I hope to take to the Morley competition later this month) all of which would have necessitated that climb onto the roof. But the one disaster was Adnams Broadside, a strong bitter.
I have just lost all of my long reply. Dam... I hate web browsers. I will try and remember some of what I typed.
I take on board all that you have said.
I ruled out infection on the grounds that one out of nine going bad would be odd given that I followed the same cleaning procedures and also that there were no visible signs or wrong smells.
So far I have brewed mostly porters and one mild (which I hope to take to the Morley competition later this month) all of which would have necessitated that climb onto the roof. But the one disaster was Adnams Broadside, a strong bitter.
Do you mean 30ppm?Eric wrote: At this stage I'd simplify the recipe and process. Use CRS to get the alkalinity down to about 300 ppm CaCO3 and ....