Juliet Coffee Water System
The Juliet Coffee Water System (JCWS) is an insanely over-engineered water treatment skid for specialty coffee.
Many other excellent (and MUCH cheaper/easier to use) water treatment systems for cafes exist, from vendors like Bluewater Group to specific units like the ProFlav Formulator to prosumer units like the Caffewerks Connect Cube. You can also talk to the good folks at Coffee and Water Lab to get help deciding what you need.
In most cases, the above choices represent what you should buy as a coffee shop owner who wants excellent water for your shop.
However...for me, as a combination nerd, marketer, researcher, builder, and technology enthusiast, the advantage of having the world's most precise water dosing system in my very own shop is enough that I decided to build it, with all the attendant costs and difficulties.
The Core Idea
Take any municipal water source and clean it down to a "blank slate" (TDS < 10 ppm via reverse osmosis), then precisely dose minerals into the water stream to fully express the flavor of a given coffee.
The side benefit is the ability to make any water recipe on-the-fly no matter the end-use. Using the JCWS you can produce every possible permutation of water for coffee as well as drinking water, ice, water for matcha, water for rooibos, water for...whatever.
But doesn't the [insert your favorite water machine] already do that?
Nope. There is nothing I've found on the market that can precisely dose the exact minerals you want into your water the way this can. The closest thing out there that I've found is a custom ProFlav Formulator (built by the guy who basically invented water for coffee), but you have to buy their minerals and it's a proprietary mix. If you want to bump Mag Sulfate 3 ppm, it won't do that.
The general approach across the top tier of the market is "We'll give you a few options to choose from, but beyond that, ya can't dial in."
That, by the way, is probably what you should do as a cafe owner.
JWCS, in contrast, is water treatment taken to the depths of an unreasonable obsession. I highly recommend against you doing this for your cafe; there are much bigger bangs for your ~$15k.
Open Source Ethos
Oh yeah, one more thing before you immerse yourself in the rest of the site: Pretty much everything is open source. A custom water skid is hard enough to build that the odds of anyone doing their own and competing with me hover slightly above 4 Kelvin.
Physics is physics. Filters and membranes and pumps and controllers are well understood. Putting this all together precisely, accurately, and repeatably at scale is expensive and a pain in the ass to build, but it's not (and shouldn't be) a mystery.
With all that said...if you are bone-headed enough to want to build your own, this site should act as a guide for you.
I am not a licensed engineer, this is not a set of plans you should follow blindly. Dosing water with chemicals can be a hazard to humans. Do NOT throw a bunch of pipes 'n pumps together and hope for the best.
Philosophy
My goal here is to make something awesome using well-understood and known mechanisms with a heavy preference for older industrial components that would otherwise sit dusty in some warehouse and represent a value capture of (on average) 50% or more.
I don't always get that; much of the "brains" of the unit makes no sense to buy used on the secondary market. Same with pipes and fittings.
This isn't "re-purposing" because I'm a hippie, it's just a natural thoughtline that the majority of this system can be way overbuilt for a relatively low price, in the process generating something that doesn't exist in the coffee/cafe niche. Solving that puzzle is super fucking fun for me.
How to use this site
- System Specs — stable engineering requirements and component specifications
- Guides — practical wiring, commissioning, and build references
- Progress — where we are right now and what's next
- Water Recipes — reference mineral profiles from the coffee community
- Regulatory — San Diego County source documents we're designing against
- Field Notes - Blow by blow of the build, so you're under no illusion that this was easy or cheap.
Every page shows when it was last updated (bottom of page). The site rebuilds and redeploys automatically every time the underlying docs are pushed to GitHub, so what you're reading is the latest version (although it may not be correct).