Chris' Coffee says: Don't descale! - Page 6

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
brianl

#51: Post by brianl »

JohnB. wrote:As Brian mentioned the alkalinity level isn't changed by the salt based softener one way or the other. It doesn't matter how much hard water you add back in your readings will stay the same, only the hardness level (& taste) will change.
I do wonder if your taste would change if you went from 40 hardness to 90 as much as going from 0 to 40.

I think the upper limit is 90-100 ppm and you won't taste anything above that.

User avatar
JohnB.
Supporter ♡

#52: Post by JohnB. »

brianl wrote:I do wonder if your taste would change if you went from 40 hardness to 90 as much as going from 0 to 40..
I do a similar "test" everyday as I drink the filtered water in the house & the straight well water (9grains) in my shop. The difference is minor compared to drinking fully soft water vs my well water.
LMWDP 267

Aida Battle: Indigo Reserve from world renowned Finca Kilimanjaro in El Salvador
Sponsored by Aida Battle
User avatar
another_jim
Team HB

#53: Post by another_jim »

Peppersass wrote:According the Jim's water FAQ, the alkalinity level is one of the determining factors in scale formation. So, 40 ppm might not be quite as safe as it might appear.
To recap:

Scaling is determined but the Langelier index, an equation that has hardness, alkalinity and pH as variables. You can replace actual pH by equilibrium pH, and replace equilibrium pH by a function of alkalinity. Once all the math is massaged, the effect of alkalinity on scale formation adds up to roughly double that of calcium hardness. However, the scaling potential is multiplicative, not additive, so removing either calcium hardness or alkalinity removes all the scaling. This is why cation softening works, despite leaving alkalinity unchanged.

In terms of corrosion prevention, alkalinity dominates, so cation softening is much safer for equipment than anion softening or complete demineralization, since very hard water, cation softened, will neither scale nor corrode. However, very hard, cation softened water makes for slightly dulled coffee. Given the fashion for overly bright espresso roasts, this may actually be a good thing. But it is unacceptable for high end regular brewing, and a compromise for properly balanced espresso blends.

In natural water, alkalinity is almost always less than calcium hardness, typically 66%. Mostly, you can take the TDS of the water and figure it's 60% calcium hardness and 40% alkalinity. If your titration measurements are far off this, you probably made a mistake, since if the water minerals are mostly magnesium and calcium carbonate, that is the proportions you will see by chemistry. The usual reason for mistakes is stupid unit tricks: TDS meters and ppm measures are in CaCO3 equivalents; if you use molarity or molecular weight, the German or chemist's unit of measure, the proportions are very different (alkalinity shows up much higher).

I suspect this discussion and some of the fear of scale may be shadowed by stupid unit tricks. The Chicago water I use is 150 ppm, 90 calcium and 60 alkalinity, measured in CaCO3 equivalence units. This is neutral water and optimal for coffee brewing (arguments about magnesium versus calcium aside). For me, it requires a flush descale of the steam boiler every two years or so with one cappa and three or four shot a day on average. A tear down descale would be required every ten years. There are some very hard water areas in the US, LA being the standout in terms of population. But a reverse osmosis water treatment with mixing that got to 150 ppm would achieve the same results in these areas; and be the simplest way to produce high quality water. The new cartridges with dual catalyst beds would work just as well, but it seems we still need a simple and fool proof way of adjusting them.
Jim Schulman

brianl

#54: Post by brianl »

another_jim wrote: I suspect this discussion and some of the fear of scale may be shadowed by stupid unit tricks. The Chicago water I use is 150 ppm, 90 calcium and 60 alkalinity, measured in CaCO3 equivalence units.
This caught my eye. Being in Chicago myself I've read the reports. Am I reading the alkalinity incorrectly or is it expressed differently when it comes to coffee?

http://www.cityofchicago.org/city/en/de ... lysis.html

User avatar
cannonfodder
Team HB

#55: Post by cannonfodder »

