70/30 Water - Page 2

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
User avatar
[creative nickname]

#11: Post by [creative nickname] »

Has anyone done a blinded comparison of 70/30 with 70/0 (in other words, just adding bicarbonate and leaving the magnesium out)? I ask because our resident chemistry professor, Robert Pavilis, has taught us that ground coffee contains large amounts of magnesium on its own, so that adding some to the water should have a minimal impact on the actual extraction. But if no one has done a blinded taste test, I might have to order some magnesium salts to see if I can taste any difference myself.
LMWDP #435

brianl

#12: Post by brianl »

I have not and think that would be a great comparison. It seems like there is a lot of variation by roast level. However, it seems like most people (or at least espresso blends) enjoy espresso these days from C+ to FC (sometimes FC+).

Espresso Vision: the perfect cup of coffee starts with understanding your roast
Sponsored by Espresso Vision
Rush

#13: Post by Rush »

This topic is very interesting to me. I am familiar with water chemistry, and have some experience "building" water from RO for brewing beer. I have been looking around for a while trying to find other's experience with building water for espresso, but this is as close to a real evaluation as I have seen. I am definitely looking forward to the book.

Here is my contribution so far, for what it is worth. (What you paid...) For my espresso setups, I normally use RO water with ~18-24 TDS in my espresso machines and then sprinkle a bit of 90% CaCO3 and 10% NaHCO3 ( that's a scientific measure) over top of the ground coffee before I tamp. This results in saturation of alkalinity (I think) and is a very creamy, but round and boring shot. It is very hard to get a reasonable amount sprinkled on the coffee, so it is almost surely overdone on the addition. But there is lots of crema! I did not want scaling in my tank and I figured with 20 TDS that I would not cause too much leaching. This process leaves me easily drinkable shots that lack flavor diversity and and brightness. Without adding the buffers using only the RO water, the shot is overly bright and totally lacks crema. It is like a harsh pour-over. Not good at all.

With my Londinium, I have just tried the 70/30 water after trying to flush the tank a few times. I have only pulled two shots so far, but the taste is the best I have gotten from the Londinium. The taste is balanced, and there was some crema without being overly muted in flavor. I am going to experiment some more, but this is a great start!

Anyone else doing any experimenting?

User avatar
endlesscycles

#14: Post by endlesscycles »

My tasting of 70/30 revealed an over-heavy bottom and shrill top with hollowed out middle as compared to my municipal water supply, which is ~40ppm mountain runoff. It's possible my roasting has been adapted to my water, but I've had even thicker, sweeter middles brewing 200miles east in the flatlands from well water. It's possible halving the salts in 70/30 might get me closer to what I like, but I haven't experimented further.
-Marshall Hance
Asheville, NC

User avatar
[creative nickname]

#15: Post by [creative nickname] »

Did you test the composition of the well water at all?

In my own experiments with Robert's system, I have gravitated towards a 50ppm potassium bicarbonate solution, and I found that higher carbonate levels tended to make the coffee taste too bottom-heavy. I'm still hoping to play with magnesium salts at some point and see what impact they have.
LMWDP #435

User avatar
yakster
Supporter ♡

#16: Post by yakster »

My read on this was that 70/30 water was less of a recommendation and more of a starting point: "70/30 water is proposed as a starting point for experimentation in controlled brewing."

From the 5 Senses instructions for 70/30 water: https://s3-ap-southeast-2.amazonaws.com ... recipe.pdf
-Chris

LMWDP # 272

User avatar
homeburrero
Team HB

#17: Post by homeburrero »

Rush wrote:Anyone else doing any experimenting?
If you haven't seen it already, check out the original topic that got this one going - Global Customized Water at home. You'll see BuckleyT experimenting and reporting on his results with the A-B additives from Global Customized Water. He also has a Londinium. His machine was equipped with that in-line in-tank combination filter that the Londinium folks sell, so maybe need to take that into consideration when interpreting his initial analysis of the water coming out of the boiler.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

Urnex: 100% dedicated focus on coffee and tea cleaning
Sponsored by Urnex
brianl

#18: Post by brianl »

I am around a 70/30 distilled to Chicago carbon filtered tap ;). This gives me a 50ppm with probably 45ppm of it being calcium/magnesium hardness. The rest whatever is in Chicago water, I think mostly sodium. After this I've been playing with adding potassium bicarb to reach either 90 or 100ppm hardness (which is around the 50ppm mentioned). I haven't noticed much of a difference and only do this last part so the alkalinity doesn't drop too much.
[creative nickname] wrote:Did you test the composition of the well water at all?

In my own experiments with Robert's system, I have gravitated towards a 50ppm potassium bicarbonate solution, and I found that higher carbonate levels tended to make the coffee taste too bottom-heavy. I'm still hoping to play with magnesium salts at some point and see what impact they have.
So is this adding only 50ppm potassium bicarb from distilled water?

User avatar
[creative nickname]

#19: Post by [creative nickname] »

Yes, it is distilled water plus enough concentrated potassium bicarb solution to reach about 50 ppm.
LMWDP #435