Mash pH consistently low! Help!

[BrewBoyJoe]

I live in Harrow London and the published carbonate alkalinity value is 250mg/litre calcium carbonate. After consistently measuring too low pH at the start of the mash I decided to test the alkalinity with a Salifert test kit. I did this tonight! The value is 225 mg/litre which isn't miles away from the published value.

The pH strips I bought are from the homebrew shop! Potentially these are inaccurate! Does anyone have suggestions on the good strips, or otherwise some general advice. Oh, also I tried boiling as treatment and this also led to too low reading at start of the mash!

Also I appreciate the pH will drop throughout the mash, so at what point would you take the first reading? 5 mins in?

pH has been 4.7 to 4.9 or so

Cheers

Joe

[Twistedfinger]

Mine can be down to 4.2 (using strips) if I don't bother with water adjustments. I don't really worry about it as the beer is always great, I suppose it could be better and perhaps I should do a trial, one for the to do list..

[Bobba]

Have u tried CRS (carbonate reduction solution). Something like 1mL per litre of liquor should do the trick for putting it in the 5.3 region

[Dave S]

I'm new to water treatment, previously only adding gypsum/epsom salts to pale ales. The mash pH was always high - 5.6-5.7 and there was often a sharpness to the taste. I am just about to keg a Draught Bass clone which has had CRS treatment applied to the liquor. The mash pH was between 5.1 and 5.3 and the taste is great. So at this point I would say don't leave home without CRS.

[BrewBoyJoe]

Yes, I use CRS at 1.14ml per litre. I have also tried the boiling method instead. I plan to Burtonise the water to mirror Fuller's water for my Wild River clone on Sat morning! This is what they do apparently! Something must be wrong here! As far as I can see the sticks are the anomalous reading because the Salifert alkalinity test results are approximate to the published value, and my gypsum and Epsom salts have been added according to Graham's suggestions.

The beer does taste good, and my mash efficiency is pretty good for the set up! Just an impression, I havent calculated it properly yet! For now I will ignore the sticks results but it still bothers me grrrr

[Dave S]

Yes, I use CRS at 1.14ml per litre. I have also tried the boiling method instead. I plan to Burtonise the water to mirror Fuller's water for my Wild River clone on Sat morning! This is what they do apparently! Something must be wrong here! As far as I can see the sticks are the anomalous reading because the Salifert alkalinity test results are approximate to the published value, and my gypsum and Epsom salts have been added according to Graham's suggestions.

The beer does taste good, and my mash efficiency is pretty good for the set up! Just an impression, I havent calculated it properly yet! For now I will ignore the sticks results but it still bothers me grrrr

Have you tried different strips? I don't like using them, as I find there is always a bit of subjectivity in reading. I went for a cheap electronic pH meter from Amazon - £12.99 I think. It's obviously not the greatest at that price, but I find it miles better than the paper strips. I've spotted one, also on Amazon that has a 0.01 resolution and an error of +/- 0.07 for £34. Might go for that next.

In fact I've just seen it advertised at the top of this page - Voltcraft PH-100ATC

[BrewBoyJoe]

ok good to know. I may consider this for future. It looks like technology has moved on. In the past the received wisdom was always, don't buy a pH meter because their expensive and not that accurate (with the lower priced ones), and you have to faff around calibrating prior to every use. From the look of it this may no longer be true, at least the expense thing!

Still, I have to wait a bit before my next brew equipment purchase. The next thing will probably be a wort chiller as my add hoc contraction takes 1.5 hours to cool 30 litres!

In the meantime I need a recommendation on a reliable brand of papers! Failing that I'll just pay my money and take my chance!

Cheers

Joe

[Dr. Dextrin]

I have alkalinity in the range 230 to 270ppm, depending on time of year. I went through all the water treatment calculations (always using a Salifert test) and always ended up getting a slightly low mash pH, normally around 4.9, but I stuck with this because the beer still tastes fine. However, I did try progressively reducing the CRS I used, down to 75% of the calculated amount. Surprisingly, this had very little effect on the mash pH. I've tried several brands of pH papers and they all seem to agree - as well as you can tell from a colour change, anyway.

However, just recently, I've discovered that if I brew without any roasted grains (e.g. no 130 EBC crystal, which I use in almost all my brews), then the mash pH comes out right at 5.2!

