Fear of Water

I was going to do revisit an old post about why someone’s coffee might taste bad, talking about the amount of dull burrs out there, as well as a bit more on cleaning and other stuff. However, one aspect alone deserved a post on its own. I will say right now that this is particularly relevant to water in London. It isn’t your friend.

If you live in London and want to know what you are up against then put your postcode in here. The news isn’t good. According to the website the water at the roastery is pretty bad. 284.7mg/l calcium carbonate. That is a lot, and our own testing confirms this at around 290mg/l and our Total Dissolved Solids (TDS) are up around 450-480mg/l. To give that some context this is a rough breakdown on hardness (from wikipedia – definitions may vary):

Soft: 0-60 mg/L
Moderately hard: 61-120 mg/L
Hard: 121-180 mg/L
Very hard: 181 mg/L

On this kind of scale this makes London water ridiculously evil! Compare it also to the SCAA published water recommendations that are found in this pdf.

Coffee Equipment

Water this hard is going to take your coffee machine down. It is going to cause failure incredibly quickly if it isn’t treated. Probes are going to get covered in scale, boilers will overfill, flow restrictors will clog up, heating elements will start to become less and less efficient, valves will start to have issues – the list goes on. It will be expensive to fix, regardless of whether you include lost sales in the financial damage.

I’d say 9 out of 10 machines issues (across all manufacturers) that I’ve seen in London in the last three years have been down to water. Which means that 9 out of 10 are preventable. If you are running commercial coffee equipment of any kind and not paying attention to your water treatment then there is expensive trouble ahead.

Single boiler/HX machines tend to suffer through bad water better than dual boilers. They can have their flow restrictors on the cold water side, which means that they are much less likely to scale up than flow restrictors inside/on the groups of brew boilers. However, there are still lots of parts that will suffer and impact overall performance.

The challenge with scale is that it is often out of sight (and out of mind), and therefore – if you aren’t paying attention to your water – then the only time you encounter it is when it reaches critical mass and something breaks. For those interested our water is at the roastery is approximately 68mg/l, with a TDS of around 140mg/l but we’re using an RO system.

If you own coffee equipment in a hard water area then you should be keeping an eye on your water. Test kits are cheap and easy to use. This isn’t the place to discuss how you ought to be treating water, as there are a variety of solutions for different needs. No excuse not to test though!

Brewing and hard water

Coffee brewed with very hard water isn’t very delicious. As a really simple exercise brew two press pots, one with very hard water and one with soft water with a TDS of around 150mg/l. Same grind, same brew temp, same steep time. The results are quite interesting. Hard water produces a chalkier, slightly heavier cup, that is completely and utterly boring. Soft water produces a far more delicious, complex and interesting cup with much better acidity. The difference is shocking to people, especially those who expect it to be subtle. These kind of issues aren’t limited to infusion brewing – espresso suffers as well. I should probably note that TDS is a massive factor here – very soft water with a high TDS isn’t going to make you great coffee.

So if your brew water at home is hard then there is good news and bad news:

Bad news: You really aren’t getting anything near the best out of the coffee you buy
Good news: If you’re already enjoying it then it could easily get ten times better just by using better water!

I haven’t delved very deep into water chemistry here – if you want something hardcore then perhaps check out Jim Schulman’s insanely long Water FAQ. This wasn’t really a long post about water chemistry and its effect on coffee, more a reminder to keep an eye on water quality as it has a massive impact on all aspects of brewing. A long post on water quality may be something for the future – if only as an incentive for me to understand it all better than I do now! If people want to add any corrections or clarifications to the above then that would be very welcome. I can’t help feeling a little worried that I’ve oversimplified here…

When it comes to home brewing then the choices are either to soften your water or purchase bottles of something suitable – which does feel a bit weird to recommend. I really must do a bunch of testing on Brita filters to find out what they are doing, and how well they are doing it! If anyone has any good info I’d be very interested to see it.

18 Comments

  1. A subject near and dear to my heart.
    In Canada, bottled water label requirements include a breakdown of disolved solids. Some bottled water is suitable, some is not. Last week I picked up a bottle of Evian (still) and some Esker. The Evian was over 500 in TDS, while the Esker was around 75. It also contained residual chlorine, as it is disinfected at the plant in much the same way as municiple water. The lesson being, don’t assume bottled water is suitable.

    There is a way to easily and practical way to have ideal water. You can purchase distilled or RO water and spring water in large jugs at water shops and most supermarkets. That makes it economical. If you have a TDS meter or test kit, you can mix these two sources to obtain water at a near to perfect hardness and TDS. Many espresso machine can draw water from a jug so this can be used as a short term solution for espresso bars as well.

  2. The requirements are the same in Europe – all bottled water displays a breakdown of its mineral (and other) contents.

    Distilled water is surprisingly hard to find in the UK, I had to use de-ionised water for calibrating my extract mojo….

