Tasting the Regional Waters of Scotland
Live from Buenos Aires: David Wondrich on Drink History in the Americas

Measuring the pH of Mineral Waters

As part of the Water Project I am attempting to deconstruct and reconstruct mineral water. One of the prime sources of information for reconstructing mineral waters is the blog Khymos.

As I was buying strange bags of minerals like magnesium and calcium off the internet (seriously my apartment is full of suspicious white powders) I also noticed a word of caution in the comments of the Kymos website. 

It’s important to remember that the hydroxide solutions are basic and undrinkable until they have been carbonated, so an uncarbonated solution should really be kept out of reach of children!

So I decided I had best not kill myself and figure out what the safe and typical range of pH is and how to test waters I would make. I purchased a pH meter on Amazon, which meant I had to buy a whole bunch of calibrating solutions as well. 

PH_Scale.svg
A pH scale with annotated examples of chemicals at each integer pH value. Author: Edward Stevens

As you may recall from science classes, pH ranges from 0 to 14, with 7 being neutral.

 

0-7 pH = acidic

7-14 = basic/alkaline  

For drinking water, most sources cite an approved range of 6.5 - 8.5 or 6-9.

Low pH water is corrosive and bad for your plumbing, potentially leeching out toxic metals. High pH water can form scale deposits on sinks and water heaters. But I'm not really dealing with plumbing in my experiments. 

So I calibrated my pH meter, bought a bunch of water, and did some testing. 

 

Water Tested pH published pH Total Dissolved Solids published TDS
Tap Water 9.0          42 ppm  
Mavea Filtered Tap Water 6.8   28  
Zero Water Filtered Tap Water     6.7   0  
Distilled Water 5.6   0  
Arrowhead Water             7.1   38  
Fiji Water 7.5  7.8 135  220
Smart Water 7.2   28  
Evian (label says 309 ppm) 7.4  7.18 292  309
VOSS 7.3  6 34  44

Icelandic Glacial
(label says "pH 8.4")

8.3  8.4 50  62
S. Pellegrino
label says "TDS 915"  
5.3  7.7 549  960
Perrier     5.5  5.46 330  475

 Observations and Conclusions

  • My tap water is really alkaline. I don't get it because there aren't many dissolved solids in it. Also oddly, the pH lowers over time. If I leave the water out it eventually goes down to pH 7.5 or so. I need to research this one.  
  • The accuracy of the pH meter seems to be about .2 to .3 
  • Pellegrino has a lot of minerals in it. The TDS meter isn't great when it comes to carbonated waters, but I'm surprised at how far off my reading is from their TDS statement. I measured it a few times, even. The pH for Pellegrino listed on Wikipedia is 7.7 but mine is 5.3, so that's also really weird. 

 So now I have a range of published and observed results, so I can start building my own waters in keeping with them. 

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The water project imageThe Water Project on Alcademics is research into water in spirits and in cocktails, from the streams that feed distilleries to the soda water that dilutes your highball.  For all posts in the project, visit the project index page

 

 

Comments

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Sylvan

Portland adjusts the pH of our drinking water upwards with NaOH to avoid leaching metals out of the plumbing. http://www.portlandoregon.gov/water/article/327648 I'd think SF would be doing something similar, which might help explain why your tap water is so alkaline.

Kevin Liu

Camper,

You are the man for doing this.

Alkalinity shouldn't be directly related to TDS - not sure what you meant by that comment?

pH of all these waters will likely lower over time as atmospheric CO2 dissolves into the water.

For the pellegrino, why not let it go flat and then measure the pH? To accelerate the process, charge with an N2O canister in an ISI and vent - that will help all the CO2 rapidly cavitate out.

Kevin

Camper English

Doesn't carbonation lower the pH, so letting pellegrino, etc not be a good measure of it? I suppose knowing what the pH is of it flat vs. carbonated would be interesting and useful when making my own, possibly to predict by how much water changes just from carbonating.

I think my confusion about higher pH relating to higher minerality is that the water quality reports say that high pH water leads to scale building on plumbing, which I was assuming was from higher mineral content...

Charissa

You should measure the ph level of Perrier when it's flat.. aand see if I makes. Big difference..

X

S. Pellegrino & Perrier... carbonation = carbon. Literally, an acid. I have no experience with this, but my guess would be that might have something to do with the acidic test result.

Stephen Castro

I agree to you man, i think there is something to do with the acidic test result. Maybe they need to do another test.
http://www.showeringcenter.com/best-ph-meters/

Timothy E. Hegadorn

Carbon is not an acid. It does form Carbonic acid, when dissolved in water, though.

Gary Patterson

Similarly,Lemon juiceItself is acidic,However it becomes Alkaline in the Body.

Bob

https://en.wikipedia.org/wiki/S.Pellegrino it's now much closer to your result at 5.6 pH

Jeffrey Kastin

The pH of carbonated water will vary with carbon dioxide concentration it produces acid when dissolved in water. pH will also vary with temperature.

Camper English

Makes sense, thanks!

Ozmotrader

pH of carbonated waters should be measured while they are still carbonated, since that is the state that they're generally consumed in.

Drew

In Australia the S. Pellegrino bottle says its TDS is 854mg/l at 180 degrees C. I measured it and could only see a fluctuating range (approx. 300 - 400 PPM at room temp.) on the TDS meter - perhaps because it was still carbonated. I will try it again when it's flat. I wonder why they note a PPM at 180 degrees?
I found the same Ph of 5.3.

Camper English

Wow, I didn't remember Pellegrino had such a high TDS. That number is confirmed on their water report linked below. 180C is steam rather than water, so that temperature is super confusing. I just sent them an inquiry on their contact form to ask the question and I'll let you know if I hear anything back!

https://www.nestle-watersna.com/asset-library/documents/sp_eng.pdf

David

Carbon is NOT an acid.
Carbon dioxide dissolved in water makes carbonic acid.

Dissolving a pencil I’m water doesn’t make it acidic. Adding CO2 does.

Tom Ossorya

It's dry residue at 180 deg.Not sure if this thread is still alive ,though.

R. Cavalier

S. Pellegrino TDS is expressed in “mg/L“ NOT ppm. Take a look at their footnote on WikiPedia and their bottle label. You are reporting misinformation.

R. Cavalier

https://www.epa.gov/rmp/toxic-endpoints-are-milligrams-liter-mg-l-equivalent-parts-million-ppm

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