Global Customized Water at home - Page 3

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

#21: Post by Gary S. »

Has anyone here used or considered using Global's formulator system at home?

BuckleyT (original poster)

#22: Post by BuckleyT (original poster) »

...To continue with the GCW@home report... We were delayed while waiting for pH probe calibration buffers to arrive.

The pH swings for ZW are likely due to no buffers being present in solution and small amounts of contaminant. The basic nature of GCW in the jug was surprising. Equally surprising was the change in TDS and pH once the GCW was put into the pourover holding tank. Perhaps the in-tank filter equlibrated with the water in some way.

The biggest surprise was the drop of temporary hardness (KH) through the espresso machine. This is where I get to display my ignorance. If the carbonate is 'boiled off', does that mean that calcium has to be scaling onto my heating element at the rate of (54-18) 36mg per liter? I hardly use the steam wand, so this just does not seem right. I tested this three times.
homeburrero wrote:The high pH as well as having GH and KH slightly on the high side of the target seems good to me. I'd rather descale occasionally than worry about corrosion.
Still, these figures suggestive of active limestone depositing onto the heating element are disconcerting. This would be one reason to replace a small amount of Ca salts with Mg salts, although all Mg salts are described as bitter, to varying degrees.


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BuckleyT (original poster)

#23: Post by BuckleyT (original poster) »

[Conversations with homeburrero and Cindy of Prosum Roasters]
Thanks, Pat, you make a good point. If the total hardness, GH, remains unchanged, then it is unlikely that limestone is plating out onto the heating element to any significant extent.
And thanks to you, Cindy. For all my meticulousness, I did not test the GCW on either side of the Bestcup-M in-tank resin filter, which the Londinium has. That ought to be good for one more post on this uninteresting thread (except to me) and then perhaps we will have really exhausted the subject.


BuckleyT (original poster)

#24: Post by BuckleyT (original poster) »

Update on Global Customized Water at Home

Below is a picture of the glass pyrex pitcher used to transfer the last of a gallon of GCW.

The white patches and film that you see is sediment from the jug of GCW.

The GCW is mixed according to directions in a glass jug. At this time a fine sediment is beginning to coat the bottom of the glass jug. There is no evaporation - the jug is kept sealed. The quality of the RO water and the GCW mixture is documented earlier in this post.

After rinsing and filling the jug with RO (no GCW), scratches can be seen in the sediment coating the bottom of the jug.

What's up with this!? I do not want this stuff in my boiler.

I posed this question to the supplier of Global Customized Water (Seattle Coffee Gear) and I am waiting to hear back from them.


BuckleyT (original poster)

#25: Post by BuckleyT (original poster) »

I heard back from Seattle Coffee Gear (SCG). Courtesy dictates that one does not publish an email without the consent of the author, so I will paraphrase their response.

They were quite cordial and sympathetic and suggested that I decrease the amount of Globalized Custom Water 'reagents' to the gallon of RO water, depending upon how this affected the taste of my coffee.

They provided this link, which does not work for me: ... -standard/
so, I went to and searched for "water quality standard", which gave me the article to read, but it had the exact URL address that did not work: ... -standard/
Go figure.

Anyway it was not ay new information for me, except to remind me that my home GCW deviated from the scaa's recommendations in calcium hardness [sic] and pH.

The SCG correspondent mistakenly told me that I had not measured calcium hardness. They did recommend that I contact Global Customized Water directly and kindly gave me the contact link. This link also did not work but it was not trouble to find the web site and the contact form.

Since I can publish my own email correspondence, this is what I just finished writing to GCW:

Dear Correspondent:
I am using ampules of GCW at home. I obtained the ampules from your distributor, Seattle Coffee Gear.
I am adding both ampules to a gallon of RO water according to your instructions.
The solution of GCW is throwing a fine sediment in the bottom of the gallon glass jug used for mixing. In addition, I am getting GH and pH values that are outside of the SCAA-recommended ranges.
My understanding is that your product is being used at SCAA events. My questions revolve about the issues of why am I getting sediment and water values outside the recommended ranges?
I have monitored TDS, GH, KH and pH of the RO, the RO in the glass jug without GCW, the glass jug after CGW has been added, the GCW mixture in the espresso machine holding tank and after it passes through the boiler.
I have a spreadsheet of the values and photos of the sediment.
I have insufficient knowledge of water chemistry to appreciate what is happening , but I am among those hundreds of coffee hobbyists who are keen to participate in current coffee technology.
I have been posting my experiences on Home-Barista and I would like to have some expert direction in the use of your product and some reassurance that I am not going to be clogging my in-tank Bestcup-M filter with sediment or depositing scale on my heating element.
Buckley T

We will wait for help.