I just make coffee and descale once a year. Water hardness problem solved. Unless your water hardness is crazy high or super low, I dont see much of an issue. Now take my parents home with well water. If you add 2 more grains of hardness rocks will come out of the shower head. That needs a softener. First time I showered in a city with soft water I thought there was something wrong, the water felt different and tasted flat and bland.
Dave Stephens

User avatar
another_jim
Team HB

#56: Post by another_jim »

brianl wrote:This caught my eye. Being in Chicago myself I've read the reports. Am I reading the alkalinity incorrectly or is it expressed differently when it comes to coffee?

http://www.cityofchicago.org/city/en/de ... lysis.html
Interesting -- the raw lake (the most stable measure over the coarse of the seasons) Langelier index is -0.02, indicating a nearly neutral hardness/alkalinity around 90/60. The total TDS is also stated as 160, which is pretty compatible with that (and with my own measurements). But the hardness and alkalinity themselves are given as 150/120, which is not compatible with either the TDS reading or the Langelier index (150 + 120 = 270, not 160). Not really sure what they are doing. The measurements might be done from different samples; or they are normalizing the hardness and alkalinity up to a TDS equivalent (which is not what the unit data is saying)
Jim Schulman

brianl

#57: Post by brianl » replying to another_jim »

I was always confused by these reports and I'm glad to hear your explanation. It seems like the lake is neutral but at each of the plants, it appears to decrease the LI. Based on my knowledge, all of the water coming out of the plants should be scale free as they are all negative? Seems like either the KH and GH are incorrect or the LI is incorrect?

I only doctored my water because I assumed the hardness was that high. I will perform some API tests on my tap water to determine the KH and GH (I haven't checked the tap itself in awhile except for it's TDS being 150-160).

Flair Espresso: handcrafted espresso. cafe-quality shots, anytime, anywhere
Sponsored by Flair Espresso
User avatar
another_jim
Team HB

#58: Post by another_jim »

brianl wrote:Seems like either the KH and GH are incorrect or the LI is incorrect?
Yeah. I haven't done titration test for ages. But if the TDS is 150-160; how can the hardness be 160 and the alkalinity be 120? Barring some kind of unit change, or Wittgenstein math, it doesn't add up.

On the other hand, if the Chicago water board can't even do the sums; it's no wonder that people overestimate the scaling potential of their water.
Jim Schulman

User avatar
Peppersass
Supporter ❤

#59: Post by Peppersass »

another_jim wrote:Yeah. I haven't done titration test for ages. But if the TDS is 150-160; how can the hardness be 160 and the alkalinity be 120? Barring some kind of unit change, or Wittgenstein math, it doesn't add up.
My well water tends to vary a bit over time, but a typical measurement is 171 ppm hardness, 150 ppm alkalinity and 148 ppm TDS. I use Hach kits and the TDS meter that comes with the Zero Water product. The TDS meter could be off a little, but not by a factor of two.

I believe JohnB reported similar figures, and I think shadowfax told me his hardness and alkalinity didn't add up to the TDS (this was a while back, so it could have been a previous residence.)

I could have sworn I read somewhere that the TDS doesn't necessarily equal the sum of the hardness and alkalinity, but maybe I just dreamed that.

User avatar
Peppersass
Supporter ❤

#60: Post by Peppersass »

another_jim wrote:However, very hard, cation softened water makes for slightly dulled coffee.
Have blind taste tests been conducted using cation softened water from a wide variety of sources to confirm that? How do we know, for example, that the alkalinity level doesn't affect extraction?
another_jim wrote:Given the fashion for overly bright espresso roasts, this may actually be a good thing. But it is unacceptable for high end regular brewing, and a compromise for properly balanced espresso blends.
This is good for me, I guess. I drink mostly bright espresso roasts and I don't use cation water for brewing -- just my fairly hard tap water. I'm happy to periodically descale the Technivorm, and my vac pot doesn't need it.