In my first try to make the concentrates for the TWW espresso recipe, I have mixed 3 g of Calcium citrate in 1 l of RO-water.
The meaning is to use 100 ml concentrate for a gallon.

It doesn't seem to dissolve as the mix is white and with a white sediment.

Maybe 3 g is too much for 1 l

Any advice ?

airborn wrote:Maybe 3 g is too much for 1 l

It is. Even 1 gram is a little more than will dissolve in 1 liter at room temps. I think the TWW folks went with calcium citrate because it worked well in their desire to have a single packet of dry powdered minerals that didn't chemically react or clump.

Thank you Homeburrero
Can I use it, if I shake it before 100 ml goes in a gallon?

What could be a substitute?

airborn wrote:Can I use it, if I shake it before 100 ml goes in a gallon?

Yes you can, I do something similar with my concentrate that has undissolved calcium carbonate. Shake well, then immediately add it to your final water, and allow time for it to fully dissolve in the final water.

airborn wrote:What could be a substitute?

One option would be to skip it entirely, and just get all your hardness from the magnesium concentrate. You could bump the Epsom dose from 1050 mg/gallon up to 1500 mg/gallon if you want the final total hardness to come out the same, but I would not. That TWW has a magnesium hardness of 113 mg/L and calcium hardness of 48 mg/L* giving you a somewhat high total hardness of 161 mg/L so I think you're fine skipping the calcium with that much magnesium sulfate. I'm not sure, but suspect that one purpose of the calcium citrate in TWW is that they are using the anhydrous form partly for its drying anti-caking properties in their powder mix. I would bump the potassium bicarbonate from 150 mg/gallon to 300 mg/gallon get the bicarbonate alkalinity up to about 40 mg/L. (The citrate would contribute to the alkalinity, so if you take that out you may want the bicarbonate alkalinity a little higher.)

If you wanted to keep that level of calcium hardness in the final mix you could use pickle crisp, calcium chloride dihydrate, which dissolves very well. Trouble with that is that it adds chloride, which may be a corrosion issue. If you add 226 mg of calcium chloride dihydrate to a gallon you would get 48 mg/L calcium hardness (as CaCO3) like you have in TWW, but you would also end up with 30 mg/L of chloride ion - perhaps unacceptable. If you did that, then for sure you want to double the amount of that bicarbonate to offset potential corrosion risk.


* Edit addition: 48 mg/L if they are putting 300 mg of anhydrous calcium citrate in each capsule. If using the tetrahydrate it would be closer to 42 mg/L. Both, of course, in conventional hardness units of CaCO3 equivalents.

I make my concentrate with calcium carbonate, except I go one step further and use carbonated water.

Calcium carbonate is insoluble in water. However, it reacts with carbonic acid that forms when water is exposed to carbon dioxide. Fizzy water is quite acidic and converts the calcium carbonate into calcium bicarbonate.

I use a Soda Stream, put in cold RO water, add my minerals (mostly calcium carbonate), shake it up till it is all nice and milky looking, then add carbonation with the Soda Stream. Leave it overnight in the refrigerator, the water will be clear and bright and all the powder in solution.

A lifetime supply of food grade calcium carbonate is like $5 on Amazon. Soda Streams are pretty cheap too.

Makes a nice whiskey and soda too.

Thank you for spending your time to answer me.

I might have to do some reading before I understand the difference between anhydrous calcium citrate and the tetrahydrate form -

Hello again

Now I have used my TWW espresso recipe for a week and I can clearly taste the difference between this and the bottled water I've used before.

TWW: 1050 mg magnesium sulfate, 300 mg calciumcitrate, 150 mg potassium bicarbonate per gallon of RO water

Before I used a danish bottled water called
Denice : bicarbonate 140 mg, sulfate 3 mg, cloride 11 mg, magnesium 13 mg, sodium 10 mg, potassium 3 mg, calcium 22 mg per liter

I liked the bottled water better .. but I don't know how this water affects my espresso machine.

I am not able to calculate the differences.

Can you ?

airborn wrote:I liked the bottled water better .. but I don't know how this water affects my espresso machine.
I am not able to calculate the differences.
Can you ?

I assume the numbers you provided are measures of mg/L as the ion. So
per: Good references on water treatment for coffee/espresso ...

Multibly bicaronate ion by 0.82 to get bicarbonate alkalinity:
140 * 0.82 = 115 mg/L alkalinity as CaCO3
(In this case, total alkalinity = bicarbonate alkalinity)

Multiply the calcium ion by 2.5 to get calcium hardness:
22 * 2.5 = 55 mg/L calcium hardness as CaCO3

Multiply the magnesium ion by 4.12 to get the magnesium hardness:
13 * 4.12 = 54 mg/L magnesium hardness as CaCO2

Add calcium hardness to magnesium hardness to get total hardness
55 + 54 = 109 mg/L total hardness as CaCO3

So compared to TWW, this has far more alkalinity, quite a bit less total hardness, but slightly more calcium hardness. And the calcium hardness and alkalinity are at levels where you expect some scale deposits (you would need to watch the machine and may need to descale periodically.)

That bottled water is nicely low in chloride and would be a good source of minerals. If you were to mix it with 50% or 60% distilled I think you would have excellent non-scaling water for machine health as well as taste.

Thank you again for your quality answers

I have blended this water after your suggestion :

One option would be to skip it entirely, and just get all your hardness from the magnesium concentrate. You could bump the Epsom dose from 1050 mg/gallon up to 1500 mg/gallon if you want the final total hardness to come out the same, but I would not. That TWW has a magnesium hardness of 113 mg/L and calcium hardness of 48 mg/L* giving you a somewhat high total hardness of 161 mg/L so I think you're fine skipping the calcium with that much magnesium sulfate. I'm not sure, but suspect that one purpose of the calcium citrate in TWW is that they are using the anhydrous form partly for its drying anti-caking properties in their powder mix. I would bump the potassium bicarbonate from 150 mg/gallon to 300 mg/gallon get the bicarbonate alkalinity up to about 40 mg/L. (The citrate would contribute to the alkalinity, so if you take that out you may want the bicarbonate alkalinity a little higher.)

It tastes better than TWW water in my opinion

Is this water ok with the espressomachine?

All I can test is tds = 152 and pH by a strip to app. 6
Seems moderate corosive in the langlier-index ( I might very well be wrong as I'm not at all good at this )

airborn wrote:Is this water ok with the espressomachine?

Yes - it will not scale because it has zero calcium that might form limescale or calcium sulfate deposits and it has bicarbonate alkalinity up in a range recommended by most manufacturers and SCA advice. (The bicarbonate buffers any acids that might contribute to corrosion.) I think you could experiment with even less magnesium sulfate and se if that tastes better. If you get that down to zero, and keep the 300 mg/gallon potassium bicarb you will be essentially the same as the "R Pavlis" water that many people on this site recommend.

You may find Matt Perger's World in Two Bottles recipes useful if you want to experiment with different hardness. Where he advises 1.68 grams of baking soda in a concentrate bottle you can use 2 grams of potassium bicarbonate. And for use in an espresso machine I think it best to just keep the alkalinity at around 40 - 50 mg/L, which would be 40 - 50 gram of the buffer concentrate per liter of final water.

Another handy tool for water experimenters is the spreadsheet that the Marco Wellinger shared with us a while back: Mixing three waters