appreciate thoughts on what you think would be the better option for espresso and if my math looks correct.
each would be equally easy to do.

OPTION 1:

-> Poland spring 1 gallon jugs (heres the last water analysis report):
https://static1.squarespace.com/static/ ... ated-2.pdf

it lists alkalnity as 11-21.

So i would bump the alkalinity of each gallon jug by 30. So that it would get the alkalinity to range of 41-51.

to do this:

1. create concentrate:
using food grade Potassium Bicarbonate Powder.
add 19 grams Potassium Bicarbonate to 1 gallon water.

So now 15 grams of this concentrate added to 1 gallon water = 10ppm alkalinity bump.

2. So to bump alkainity by 30.
I would add 45g of the concentrate to each 1 gallon of poland spring bottle

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VS.
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OPTION 2: rpavlis water

if i understand is just a flat 50 alkalinity with nothing else??

So i would create the same concentrate

1. create concentrate:
using food grade Potassium Bicarbonate Powder.
adding 19 grams Potassium Bicarbonate to 1 gallon water.

now 15 grams of this concentrate added to 1 gallon water = 10ppm alkalinity bump.

2. bump 1 gallon of distilled water so that it has 50 alkalinity.
adding 15 grams of concentrate to 1 gallon of water = 10ppm alkalinity bump.
So I would add 75g of the concentrate to each 1 gallon of if Distilled water so that i get the alkalinty of 50.

If you're pulling classic espresso and you're happy with the taste, I'd go with RPavlis with either the original potassium bicarbonate or baking soda. It's simpler and there's no question around the variability of the composition. ("My espresso changed taste. Oh, the water changed between last batch and this batch.")

If you're pulling shots of filter roasts, there is reasonable agreement that the water composition can make a significant difference in flavor. I'd go with RO/DI (or distilled), mix your own GH and KH concentrates, and decide what tastes best for you, your choices in coffee, and your gear.

I ran through your calculations - they look fine.

Given the choice between using Poland vs de-ionized I think convenience is the decider. For me that favors de-ionized because I can refill that at the store at a very reasonable price and no containers to throw in the recycle bin. If convenience is about equal I'd still go with de-ionized. As Jeff mentioned it is consistent. Poland comes from different springs in Maine, and they are all fairly similar but not identical. And that up to 15 mg/L chloride ion in the Poland Spring water is not ideal.

HBchris wrote:OPTION 2: rpavlis water
if i understand is just a flat 50 alkalinity with nothing else??

Yes. Zero hardness, and also zero for chloride, sulfate, silica, etc. Nothing that might cause scale or exacerbate corrosion.

With rpavlis you can go lower on the bicarbonate if you prefer the taste. Dr Pavlis said that for some coffees he preferred the taste if he used a half strength version of his recipe. Espresso tolerates way more alkalinity than pourover so if you want to evaluate this be aware that you are more likely to detect a taste improvement from the lower alkalinity if you are cupping or making pourover coffees.

thanks

I was thinking if i did the rpavlis water to modify it, so that it has some level of hardness (but a low level that definitely wouldn't cause scale). Just dont know if i can wrap my head around having 0 hardness.

If so what would you recommend. I was thinking perhaps 50 alkalinity, 30-40 hardness? 40 alkalinity, 30-40 hardness ? As a good balance.
If I was going to add some hardness, should i use magnesium carbonate or magnesium sulfate to create the concentrate? was looking specifically at either:

https://www.amazon.com/BulkSupplements- ... r=8-6&th=1

or

https://www.amazon.com/Magnesium-Sulfat ... r=8-8&th=1


How would i go about creating a 1 gallon jug magnesium concentrate?

and then how much of this concentrate would i need to add to my 1 gallon distilled water bottle for each 10 hardness bump or for a 30 hardness bump.

Or would it be easier to add the magenisum powder directly, and skip making the concentrate jug. My acacia lunar scale reads in 0.1g resolution.

Sorry for all the questions... i want to get this right...definitely appreciated.

HBchris wrote:If so what would you recommend. I was thinking perhaps 50 alkalinity, 30-40 hardness? 40 alkalinity, 30-40 hardness ? As a good balance.

I happen to be agnostic about whether you need any hardness minerals at all in your brew water. Admittedly my own recipe contains hardness minerals, but I can't say that my water recipe brews better tasting coffee than plain old rpavlis would.

HBchris wrote:Just dont know if i can wrap my head around having 0 hardness.

One thing to keep in mind is the fact that the liquid flowing through the puck is going to be loaded with minerals even if there are none in the brew water. Tons of potassium but also quite a bit of magnesium. The magnesium content in an ash analysis of a 30 ml espresso shot is about 25 mg of magnesium. Even if you used a really hard 100 GH water recipe based on magnesium salts, the amount of magnesium ion that comes in with 30 ml of the brewing water would be only 0.7 mg.

HBchris wrote:If I was going to add some hardness, should i use magnesium carbonate or magnesium sulfate to create the concentrate? was looking specifically at either:
https://www.amazon.com/BulkSupplements- ... r=8-6&th=1
or
https://www.amazon.com/Magnesium-Sulfat ... r=8-8&th=1

The Epsom salt is relatively soluble and is what practically everyone uses as a soluble source of relatively non-scaling hardness. To do the math with Epsom, you use the molar mass of magnesium sulfate heptahydrate, which is 246.5 gram/mole. So if you were to add 23 g of Epsom to a US gallon of pure water you would have a ~25 mmol/L concentrate. It may take some time to dissolve fully. If you then add 15 ml of that concentrate to 1 US gallon of brewing water it would give you a magnesium bump of about 0.1 mmol/L, which is 10 mg/L CaCO3 equivalent.

