How accurate are ph indicator strips?

(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
Top Cat
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How accurate are ph indicator strips?

Post by Top Cat » Thu Oct 08, 2020 1:03 pm

Hi all.
I’ve been using these things for a few years now, and over the last few brews I am doubting their accuracy.
My last water report claimed an average ph level of 7, sulphate 50ppm chloride 45ppm, measuring with the strips and comparing the colour to the chart it is more like 6.
When mashing, after about 15 minutes a reading is taken, which is normally between 5 and 5.4.
This is with charcoal filtered water. For 25 ltr of beer, I like to add calcium sulphate (10g) and calcium chloride (5g) but add it at sparge time as I’m not sure and don’t want the ph to drop any more below 5 if salts are added to the mash water.
I normally brew pale ales and bitters.
Does anyone have any advice on a decent meter I could purchase if the general opinions are I’m working with duff equipment.

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Re: How accurate are ph indicator strips?

Post by Jocky » Thu Oct 08, 2020 2:42 pm

You don’t need to care about starting water pH. You only need to think about the mash pH initially. Later on you might want to measure pH further through the process too.

I found the narrow range pH strips impractical for brewing. They had a range of colours from brown to yellow, but by the time they’re dipped in brown wort it was quite difficult to tell what they are meant to be with any accuracy.

I use the Voltcraft pH-100 ATC meter, but I bought it when it was less than half the price it’s available for now.
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orlando
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Re: How accurate are ph indicator strips?

Post by orlando » Thu Oct 08, 2020 2:51 pm

Have you had a proper water analysis done? If you're going to get serious with water treatment this is a must. You may find you don't need a charcoal filter at all.
I am "The Little Red Brooster"

Fermenting: Riders On The Storm
Conditioning: He Ain't Heavy, He's My Brother (Wee Heavy) till December.
Drinking: Kings & Queens (Eldridge Pope Royal Oak clone), Gyle brewed Little Red Ruth(ster) & Red(Ruth)Rain 1867 recipe, From Russia With Love (RIS)

Up Next: Stout! In The Name Of Love, Elusive Butterfly
Planning: Autumn drinking Beer

Top Cat
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Re: How accurate are ph indicator strips?

Post by Top Cat » Thu Oct 08, 2020 4:55 pm

Jockey, fully understand that water ph before mashing is different to mash ph due to the malts bringing it down, and obviously that’s the important bit. I just wanted to know in the most simplest way how accurate I am working to.
I think you confirm my feelings on the strips, might have to dip my hand in my pocket for something more elaborate!

Orlando, I should get the water checked properly the one I had from South Staffs was basic and not revealing enough for brewing purposes.
Regarding the filter, I used this purely by default after a long sabbatical from brewing. When I moved properties I didn’t have the filtration system for about three brews and to be honest the results were inferior beer.
Reading water treatment posts on this forum gives me the impression I should have been a chemist, so I try not to blind myself with science, but a little helps!

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Eric
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Re: How accurate are ph indicator strips?

Post by Eric » Thu Oct 08, 2020 10:20 pm

Top Cat wrote:
Thu Oct 08, 2020 1:03 pm
Hi all.
I’ve been using these things for a few years now, and over the last few brews I am doubting their accuracy.
My last water report claimed an average ph level of 7, sulphate 50ppm chloride 45ppm, measuring with the strips and comparing the colour to the chart it is more like 6.
When mashing, after about 15 minutes a reading is taken, which is normally between 5 and 5.4.
This is with charcoal filtered water. For 25 ltr of beer, I like to add calcium sulphate (10g) and calcium chloride (5g) but add it at sparge time as I’m not sure and don’t want the ph to drop any more below 5 if salts are added to the mash water.
I normally brew pale ales and bitters.

Does anyone have any advice on a decent meter I could purchase if the general opinions are I’m working with duff equipment.
Today I suspect few available pH strips are suitable for brewing purposes. A sutable pH meter is likely cheaper than a pack of usable strips.

pH of water is unimportant. Mine is usually 6.0 direct from the tap. Exposed to air, an hour later it can measure above 7. Heated and mixed with pale malt, whether the water be pH 6 or 7, the wort produced will be pH 6.0 or 6.1. Water from my eldest daughter's home is usually around pH 5. Kept in a sealed container, heated then used to mash pale malt, the wort then produced will be pH 5.9 to 6.0. Leave pH of untreated water to chemists, I'm sure they'll have lots of reasons for measuring it that brewers .

