I've tried Chromatic's "Radio" offerings before without a lot of luck. Partly, due to not having sophisticated enough grinder and espresso machine, and largely out of not quite knowing what to do with them. These days, I have a very good grinder and a very good espresso machine.

I also did some reading of the Chromatic Coffee blog on the "Radio" coffee line.

•Very light, very rapid roast.

•Pull it with a quite hot espresso machine.

•Use incredibly soft water.

This is all a bit different, especially that last part. According the blog, they're pulling it with water at about 20ppm. That's near distilled, and pretty much what a home-grade RO system puts out.

Since I happen to have a RO system, and a Linea Mini which can easily dial in whatever temperature I want, and a pretty dang awesome Monolith conical grinder, I revisited.

I think these guys are onto something. As opposed to "on something".

http://www.chromaticcoffee.com/blog/quick-qa-on-radio/

http://www.chromaticcoffee.com/blog/wat ... -approach/

So I bought a bag of the Radio Ethiopia Konga. I purged the Linea Mini with RO water with just a splash of my usual Crystal Geyser water to just lightly mineralize it. I set the thumbwheel brew temp dial to 204f degrees. I ground, I dialed and I tasted.

Sure enough with a little adjusting, I pulled a very, very fruity and sweet espresso. An unusually fruity, mango and berry tasting and smelling espresso. All at temperatures and water mineralization levels which would pull nothing but thin and bitter sink-fillers from every other coffee I can think of.

Man, this stuff is much lighter in roast. So much so that it even looks completely different in the knock-box.

Interesting concept.

Very light roasted at 20ppm? I wouldn't have thought you could extract enough of anything to taste like coffee with those parameters.That's very interesting. I wonder what took them there in the first place.

I would guess a very light roast with its denser than usual bean would extract solids at a much slower rate. A higher temperature and the low water hardness would make the extraction much more aggressive pulling out the desirable solids. I would guess a normal (120ppm) hardness at a lower temperature would get you a sour bland cup. Wonder what would happen if you ramp up the extraction pressure to say 10-11 bar.

I can't find the post, but I wrote about this coffee, here a while back. It's very interesting. I've had it at the cafe and was stunned how good it was. And I'm not known for gushing praise at them in general. I brought a bag home and blew thru it very quickly. Luckily my water is quite soft. I had to order a second bag rather quickly.

If I find it, I'll post it here.

It's *sooo* fruity that I'm still deciding whether I like it. That's a weird thing to say, but it is so different that it is at once, stimulating to taste and a little out there. Definitely extremely unique and honestly, if I pulled any other coffee with these settings and essentially un-mineralized water, i'd get nothing but a very nasty sink shot.

I was extremely pleased with what I was getting off the Leva, but it occurs to me that it would be pretty easy to nail with a simple manual lever ran hot and distilled water or a very light mix of low mineral content water and distilled.

I've got all the Intelligensia Geshas coming shortly, but maybe I need to hit up Chromatic again. I know how much darn work their roastmaster put into nailing this whole endeavor. It's by no means a happy accident.

Just for grins, I tried the Decaf Ethiopia Sidama (also from Chromatic) with the same preparation method. I hadn't been able to pull it as espresso well before. But it was good as a poor over. Roast is pretty light, but not as light as the Radio coffee.

It came out pretty well with the same brewing conditions. I was surprised.

This is very interesting. The only potential downside is we have yet another variable to tinker with! And, as Tom says, it would easier to have a second machine, perhaps a lever, where we can use low mineral water for experimentation. Keeping our other machine for more conventional PPM water.

I posted this a while back about macthing your home water to a roaster's water to get the best results. I suspected it was why some coffees wouldn't work for people at home, no matter how hard they tried:
Another water question: Matching your water to a roaster's water for perfection?

Water composition tweaking is potentially great for the pursuit of coffee excellence. These days, the possibilities have exploded for espresso hounds. The myriad variables are now within our control. We have pressure profiling, flow profiling, grinder RPM profiling, preinfusion profiling, water temperature profiling, basket temperature profiling, extraction time profiling, roast profiling, and now water composition profiling. I'm probably forgetting some others.

Bottom line is the boundaries are being pushed like never before. And the coffee can only get better.

The only worry is that there are now so many possible ways to get from A to B in espresso, that our heads spin from all the variables we can control.

It sounds like this coffee is going to show up on my "to order" list.

Going with the "easy to nail with a small manual lever" theme, it might be fun to fill up a couple Creminas / Pavonis / etc side by side with the only difference being the water composition and play with the extractions of some of these coffees.