Water for Coffee: The top 3 things our research revealed.

How does water chemistry affect the taste of coffee...and what can we do about it?

Dr Adam Carr from our Coffee Science & Education Centre teamed up with the University of New South Wales (UNSW) UNESCO Centre for Membrane Science and Technology to find out exactly how water quality affects the flavour of espresso. With Adam's background in water and analytical chemistry, and UNSW’s expertise in treating and engineering water quality, we now understand what needs to be controlled, and what doesn’t, in order to extract key flavours in espresso coffee.

__________________________

Links:

[alexlazaridisf.]

Thank you! I love that 7 miles is producing these great videos.

[AricWu-fesk]

Dear Dr. Adam Carr,

Why does the coffee taste less sour, more harmonious, and more mellow after I use alkaline water?

I enjoy this flavor and aroma!

Thank you for your sharing!!
It's fantastic!😆

[jamesberry]

Thanks Adam, I love hearing the scientific views of what is.
Reckon I'll save my money and keep using my water filter jug.
Just needs the filter replaced regularly.

[farhansyahikram]

Thank you for this wonderful knowledge! 🙌🤘

[ozzy]

Thanks for the amazing research Dr Carr!

I'm a barista in the Illawarra and the most recent water quality report from Sydney Water shows my tap water hardness is 37 mg/L (which is the same at ppm right?) and pH is between 7.6 and 8.1
I've got a few questions for water at home that I'd love to hear your feedback on.

- To my understanding, a Brita filter from woolies decreases water hardness. What's the best way to increase hardness at home? Or is it just best to use my tap water as it is? I'd love increasing the fruity boiz (Furnaeol) in the cup.
- Does 60ppm hardness and pH 7-8 work ideally for filter coffee, like a V60, as well?
- In your experience, what is the best temperature to set at the kettle for filter coffee? I've seen temperatures ranging from 89 C to 100 C. I personally haven't tasted a significant difference (compared to brew ratios and grind size), but I'd love hearing your thoughts on it.
Sorry for the lengthy questions!

Thanks!
Btw, the video and audio quality on the uploads are much appreciated :)

[shire]

Hello!

As a point of clarification, do you define water hardness as strictly total ppm Calcium and Magnesium?

I'll give you an example, I'm looking at a water quality report that reports water hardness in CaCO3 as 49 ppm.

Total Calcium and Magnesium are reported at much lower levels, roughly summed at 2 ppm.

Thanks!

[Cfriend]

When you get the right water formula it lights up the full circle of taste buds in your mouth

[meredith]

I'm stuck with rain water which has a pH of 6.6 so not ideal but I'm guessing remineralising is the only option.

[zdeneksimonik]

Thank you for posting this great video and useful info! What would you recommend in areas where drinking water does not taste very well. If I understand well, installing filter will probably remove the wanted minerals as well. Is there any solution to that? Is out there any filter which remove bad odors and leaves minerals? Thank you

[alexlazaridisf.]

Dear beloved coffee guru, I'm under the impression that when humidity is high coffee grounds absorb moisture, creating greater resistance, and therefore slowing the espresso extraction down. Low humidity should make the shot run faster. I'm wondering if I have this wrong. The other day humidity was in the 90s where I live. Today down to the mid 30s. Contrary to what I expected, the shot ran much slower today (low humidity) than the other day (high humidity). Have I got things backwards? Is it temperature that is influencing things? The high humidity day was cool, the low humidity day was very warm. Other factors, such as grind size remained the same. What am I missing?

[TheCoffeeField]

Super informative, what’s the difference between chloride and chlorine?

[NikiLivi]

Where I live in the south US also out in the country I don’t trust our water for 2 reasons. 1. They have been replacing our water lines for the last several years that were supposed to be replaced 20 years ago. We never know when our water will be stirred up having dirt in it or chemicals from where they’ve treated it. Sometimes it’s has a pink tint. At times I’ve washed my hair using an expensive conditioner for my hair because it’s color treated only to get out of the shower and have my hair feel like straw. 2. We are surrounded by soybean fields so I worry about pesticides & fertilizers getting into our water system. Therefore my family drinks primarily bottled water. We do hope to buy a Berkey water filtration system soon to do away with plastic single use bottles. I’m wondering if the water from the Berkey would be good for the machine and for good tasting expresso? If not, is there a brand of water I could buy that’s suitable?

[thisidea]

I got 2 questions. As i know calcium, sodium, magnesium, potasium don’t effect extraction but perception. @lance hedrick has a video on it since i am just a small home barista. But your experiment says it otherwise. Can you explain this bit more. Secondly well filters or osmos is too expensive and i have market water 7.4 ph with some data is missing and i have sodium magnesium etc as a solution. But i was hoping to create my own water by buying %100 distilled water and using baking soda, epsom. But since i suck at these any advice where to start or understand how much to put. Or is it even safe to drink :)

[impalist]

Hi Adam, thanks very much for an informative video.

I'm fortunate to live in an area where the water is naturally soft. In my case, the only real "negative" is the elevated levels of chloride in the water (~40 ppm), as well as the water's balance tending slightly towards acidic (pH 6-6.5). As a result, I'm concerned about potential corrosion in my machine (in the boilers, etc.)

Unfortunately, I cannot plumb my machine in and must rely on more portable forms of filtration. I also read that chloride cannot be easily filtered out by conventional, portable filter products - for example Brita Maxtra+, Brita AquaGusto, BWT Penguin, etc.).

Do you believe the above aforementioned will do the job just fine for the machine regardless, or do I need to go the distilled water/RO + re-mineralisation route?

Is the acidity level + 40 ppm of chloride even something to worry about over the long-term use in my machine in respect to corrosion?

Apologies for the mouthful! I got a new machine that I want to treat right from day one.

[DavidRBermudez]

Hello...I have a reverse osmosis filtering system at home. Tap water is not an option here. What would you suggest to improve it for the coffee? What would I need to add to the water or do?

[speedmaster]

I just tossed away a good coffee maker because of scaling damage that is beyond salvage despite the best maintenance and descaling treatment. I bought a new machine this time a small espresso/ cappuccino machine and absolutely loved it. Being tired of equipment degradation I started using distilled water. Am I missing out a lot in the flavor department with this change of water type?

[stephen]

For home use distilled water + Third Wave Water or similiar custom mix of powders = tasty coffee, simple.

[SurvivorStory]

Got some numbers from my water manager in my City. Hardness is 40mg/L or ppm. How do I get to the optimum 60 ppm? My ph is 8.79 ave, Ca ave is 32ppm and Mg is 8ppm. Now what?

[ClubbersGuideCanada]

For people running on well water? I have roughly 2, 000 TDS w/0 hardness after an ion exchange water softener and 200 TDS after a reverse osmosis system (PH 7.5). Unfortunately, the coffee tastes flat so not sure what you would recommend to improve the taste?

[mibber]

One other point, is that if you enjoy acidity in your coffee, alkaline water will definitely mute that aspect of it, making it taste less good.