I'd be surprised by a mash pH of 5 to 5.4 after 15 minutes with an all pale grainbill without salt and/or acid additions.

Calcium and alkalinity influence mash pH. Do you know what levels they are in your water?
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Re: How accurate are ph indicator strips?

Post by Top Cat » Thu Oct 08, 2020 11:00 pm

Eric wrote:
Thu Oct 08, 2020 10:20 pm
Top Cat wrote:
Thu Oct 08, 2020 1:03 pm
Hi all.
I’ve been using these things for a few years now, and over the last few brews I am doubting their accuracy.
My last water report claimed an average ph level of 7, sulphate 50ppm chloride 45ppm, measuring with the strips and comparing the colour to the chart it is more like 6.
When mashing, after about 15 minutes a reading is taken, which is normally between 5 and 5.4.
This is with charcoal filtered water. For 25 ltr of beer, I like to add calcium sulphate (10g) and calcium chloride (5g) but add it at sparge time as I’m not sure and don’t want the ph to drop any more below 5 if salts are added to the mash water.
I normally brew pale ales and bitters.

Does anyone have any advice on a decent meter I could purchase if the general opinions are I’m working with duff equipment.

Today I suspect few available pH strips are suitable for brewing purposes. A sutable pH meter is likely cheaper than a pack of usable strips.

pH of water is unimportant. Mine is usually 6.0 direct from the tap. Exposed to air, an hour later it can measure above 7. Heated and mixed with pale malt, whether the water be pH 6 or 7, the wort produced will be pH 6.0 or 6.1. Water from my eldest daughter's home is usually around pH 5. Kept in a sealed container, heated then used to mash pale malt, the wort then produced will be pH 5.9 to 6.0. Leave pH of untreated water to chemists, I'm sure they'll have lots of reasons for measuring it that brewers .

I'd be surprised by a mash pH of 5 to 5.4 after 15 minutes with an all pale grainbill without salt and/or acid additions.

Calcium and alkalinity influence mash pH. Do you know what levels they are in your water?
Thanks for posting Eric, to answer your question no, the water board report wasn’t much help a year ago, and reading previous posts it’s obvious chemically it varies, but by trial and error the sulphate and chloride additions I’ve made produce clean tasting beers. The efficiency of my mashing is between 75/80% so seems okay.
It appears I need something more accurate at measuring the ph during mashing and then making appropriate adjustments.

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orlando
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Re: How accurate are ph indicator strips?

Post by orlando » Fri Oct 09, 2020 7:16 am

Eric wrote:
Thu Oct 08, 2020 10:20 pm
Calcium and alkalinity influence mash pH. Do you know what levels they are in your water?
This is the important stuff. If you don't know this your treating without a map.
I am "The Little Red Brooster"

Fermenting: Riders On The Storm
Conditioning: He Ain't Heavy, He's My Brother (Wee Heavy) till December.
Drinking: Kings & Queens (Eldridge Pope Royal Oak clone), Gyle brewed Little Red Ruth(ster) & Red(Ruth)Rain 1867 recipe, From Russia With Love (RIS)

Up Next: Stout! In The Name Of Love, Elusive Butterfly
Planning: Autumn drinking Beer

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Eric
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Re: How accurate are ph indicator strips?

Post by Eric » Fri Oct 09, 2020 3:37 pm

Top Cat wrote:
Thu Oct 08, 2020 11:00 pm
Thanks for posting Eric, to answer your question no, the water board report wasn’t much help a year ago, and reading previous posts it’s obvious chemically it varies, but by trial and error the sulphate and chloride additions I’ve made produce clean tasting beers. The efficiency of my mashing is between 75/80% so seems okay.

It appears I need something more accurate at measuring the ph during mashing and then making appropriate adjustments.
I remember being at that stage, it took me several years to realise I was going in circles. Bottles of lactic acid from Boots, packets of gypsum from the local homebrew shop and very expensive packs of pH strips purchase via a pharmacist friend. (pH meters then were laboratory equipment and costly.) I remember the frustrations trying to make good pale beers and the ecstasy of drinking Dave Line's Guinness that my water made so well. It's a well trodden path, but not necessarily the shortest route. An efficient route is more frequently arranged after learning from where one starts.

