I finally started messing with making my own brew water lately. The difference is pretty tremendous coming from clean but soft SF Bay Area water. Anyway, I've tried a bunch of combinations of magnesium sulfate and sodium bicarbonate, and I'm looking to try adding calcium. Any recommendations on a form? I'm looking at calcium chloride as that should be readily soluble but know some people object to chlorides and consider them bad for espresso machines. Ignoring that, are they fine for pourover?

Also, anyone compared potassium bicarbonate to sodium? I've heard theoretical justifications but not taste ones.

There's a cool technique for adding calcium carbonate, but I'd rather not bother with a sodastream. http://grindscience.com/2015/08/making- ... pe-so-far/

I've also considered just using tap water charcoal filtered as a base, since it has almost exclusively calcium hardness, but I don't want to rely on that and it's very soft anyway.

Here's a link to a post from 2009 by an old member, Adrian, drdna from whom I haven't seen a post in years...anyway I have reason to believe this is accurate...go about half way down the page...He is talking about using pure r/o water then adding the missing minerals to the top of the coffee puck.

Does reverse osmosis water filter prevent scale buildup?

NoStream wrote:I finally started messing with making my own brew water lately.

Yeah, me too. For my coffee-life I've been a RO user, but recently started barista hustle's recipe, which is kindergarten simple to make, but yeah, no calcium. Which calcium and how much, are the two questions I can't answer, yet. I got some food grade calcium chloride today but I don't know if it's anhydrous or dihydrate, the molar mass difference between the two is ~25%; dihydrate has less, (per here: http://www.reefcentral.com/forums/showt ... ?t=1660509) and the recipe I found assumed dihydrate. I sent an email to the company for the exact molecular formula, but, yeah, that was all today so I'm currently in email limbo. There is the trick that dissolving anhydrous CaCl2 releases a bit of heat, so if that doesn't happen then I'll know I have dihyrdate, but it's in the packaging, and sometimes I'm lazy, plus I only got a tiny amount and expect to do some trial and error. I should have an answer in a few days.

In the meantime, I did find this thread. Turns into a bit of a tease, never comes out and gives an exact recipe, but it might help. Water formula.

Do you still prefer the wave over v60? My tests will be on a v60; I ain't got no wave.

Anyway, glad to see you're back on the forums. In my own search for coffee veritas, I've found your posts to be of great help; and, hey, what's the state of Bring Me Coffee or Tea? I binged that site

Turns out the wheel has already been invented. Spencer Webb of Grindscience.com, same guy as the "sodastream" guy, on his site earlier posted about a CaCl2 water recipe. I made his 50/50 recipe, which means Mg and Ca are in a 1:1 ratio. What I used was Modernist Pantry's CaCl2 https://www.amazon.com/Calcium-Chloride ... B00BLPNJLK. It is anhydrous, so, per Spencer's stock recipe, you only add 37.746 grams. The bag is 50g. For final product the bag should yield 946L, if my maths are correct

Is CaCl2 "the best source?" Assuming taste is your main objective, then probably not. Spencer is very blunt that his sodastream recipe that uses CaCO3 is better-but you will get scale. On the other hand, as a method sort of the sodastream, I think CaCl2 is very worthwhile. Compared to RO, His 50/50 recipe gives enhanced sweetness, and a new and wonderful creaminess that I was not expecting, but love and might be addicted to. The coffee tastes "uplifted" if that makes sense. I haven't noticed any scale, though I've only used it for about a week--V60s, no espresso, bonavita gooseneck kettle.

The CaCl2 I got mixes medium-well in room temp water; I actually made 1/5th of his stock, but at half strength thinking the extra water would help dissolve it--just remember to then add double what he says when going from Calcium stock to final product. I shook the stock for about 30 secs, and got a cloudy mixture with very fine particulates. I pipetted out of that to make the first batch. It tasted like I got out of it what you could expect, and the next day I needed more . The Ca stock had sediments at the bottom of the bottle, about 1/8th or so of the original amount. I shook it again and got the cloudy mixture and pipetted out of that. It seems to be "good enough."

http://grindscience.com/2016/03/dissolv ... on-coffee/
http://grindscience.com/2015/03/making- ... roduction/

He recommends a scale accurate to .01g, with bonus points for .001g. I used .01g. His comment sections are worth reading. They flesh out some good stuff that isn't retrofitted to the original post, like in-between the 50/50 and sodastream recipe he said he experimented with 60/40 in favor of Ca, and I've tried this and noticed a worthwhile improvement: reduction of bitterness and better sweetness, which Webb would say is caused by a reduction of sulfates stemming from the Epsom salts. 60/40 is now what I make.

This could also be of use: 70/30 Water

All these water formulas kind of take for granted that you start with RO water, which I have, but if you're coming from "soft" water you'll have to do some calculations which I have no idea how to do