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Cork Water Profile

Started by mr hoppy, June 29, 2020, 06:03:32 pm

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mr hoppy

Following on from some conversations at our recent Zoom meet up and on Whatsapp I wanted to post this to explain how I came up with the water profile I use for brewing.

While Irish Water don't provide full details of water profiles the page below is a useful resource. It provides details of test results for some of the minerals brewers are interested.


Using this source I've come up with the following estimated water profile for Cork city.   

Sodium: 11
Chloride: 17
Sulphate: 22
PH: 8.1

Also, while there's a good number of test results they don't seem very up to date (at least for my address) as the last test results for the minerals we're interested in date by to 1 October 2019. Having said that there wasn't much variation in results for the minerals (+/- 2-3 ppm) so I reckon they are good enough for my purposes.

There was more variation in PH but I always test that any way, and I adjust my water with phosphoric acid before mashing so I'm not that concerned about that. Unfortunately the results don't include Calcium, Magnesium and Bicarbonate.

However, I was able to estimate these based on occasional testing over a number of years using the aquarium test kit linked below and the instructions on this page.


Aquarium test kit


Based on that I came up with

Calcium 19 - 22
Magnesium 5 - 6
Bicarbonate  37 - 65

The most variable parameter is Bicarbonate. But again, I'm not concerned about that as I'm knocking that out by treating with phospohoric acid.

Obviously YMMV, given that RO isn't an option without a system and that water adjustments don't need to be precise I've found these stats have worked for me.