In times past there was little worthwhile information for water treatment freely available, no internet of course. Now, this a popular hobby, lots of advice exists in print and digital format. Sadly much conflicts and some is biased beyond reason. I'm not sure breaking through the water treatment barrier is any easier today and further, the importance placed on mash pH to the exclusion of other equally influential aspects of brewing can be a significant problem too.

Find out what you can about your water, getting a sample analysed simplifies this and if you do, keep another sample taken when you do.

Buy a cheap TDS meter. It will measure how much current a water sample will conduct between probes. Pure water doesn't conduct electricity, but minerals dissolved in water make it conductive. The more minerals, the better it conducts and the more Total Dissolved Solids it contains. Knowing what a particular sample of your water contained it is potentially possible to estimate what it contains when obtaining a different reading with a TDS meter to that of the sample analysed.

If your water has an excess of alkalinity, get a Salifert kit to measure it. From this and with acid like CRS, the alkalinity of your water supply can be reduced to balance with the acidity of grains in a mash, so getting pH within the accepted range.

Assuming you are not brewing a low mineral beer to be lagered for the better part of a year, add calcium salts to your liquor to a minimum of 100 ppm (max ~200+ppm). Most calcium from mash liquor will deposit with phosphate from the malt and diminish buffering, as also will that in the sparge liquor. Calcium in the boil enables break material formation and deposits with break and further phosphates, all in turn reducing buffering and lowering pH.

Do this and when you come to measure pH it should be in the right region, all the way from first runnings to finished beer. 15 minutes into the mash is really only a rough guide.
Without patience, life becomes difficult and the sooner it's finished, the better.

Top Cat
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Re: How accurate are ph indicator strips?

Post by Top Cat » Fri Oct 09, 2020 7:05 pm

Eric wrote:
Fri Oct 09, 2020 3:37 pm
Top Cat wrote:
Thu Oct 08, 2020 11:00 pm
Thanks for posting Eric, to answer your question no, the water board report wasn’t much help a year ago, and reading previous posts it’s obvious chemically it varies, but by trial and error the sulphate and chloride additions I’ve made produce clean tasting beers. The efficiency of my mashing is between 75/80% so seems okay.

It appears I need something more accurate at measuring the ph during mashing and then making appropriate adjustments.
I remember being at that stage, it took me several years to realise I was going in circles. Bottles of lactic acid from Boots, packets of gypsum from the local homebrew shop and very expensive packs of pH strips purchase via a pharmacist friend. (pH meters then were laboratory equipment and costly.) I remember the frustrations trying to make good pale beers and the ecstasy of drinking Dave Line's Guinness that my water made so well. It's a well trodden path, but not necessarily the shortest route. An efficient route is more frequently arranged after learning from where one starts.

In times past there was little worthwhile information for water treatment freely available, no internet of course. Now, this a popular hobby, lots of advice exists in print and digital format. Sadly much conflicts and some is biased beyond reason. I'm not sure breaking through the water treatment barrier is any easier today and further, the importance placed on mash pH to the exclusion of other equally influential aspects of brewing can be a significant problem too.

Find out what you can about your water, getting a sample analysed simplifies this and if you do, keep another sample taken when you do.

Buy a cheap TDS meter. It will measure how much current a water sample will conduct between probes. Pure water doesn't conduct electricity, but minerals dissolved in water make it conductive. The more minerals, the better it conducts and the more Total Dissolved Solids it contains. Knowing what a particular sample of your water contained it is potentially possible to estimate what it contains when obtaining a different reading with a TDS meter to that of the sample analysed.

If your water has an excess of alkalinity, get a Salifert kit to measure it. From this and with acid like CRS, the alkalinity of your water supply can be reduced to balance with the acidity of grains in a mash, so getting pH within the accepted range.

Assuming you are not brewing a low mineral beer to be lagered for the better part of a year, add calcium salts to your liquor to a minimum of 100 ppm (max ~200+ppm). Most calcium from mash liquor will deposit with phosphate from the malt and diminish buffering, as also will that in the sparge liquor. Calcium in the boil enables break material formation and deposits with break and further phosphates, all in turn reducing buffering and lowering pH.

Do this and when you come to measure pH it should be in the right region, all the way from first runnings to finished beer. 15 minutes into the mash is really only a rough guide.
Once again, thank you Eric, this last post is very informative, for me, has been put in simple English too!

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Re: How accurate are ph indicator strips?

