I want to use this branch to discuss how we, as an industry, tackle the problems of water. Water effects our equipment, but it also massively influences how our coffee tastes - both in our cafes, and also in our customers homes.

We need a better solution than we have now.

In Belgium there are several brands available: Spa Reine (blue), Montille, Glaciar, Mont Roucous, Mont Calm.
Whenever a customer asks how to brew coffee X with device Y, a coffee shop will automatically grind the coffee to a certain particle size. If this customer has a grinder, a grind description/sample will be given.
Water should follow that same path. Either as a suggestion: use one of these brands of water. If the customer is up for it (3Q: good mood?, talkative? & interested? cfr Doug Zell, nbc2012) you can give him the guidelines on how to determine good quality water or even suggest a RO unit.
It's all part of the barista a) giving sound advice, b) explain why and c) being a soundboard for questions of customers

There are a lot of questions intertwined in "How do we fix water?" What are the variables?

First, the water itself:
1. Is it only TDS that affects taste? Does mineral composition matter?
2. How can we measure this in a home or commercial setting?
3. Assuming TDS is the main driver, is it simply a matter of reducing TDS, or is there a range best suited for different brewing methods? (Higher for press, medium pour over, low espresso?)

Secondly, what is state of the art?
4. What are the options to solve this problem? Reverse osmosis, charcoal filters, water softeners, bottled waters, spring/natural source waters? How do these affect the water, and to what extent?

Finally, a side note:
5. Are we optimizing for taste, or for machine longevity? I realize taste is the end point, but much of your post comes back to scale on a machine, not flavor of the final shot.

Break the big problem down into a set of smaller ones that can be answered or tested, where data can be gathered informally at least so we can move towards standards.

Water quality is important to sooo many industries, surely we can find something related? Beer springs to my mind, as it has a robust speciality sector... but the difference is that they do not need to prepare and serve the beverage at the same time. However, water quality information might be gleaned from that industry. I was talking about green bean drying in a cab on the way home from a wedding and the driver happened to be interested in Fava beans. Everything I was saying about coffee seemed to parallel what he knew about Fava beans.(I didn't ask why he knew so much about them) Maybe we can find some parallels in other industries and steal their good ideas.

Something more similar is tea. I don't know much about it, but I've always thought it was amazing that you could make money off of tea (low cost, several infusions...) and I'm sure there is much we could take from their enterprises ("wine-list" style menus, excellent intimate service, £5 price tags and higher). Does anyone know how they manage their water in a shop? Likely, it's the same as us. What I do know is that many home users use bottled water. I can't imagine why tea might be more sensitive to water than coffee is, yet I don't know of anyone that brews coffee at home with bottled water(as opposed to merely a filter). Considering we suggest that they weigh, temp, measure, and freshly grind with an excellent grinder... why not water?

We work closely with our equipment suppliers. Why haven't they given us something? You know why? We haven't even asked for it yet. We, as an industry, should know what we want, and then figure out how to get it. The Catch-22 being that we won't know what we want until we have it. However, this is just how we've always moved. Pressure profiling springs to mind. If we ask, they will build it. As for knowing what to ask for... we'll just have to really, really experiment and come together and figure out what is best. Bottled water vs filtered water cupping, anyone?

I'm not sure how much to go off about water in this forum but I wrote a piece about my day to day issues with water here: madisoncoffee.blogspot.com

I think the problem we face is two fold: What do we want? and How do we get it?

What are the chemical properties that we want in our brew water and what kind of system do we use to accomplish this?

I think we need a brew water chemistry that most importantly stays out of the way of the brewing variables that affect the cup: grind/dose/temp./pressure/brewform. Water chemistry should be designed so that these variables are what most affects the final brew. Should water be a variable we are trying neutralize or a variable we are trying to manipulate to change flavor. Right now I think I lean towards trying to neutralize the 'problem' of brew water so that we can best taste the impact that origin, grind, dose, water temp., water pressure and brew form have on the final flavor.

My name is Ryan, btw and I'm involved in the equipment service end of the industry...
In Madison, WI there is a company with an interesting Ion-exchange system that uses Carboxylic Acid as the trade-substance. It trades hydrogen atoms for carbonate which messes with pH, but is very effective in removing mineral. I've worked with them to bypass hard mains water back in to bring TDS to 150ppm and hardness back up to 5gpg and then run it all through a taste and odor filter. This also repairs the pH issue. So far I've been really happy with it, and it is a no-waste system compared to RO. I think educating people about the basic needs they have for water from both a coffee flavor and equipment performance perspective is super-important.

I think manufacturers have made strides on this topic. Synesso gives very specific allowances for water chemistry so that their equipment performs as it was designed too...

I'm currently providing my customers with free RO water if they bring their own container, but perhaps this has some potential:

lifesaversystems.com

I've contacted them to see what effect their filter has on TDS, but haven't heard back yet. Perhaps I'm completely off, but I'm sure it would do something good, bad, or interesting to the coffee!

To be honest, there is so much work to be done, and it's difficult work. My suggestion is this: Someone set up 3 similar machines with 3 different water types... all waters that are safe for espresso machines (low/zero LI). Have 3 different shops/roasters come in, dial in the same coffee. Taste. Then we all rotate and redial in. Repeat. Dial in is necessary because of differing extraction rates, different people will dial in differently, which will give us a bit more scope. Discuss, take notes, beers after, send the water to some lab. Considering how complex the issue is, I don't even know what factors we would start to isolate, but this sort of get-together might help us decide on that. It won't give us answers, but maybe direction.

I actually don't think "we" (the coffee industry) have underestimated water all that much. I've understood the basics of water quality since the mid 90s, and the very first modern Golden Cup recipients had to install RO units to achieve Golden Cup certification, which got lots of awarenes at the time. At one point, all Starbucks stores opened with RO systems installed. In the 2000s, another wave of interest in water quality struck, and lead to the development of the Water Quality Handbook (with exactly the kinds of taste experiments Jason describes, except with filter coffee not espresso) and the Water Quality Standard (already alluded to).I don't think it's appropriate to take our normal "we haven't done the research" tack on this one.

I do think we have a problem, though: RO tech (which is the viable solution at the moment) is wasteful and expensive. The first is being worked on (RO is also a tech used to desalinate water, a booming field right now). The second has to do with perception: a coffee shop or consumer won't blink at splashing out on a fancy espresso machine or pod machine or whatever, but an RO unit seems expensive. This mindset is what needs to be changed, and we need to support it. Here's where "we" (human beings) get over-skeptical and frankly cheap.