  3. I’ve posted on this issue before – http://danielofarabica.com/miscellanea/theres-something-in-the-water – so it’s nice to see the subject addressed here. Thank yo for that.

    About a year ago my home water filter (a PŪR unit that mounts on the kitchen faucet) needed to have its filter replaced. I didn’t have any replacement filters handy so I was forced to use water straight from the tap for both drinking and making coffee. As I understand it, drinking water that has passed through an expired filter is worse than drinking unfiltered water. By worse, I mean that it is possible that the concentrations of the elements you were trying to remove could actually be higher through the expired filter than if you simply used the water coming from the tap such that, even if your water wasn’t dangerous to drink without a filter, it might be dangerous with one that is need of replacement. I wasn’t going to risk my health so I stopped using the filter until I purchased a replacement.

    I live in the San Francisco Bay Area, California. Oakland, to be exact. San Francisco is famous for the quality of its water and I am not aware of any issues with the water in Oakland or the greater East Bay, for that matter. For me the using the filter came down to caution and taste – just in case there were any issues I was unaware of, I could count on having some measure of protection at the faucet. And the taste? Well, I thought the water just tasted better. I could taste the difference. It was subtle but I could taste it.

    The thing is – and this where my water epiphany happened – my coffee tasted better without filtered water: fuller body, more flavorful, more complex than with filtered. The coffee I had been making with the water that was run through the PŪR tasted meek and bland in comparison. “How could this be?”, I thought.

    I have always been told that to brew a good cup of coffee you need to use filtered water. That directive has been in every home brewing how-to I have ever read and It tripped off the tongue of every barista and bean counter sales person I ever ran in to. Including my own own.

    But it’s not true.

    The truth of the matter seems to be – as the truth of any matter seems to be – is that it depends. It depends on the water you start out with.

    In the future, for those coffee roasters and bars that want to drive the consistency of their product into the home in a more thourough manner, it might be wise to bone up on the water quality of the areas that are served by your shop(s). To go even further, knowing the effects various brands of water filter are going to have on the water coming from a customers tap would be useful as well.

    In my experience, water quality seems to be right up there with water temperature and grind particle size consistency in its effect on coffee flavor.

  4. It would be interesting to know how your old filter worked. It is also important to distinguish filtration – which generally removes bad odour/flavour/chlorine/particles with softening and water treatment. All water should be filtered, but not necessarily softened in any way or treated further.

    Some anti scale filters add in things like polyphosphates, while others use ion exchage.

    If your base water quality is good – reasonable TDS and not too much hardness – then it should be fine for coffee without much doing to it.

  5. I was exactly wondering how to softened water, is their any softener available in store?
    I looked for Brita but it seems like it’s a more a filtration than a softener.

  6. James,
    If your interested in doing a bit of reading on the subject, you should check out “Water Processing: Residential, Commercial, Light-Industrial”. It is a textbook put out by the Water Quality Association, and it is full of useful information. The website to find it at is http://www.wqa.org/store/productdetails2.cfm?Product_ID=E18
    -Scott

  7. In Baltimore, we’re lucky in that our water is quite good for coffee. Very good I would say. About once a year, I run our water supply to a tester for analysis and the results have been uniform for the past six years, with only one parameter being off the “ideal” slightly.

    This is where my thought comes in. Do we really want uniform water worldwide? Do we want water that tastes exactly the same? And produces coffee that tastes the same? Are we trying to be like Coca-Cola?

    What I mean by this is that local differences in water should be celebrated and explored in coffee. Many people love to say that the difference in Parisian baguettes versus baguettes in their hometown or elsewhere is the water. That baguettes in Paris taste different (mostly better) because of the qualities in their water supply.

    True or not, I think it is an interesting proposition. Luckily, I have the opportunity to travel quite a bit. As such, I sometimes take an hour or two to visit local coffee shops in the areas. While I prefer “good” coffee, I’m concerned that much of the recent discussions seem to direct our niche towards uniformity. We talk about what is the “right” way to brew. The “right” parameters. The “right” readings. We talk about these things as though everyone should be required to conform. I think these are False Prophets.

    As I travel to the different coffeehouses, I want to taste diversity in the cup. I want to experience diversity in the nuances. I want my experiences to be different wherever I go. What I don’t want is to discover that the Ethiopia Amaro Gayo I tasted at Barefoot Coffee tastes exactly the same as the one I tasted at Volta in Gainesville and Caffe D’Bolla in Salt Lake City. That would be a disappointment because while the coffee would be “good” it would all be the same. At that point, they might as well unify their names under the same brand.

    Yes, I want and advocate “good” coffee, but I caution against this certain tide of “same” coffee that seems to arise when all of these conversations are viewed in whole.

  8. Jay,
    It is an interesting point you bring up. I have been curious about this goal or pursuit of the ‘perfect’ cup of coffee/ ‘god shot’ of espresso or you name it. I like to challenge peoples’ perceptions in order to gain insight into the important but perhaps subtle difference between ‘good’ ‘better’ and ‘preferred’. Have you had good coffee everywhere you have traveled? If so, were the coffees that you considered good even remotely similar in taste, extraction, presentation etc?

