Mixing three waters

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
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#1: Post by welone »

First off, thanks to Pat Moore for covering the publication of the new SCA water handbook.
homeburrero wrote:Since around December 2016, we've been unable to get a copy of the SCAE water chart without buying an SCA membership. And the SCA provided no way to just buy the report outright.
I think that may have just changed - starting today you can buy a new SCA water handbook: https://store.sca.coffee/collections/bo ... 9334327398
And secondly, as a more useful thanks and simply because home-barista is IMO the best place for it, I'd like to share a bonus to the handbook in the form of an excel file to calculate mixtures of three different waters.
Using three very different waters in terms of alkalinity and total hardness a simple but lengthy calculation can provide the respectice percentages of any mixture for a set of a target values for both total hardnss and alkalinity. Of course, the target values are limited by the choice of input waters - or visually speaking they have to have a composition lying in between the triangle that spans between the compositions of the three chosen input waters:

The excel sheet can be downloaded for free here and contains additional instructions. One caveat seems to be though, that contrary to europe, bottled waters I saw in the US did not specify the exact chemical composition of the water - just the nutritional values, where the only useful info is the calcium content in recommended % daily intake... Though for some brands the info is available online.
Additionally, the excel file includes a conversion template to calculate the concentration of total hardness and alkalinity in ppm CaCO3, starting from straight mg/L as stated on bottled water labels or water reports.

I hope it proves useful to you all and would welcome any feedback

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#2: Post by homeburrero »

welone wrote: I hope it proves useful to you all and would welcome any feedback
Cool! Thanks Marco! Looks pretty handy to me, and fun that you get to see how your mixes look on the graph alongside the SCAE core zone.

I downloaded and played with it, starting with three waters: pure distilled, potassium bicarb concentrate, and Epsom salt concentrate, and then tried 4 targets that hit the recommended mixes favored by Robert Pavlis (recently departed HB member rpavlis, whose bicarb-only mixes are popular on this site) along with two corners of the SCAE core zone. Here's what I got:

The spreadsheet made it really easy to play around with these.

I ordered the new SCA Water Quality Handbook weeks ago, still looking forward to reading it. They evidently took all their copies to the Seattle Expo and have not yet got them back and ready to fulfill my order.
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welone (original poster)

#3: Post by welone (original poster) »

Hey Pat

Thanks - great that it was easy enough to use :)

Honestly for espresso I found that the differences must be quite large to taste a difference - for example that the alkalinity of the water has to be different by something in the order of 250 ppm CaCO3 in order to notice a difference. For drip on the other hand I found that differences of less than 40 ppm CaCO3 in alkalinity can be tasted by the majority of people (in workshops). Though comparing a "common speciality espresso" at a brew ratio of 2 (20g to 40g out) to a drip with brew ratio of about 15 (60 g per litre of brew water equaling about 880g of beverage), the filter coffee preparation has more than 7times more water per ground coffee than espresso.. So to get the same amount of buffering effect as the heritage scaa standard of 40 ppm CaCO3 in alkanlinity for drip preparation, in espresso almost 300 ppm CaCO3 in alkalinity would be the analogous amount!

Then I hope you'll get your copy of the handbook soon ,)