Adding a bit of Calcium to RO/DI water?

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

#1: Post by Irishespresso »

I searched on this site quite a bit and really didn't find a good answer on this, maybe I'm doing something wrong but several search terms turned up 10+ pages of results, all of which were from maybe 8-9 actual threads. Anyways...

I just purchased an RO system for the house as my town's water has hardness in the 125ppm range. The report does not give any data other than total hardness, no insight on individual mineral concentrations. The one mineral they do list individually is sodium which is at about 90ppm. My understanding is that this is super high on Na and that my Rocket (oscar 90) pouch is only making it worse, so I've decided to just make my own water.

Several years back I used to build my own water for all grain beer brewing, so I already have all of the equipment I need, no issues with making it a touch more complicated than necessary. Is there any benefit to adding a small amount of calcium (via gypsum) for taste reasons or is just magnesium sufficient? Not talking about going crazy, just a small amount and again only for taste improvement. I don't mind descaling my machine yearly or so, just don't want to have enough scale to damage anything in between. I also have a calcium chloride solution I could use but I don't want to add any chloride unless its way below "safe" levels.

Thanks!

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Irishespresso (original poster)

#2: Post by Irishespresso (original poster) »

Shoot one other thing I wanted to ask about was a simple calculator for building water. I have a complicated excel based program I used to use for beer brewing water but it is more complicated than needed as it takes into account malt roast and all sorts of other things. I downloaded the file from espressoschool-dot-com but it looks like there are errors in some of the formulas as certain things don't change with different inputs.

Thanks again!

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homeburrero
Team HB

#3: Post by homeburrero »

Irishespresso wrote:Is there any benefit to adding a small amount of calcium (via gypsum) for taste reasons or is just magnesium sufficient? Not talking about going crazy, just a small amount and again only for taste improvement. I don't mind descaling my machine yearly or so, just don't want to have enough scale to damage anything in between. I also have a calcium chloride solution I could use but I don't want to add any chloride unless its way below "safe" levels.
You are smart to avoid the calcium chloride. It dissolves readily but unfortunately adds a chloride corrosion issue that you don't want in an espresso machine. Gypsum (calcium sulfate) avoids the chloride, but sulfate isn't a great idea either, and if you have both calcium and sulfate in your steam boiler that gets concentrated then you could end up with calcium sulfate 'scale'. Which is not nearly as easy to descale as calcium carbonate limescale. Calcium carbonate in small enough amounts can work but you have the issue of low solubility. Some people us it and use a soda spritzer to lower the pH and make it more soluble. I use it but in very small amounts so that I don't have precipitate or scale issues. (Some info here about my water: An all carbonate water recipe (cloudy concentrate, no sodastream) ). I can't say that it's worth the effort. In fact to my coffee preferences and aging taste buds I haven't concluded that my recipe is tastier than plain zero hardness 'rpavlis water', i.e. 100 mg/L potassium bicarbonate in distilled or otherwise purified water.

You also could use calcium citrate as a calcium source. That's what the Third Wave Water espresso formula uses. But most people who want hardness minerals in their brew water just stick with magnesium sulfate - usually Epsom salt, which is magnesium sulfate heptahydrate. It dissolves readily and by avoiding calcium altogether you have no chance of limescale or gypsum deposits in the machine. The Matt Perger / Barista Hustle water recipes use that approach: https://www.baristahustle.com/blog/diy- ... o-bottles/

Irishespresso wrote:Shoot one other thing I wanted to ask about was a simple calculator for building water. I have a complicated excel based program I used to use for beer brewing water but it is more complicated than needed as it takes into account malt roast and all sorts of other things. I downloaded the file from espressoschool-dot-com but it looks like there are errors in some of the formulas as certain things don't change with different inputs.
I've tried a few spreadsheets, mostly from the beer brewing community and haven't found them useful. I do better just calculating from basic chemistry based on molar masses of various salts. One that I did think was useful and reliable is the one from Marco Wellinger, discussed here: Mixing three waters (The .xlsx can be found here) .
Pat
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Irishespresso (original poster)

#4: Post by Irishespresso (original poster) »

Appreciate the response! Mixed up a couple gallons based on the BH water profile from that link. Water itself tasted pretty good and only had one shot this morning which was probably mostly my old water still in the boiler. I'll probably keep it simple for now unless I'm not happy with the taste.