    I can try to make the point this way: I have 12 green coffees in stock at present. They are all good coffee. What does this mean? Well, to me it means they are well picked and processed with minimal or no defects in preparation (green), they have some aspect of originality that reflects the place they came from, and at a more practical level, they can be roasted and brewed to make a nice cup of coffee or espresso that someone close to me would want to drink.

    So, they are all good. But perhaps more importantly, they are all different. Otherwise, would there be any point in going to the trouble of sourcing and stocking so many?

    Back to the question of water: It seems that the published chart for water quality represent an ‘ideal’ in terms of quality, based on a certain brewing standard, the SCAA’s idea of ‘perfect’. I think it’s fair to say that rarely in real life would that ideal be met. But as James says in the post, the idea is to raise awareness that good water is needed to make good coffee. Perhaps not that water A is better than water B and makes the best cup of coffee. This is where the preferences and craftsmanship of the coffee grader, the roaster, the barista and customers come into play. At the end of the day, you decide what you like best, not what is best. To me, that is the beauty of specialty coffee.

  9. The purpose here wasn’t really to talk about perfect water, or homogenisation in coffee. There is a lot more to water than discussed here, and there are things that impact cup quality that aren’t really easy for us to control until we strip and selectively remineralise which I think is wasteful.

    I’m already talking myself off topic!

    Suggested guidelines are just that – the “ideal” has likely come about through various controlled testing and shouldn’t be taken as gospel.

    What should be taken as absolute fact is that hard water makes bad coffee and ruins equipment. Softening of water like this is important, and still allows you to have diversity.

  10. When tasting expensive coffees, I exclusively buy water from wells to sort out any arguments to which I can complain about it. It’s the first and last fact in great coffee.

  11. Mark-
    Have I had “good” coffee everywhere I’ve traveled? Hardly. In fact, good coffee is a rare experience – regardless of where in the world I happen to be, and that includes the Third Wave First World shops.

    And perhaps my thoughts pertain more to the 3W1W shops than anywhere else. Because it’s within this realm that I see the most argument about having everyone agree to some sort of acceptable standard for “good”, meaning: “right.”

    In spite of the fact that I might not prefer some of the methods, techniques and flavors I taste in the world, I’m not enthusiastic about defining this “World Standard” where every single water parameter and brew refractometer reading is the same. I’m not interested in that. I’m interested in the uniqueness of this shop over that shop. I’m interested in exploring the differences between coffees and the ways different places prepare those coffees. I want something tasty and not uniformity.

    I agree that an understanding and awareness of water needs to be present in the barista and coffee shop operators. Water is the major component of our product and it needs to be addressed. And while extreme water conditions can (and will) cause equipment and taste problems, I certainly am not an advocate for uniformity in water worldwide. For example: reverse osmosis treated water systems.

    It is why I mentioned the Baltimore water that I have been dealing with as both a manufacturer and a coffee retail operator for the past ten years. Our water is such that it does not cause serious degradation in our equipment and it is slightly off the “ideal” but the water tastes great and we use that to produce coffee that we think is lovely and are proud to offer to our guests.

    This is also not to say that Baltimore water is “better” than other waters. Again, I’m not very interested in that. I’m interested in enjoying different experiences when visiting coffee shops, and part of that difference is the water.

  12. It seems insane that anyone living in London would use anything other than bottled water when making coffee (or any beverage) if they expected it to taste nicely.

    London water is barely fit for bathing oneself let alone for consumption.

  13. Very interested in anything you come up with on the effect of water filters. I use a German product called Aqua Select, which I like because it’s refillable (unlike Brita). I think they’re all activated carbon-based anyway.

  14. Hi guys, i recently did testing of Brita jug filters versus a simple home RO system. The brita jugs contain a small amount of softening ion-exchange resin, and carbon. According to my tests, the brita jug works well on my water (which is already relatively good in terms of TDS) if you run water through at least twice. The RO filter i got did a much better job. You can read the full results on my blog if interested: http://www.brewmethod.com

  15. You bring up some interesting issues. In Portland, we have good-tasting water, but there is a lot of “turbidity” or suspended solids from the water they pipe in unfiltered directly from the mountain reservoirs. I’ve been wondering about the whole calibration of refractometers for coffee. It seems like you are really interested in the *differential* between what your water looks like before and after brewing. For that reason, it would make more sense to me to zero your refractometer using your *actual* brew water, rather than an “absolute” zero with distilled water. In other words, if you already have 150 mg/L of non-coffee TDS in your water starting out, that would seem to yield an ambiguous brix reading since you then measure the combined coffee and non-coffee dissolved solids, with no way to distinguish between the two. Only by removing the original water’s TDS could you determine the change made due to the introduction of the coffee .

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