Post by Carnot » Wed Oct 14, 2020 10:20 pm

Quick answer. Not very accurate especially if the sample is coloured.

Be very careful with pH meters. A pH determination is really only applicable in aqueous solutions- that means water. Once you have significant organic material the result is not necessarily accurate. The killer for pH probes is the storage. Never, EVER use distilled water. A pH probe should be istored mmersed in a KCl solution of 3-4 molar strength. pH measurement is highly influenced by the ionic strength. Low onic strength (distiled and RO water) can lead to pH determiations wandering. Ther are many good websites on pH probe mainenance- sadly the best one is now defunct.

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Re: How accurate are ph indicator strips?

Post by Top Cat » Thu Oct 15, 2020 9:14 pm

Hi guys.
I think my original question has been answered to great extent.
I’ve sent a water sample to Phoenix analytical for a comprehensive check, so I’ll know what I’m working with to make adjustments in future.

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Eric
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Re: How accurate are ph indicator strips?

Post by Eric » Thu Oct 15, 2020 10:39 pm

Top Cat wrote:
Thu Oct 15, 2020 9:14 pm
Hi guys.
I think my original question has been answered to great extent.
I’ve sent a water sample to Phoenix analytical for a comprehensive check, so I’ll know what I’m working with to make adjustments in future.
A very good step. Please post the findings of the analysis to open this discusion further.
Without patience, life becomes difficult and the sooner it's finished, the better.

Top Cat
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Re: How accurate are ph indicator strips?

Post by Top Cat » Fri Oct 16, 2020 7:33 pm

Eric wrote:
Thu Oct 15, 2020 10:39 pm
Top Cat wrote:
Thu Oct 15, 2020 9:14 pm
Hi guys.
I think my original question has been answered to great extent.
I’ve sent a water sample to Phoenix analytical for a comprehensive check, so I’ll know what I’m working with to make adjustments in future.
A very good step. Please post the findings of the analysis to open this discusion further.
Will do, as I’ll need help to use the results!!!

Top Cat
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Posts: 76
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Re: How accurate are ph indicator strips?

Post by Top Cat » Sat Oct 24, 2020 5:39 pm

Top Cat wrote:
Fri Oct 16, 2020 7:33 pm
Eric wrote:
Thu Oct 15, 2020 10:39 pm
Top Cat wrote:
Thu Oct 15, 2020 9:14 pm
Hi guys.
I think my original question has been answered to great extent.
I’ve sent a water sample to Phoenix analytical for a comprehensive check, so I’ll know what I’m working with to make adjustments in future.
A very good step. Please post the findings of the analysis to open this discusion further.
Will do, as I’ll need help to use the results!!!
Hi guys.
Please find results of water analysis below

Sodium as Na, mg/L 32.0
Potassium as K, mg/L 4.0
Magnesium as Mg, mg/L 7.8
Calcium as Ca, mg/L 51.8
Chloride as Cl, mg/L 51.9
Nitrate as NO3, mg/L 16.4
Phosphate as PO4, mg/L 4.5
Sulphate as SO4, mg/L 34.6
Total alkalinity as CaCO3, mg/L 92
pH 7.22
Conductivity uScm-1@20c 411

For my next brew I intend to try Dennis Kings Galaxy Delight, a strong well hopped pale ale, that uses malts and yeast I’ve never tried before.
I’d like to ask for your help on adjusting 36 ltrs of water for this particular beer.
Another question I’d like to ask although I suppose it should be on a separate topic, is the recipe requires dry leaf hopping 40 grams. Anyone know roughly how much weight I need to just get the hop bag to submerge? I usually use pellets and let them fall to the bottom of the fermentation vessel.
With a little luck Dennis might read this post!!!

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orlando
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Re: How accurate are ph indicator strips?

Post by orlando » Sun Oct 25, 2020 8:18 am

Click on JBK links, top left, 5th topic down, water treatment. Review that first
I am "The Little Red Brooster"

Fermenting: Riders On The Storm
Conditioning: He Ain't Heavy, He's My Brother (Wee Heavy) till December.
Drinking: Kings & Queens (Eldridge Pope Royal Oak clone), Gyle brewed Little Red Ruth(ster) & Red(Ruth)Rain 1867 recipe, From Russia With Love (RIS)

Up Next: Stout! In The Name Of Love, Elusive Butterfly
Planning: Autumn drinking Beer

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