If you use the magnesium carbonate it gets more iffy. The Bulk supplements stuff is a little variable about exactly what mineral is in there. The label you pictured indicates a mineral with 24% magnesium content, not the 29% you expect from truly pure MgCO3. But that's easy to adjust for once you have the label of the product you have in your hands. (more geeky details can be found here: An all carbonate water recipe (cloudy concentrate, no sodastream) The advantage of the carbonate over the sulfate is that it has no sulfate ion. Also it provides a bump in both hardness and alkalinity. But the big disadvantage is that it will not fully dissolve at high concentrations.

thanks so much for the detailed reply, Pat.

I think i will go with the Magnisum sulfate, this one:

https://www.amazon.com/Magnesium-Sulfat ... r=8-8&th=1

just double checking, If i understand correctly

i will create the concentrate by putting: 23 g of this ^^(Magnesium Sulfate - Heptahydrate) into 1 gallon of distilled/pure water.

and then each 15g of concentrate added to a 1 gallon of brewing water will give me the brewing water a 10 hardness bump?


As a good baseline, for espresso (i use a mixture of roasts medium, as well as some light roasts. Usually nothing very dark),
if I wanted a little bit of hardness, but an amount that definitely wouldn't scale. What would you recommend in terms of Alkalnity and magnisum sulfate hardness, i should go with?

50 alkalnity, 35 hardness?


of course appreciated

HBchris wrote:i will create the concentrate by putting: 23 g of this ^^(Magnesium Sulfate - Heptahydrate) into 1 gallon of distilled/pure water.
and then each 15g of concentrate added to a 1 gallon of brewing water will give me the brewing water a 10 hardness bump?

Yes. It's probably worth mentioning that this concentrate needs to be in a separate bottle than your bicarb concentrate. Put the two together and you'd get a precipitate.

If you want to see the calculation:

HBchris wrote:As a good baseline, for espresso (i use a mixture of roasts medium, as well as some light roasts. Usually nothing very dark),
if I wanted a little bit of hardness, but an amount that definitely wouldn't scale. What would you recommend in terms of Alkalnity and magnisum sulfate hardness, i should go with?

50 alkalnity, 35 hardness?

I think that would be reasonable. That would put you in the ballpark of the "70/30" recipe that was advocated years back as a good starting point by the Five Senses coffee shop in Australia. At that level of alkalinity you could even try twice that amount of hardness and it still should not scale. (An early Barista Hustle recipe using Epsom and bicarb had a hardness of 100 and alkalinity of 50, and people reported seeing no scale after using it in their espresso machines.) If you don't see a taste improvement you can leave the mag sulfate out.

thanks so much Pat,
ordered the magnesium sulfate.


would you expect a 1 to 1 correlation with the TDS meter.

For example if i added 50 alkalinity bump to pure/distilled gallon jug. Would you expect the TDS meter to say 50?
And the same question for the magnesium hardness, if i added 35 to a hardness bump to a pure/distilled gallon jug, would you expect the TDS meter to read 35?

And if i did both the alkalnity 50 bump and hardness 35 bump, the TDS meter should read 85? Was thinking this could be a good check that everything i did was correct.

Or doesnt exactly correlate 1 to 1 with TDS.

HBchris wrote:For example if i added 50 alkalinity bump to pure/distilled gallon jug. Would you expect the TDS meter to say 50?
And the same question for the magnesium hardness, if i added 35 to a hardness bump to a pure/distilled gallon jug, would you expect the TDS meter to read 35?

And if i did both the alkalnity 50 bump and hardness 35 bump, the TDS meter should read 85? Was thinking this could be a good check that everything i did was correct.

It doesn't easily correlate to KH and GH values. Some geeky discussion as to why can be found here: Does Kh ppm + Gh ppm = TDS ppm?

If you are using a typical inexpensive TDS conductivity meter, which uses a linear factor of 0.5 to convert conductivity in µS/cm to PPM TDS , and if you measure with the water at 25 ℃, you should read about:
~ 60 ppm for the 50 ppm alkalinity rpavlis potassium bicarb water
~ 100 ppm after you add enough mag sulfate to bump it to 35 ppm hardness and 50 ppm alkalinity

P.S.
To get conductivity numbers for recipe waters I generally cheat and use a trustworthy online calculator - - https://www.aqion.onl/show_ph

just an update, i made the two concentrates.

added 75g of potassium bicarbonate concentrate (50 alkalinity) + 53 magnesium sulfate concentrate (35 hardness) to 1 gallon distilled water
and got 95 TDS on my cheap tds meter.
Which is pretty close to your estimate.

I came across:
https://www.baristahustle.com/blog/diy- ... pes-redux/

which had a lot of the recipes tending to be around that 30-40 alkalinity mark...
(definitely dont want any scale or corrosion)

So as a starting point, i am debating making my resulting water have one of the following:

alkalnity in range 40 - 50, hardness in range of 35 - 50, Curious if you have a preference in terms of how much of each of these as a good starting point, or different recommendation.

50 alkalinity 50 hardness
50 alkalinity 40 hardness
50 alkalinity, 35 hardness
40 alkalinity, 40 hardness
40 alkalinity, 35 hardness

?



of course appreciated