So now I suspect that the water treatment calculations for a "bitter" are probably based on a bitter composed of just pale malt and that even just using normal levels of crystal malt can reduce the mash pH below the ideal. Of course, I knew that roasted grains reduce the pH, as I omit all water treatment when brewing porters and stouts and then the mash pH comes out right. I was just a bit surprised at how much effect more lightly roasted grains can have and I haven't yet figured out how to compensate with the water treatment.

[Dave S]

I have alkalinity in the range 230 to 270ppm, depending on time of year. I went through all the water treatment calculations (always using a Salifert test) and always ended up getting a slightly low mash pH, normally around 4.9, but I stuck with this because the beer still tastes fine. However, I did try progressively reducing the CRS I used, down to 75% of the calculated amount. Surprisingly, this had very little effect on the mash pH. I've tried several brands of pH papers and they all seem to agree - as well as you can tell from a colour change, anyway.

However, just recently, I've discovered that if I brew without any roasted grains (e.g. no 130 EBC crystal, which I use in almost all my brews), then the mash pH comes out right at 5.2!

So now I suspect that the water treatment calculations for a "bitter" are probably based on a bitter composed of just pale malt and that even just using normal levels of crystal malt can reduce the mash pH below the ideal. Of course, I knew that roasted grains reduce the pH, as I omit all water treatment when brewing porters and stouts and then the mash pH comes out right. I was just a bit surprised at how much effect more lightly roasted grains can have and I haven't yet figured out how to compensate with the water treatment.

Interesting, I use crystal quite a lot too, but my current brew, (first one using water treatment) used 250 gm of crystal gave a mash pH of about 5.1 initially, rising to 5.2, 5.3 ish after leaving the probe in the sample for a while

[BrewBoyJoe]

Interesting point about the Crystal. Perhaps that could have added to the situation in the past. However, at the moment I'm trying to make a hop bomb with pale maris otter and no speciality grains at all. Previous beers of this type have come out at 4.9 ish or lower according to my sticks which are from the homebrewshop and by no means the cheapest! Maybe I should believe them! I could try using 75% CRS next time and see what that does! In anycase I don't think this would ruin my beer! I haven't got time to buy anymore sticks as brewday is on Sat!

[mabrungard]

I have found that paper pH strips are completely unreliable for use in brewing liquor. An acceptable alternative is to use plastic pH strips from ColorpHast. These are reliable strips, but even the manufacturer reports that they have a slight reporting error in wort. You can read more about that issue at the link below. Fortunately, it is a relatively consistent shift of about 0.2 to 0.3 units low.

http://www.homebrewersassociation.org/f ... ic=13764.0

pH meters are certainly a chore if you don't want to be bothered with something else in your brew day. I find that a good meter that is properly cared for and calibrated is much more reassuring than strips, but I'm an engineer. To each, his own. I do find that once you've figured out your brewing water treatment regimen, you probably won't need strips or a meter in many cases. Its when you try out a new recipe or your water changes that having those tools available is helpful.

Another thing that helps avoid testing is to use a brewing chemistry calculator that includes the effect of the various malts in the grist to estimate the mash pH. This has proven to be very helpful in getting brewers in range. As pointed out above, some malts are more acidic than others. Those changes to a brewers grist mean that changes to their liquor are also needed. Bru'n Water software is an example of a brewing chemistry calculator. I note that there is a link on this forum to a mineral addition calculator, but it doesn't provide guidance as to how that proposed liquor is going to wort with the proposed grist. There is no way that a alkalinity or residual alkalinity value can be recommended for a particular mash without that grist information.

I notice that someone said that mash pH drops during the mash. This is not my experience. Mash pH stabilizes relatively soon after doughing in and it climbs by about 0.1 unit during the course of a typical mash.

In closing, do get better pH strips if you aren't willing to endure the cost and hassle of getting a meter. And do check out Bru'n Water software, it will get you much closer with your brewing liquor adjustments than blindly following a recommended water profile. If you have your tap water information, you are ready to use Bru'n Water.

Enjoy!

[Jim]

Just saw this thread.

Re the original post, surely high alkalinity of the water will result in high mash pH, not low. And CRS is used to bring mash alkalinity down, not up.

I suspect the pH strips - are you cooling the sample of wort before taking the reading?

[BrewBoyJoe]

Thanks Jim. Yes, I appreciate all that. I found out my sticks are duds! For whatever reason they're inaccurate. Although mash pH is still often read as quite low even with the new sticks, and doesn't quite tie in with alkalinity readings from my Salifert kit!, the efficiency I'm getting is ok and the beer tastes good, so that's the main thing! For future, I may buy one of those 5.2 buffers!