Another set of water questions...

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
day
Posts: 1316
Joined: 9 years ago

#1: Post by day »

Well, I have been reading again about water to better understand it and am overall a little confused. In the Long Facts it says
"The first was boiled hard water, at 100 hardness, 50 alkalinity. This
is ideal for brewed coffee, and will be the water one gets out of an espresso temperature boiler
whenever one runs anything harder through the machine."

This 100/50 is the highest rated in espresso taste in the Long Facts.

I was looking to get a zerowater system and add back in minerals. It sounds from the above that he is saying that just using tap water and running it through the espresso machine will produce the ideal 100/50, but require more frequent descaling?

Also, what is the current consensus, if I do use the zerowater, what should I be adding in? Potassium bicarbonate? Something else?

Water is an area I never really nailed quite right, and have just done various things I have read without really understanding it...and I never really understood how drastically it can affect the flavor until taking my Pavoni to the beach and being unable to produce a dirnkable shot...long past time to understand it, but man there is alot of information that goes way back....
Yes, i you per this on an iPhone

brianl
Posts: 1390
Joined: 10 years ago

#2: Post by brianl »

day wrote:I was looking to get a zerowater system and add back in minerals. It sounds from the above that he is saying that just using tap water and running it through the espresso machine will produce the ideal 100/50, but require more frequent descaling?
All tap water is different and you'll need to measure it yourself or look at city water reports. Jim happens to live in chicago, which has 150ppm water.

Adding back potassium bicarb will not increase hardness, but TDS and Alkalinity. The latest trend is adding back magnesium for hardness.

day (original poster)
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#3: Post by day (original poster) replying to brianl »

Then why did his article read "when one runs anything harder?"

On the zerowater, would one then use the zerowater, and add approx 70ppm magnesium?
Yes, i you per this on an iPhone

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homeburrero
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#4: Post by homeburrero »

Assume Long Facts is Jim's Insanely Long Water FAQ, so those numbers are the conventional measures of hardness and alkalinity as CaCO3. Also treating ZeroWater as essentially pure (0 ppm) water, here's a quick calculation:

100 mg/L calcium hardness as CaCO3 would be 1 mmol/l calcium. If you used pickle crisp (CaCl2 + 2H2O, which has 147 mg/mmol ) you would need to add 147 mg/l. Works out to 0.55g of pickle crisp per gallon of Zero water. Note that this would give you a chloride ion content of 35.5 mg/l, which some would worry about because of chloride and corrosion. (For example, La Marzocco recommends no more than 30 mg/L chloride in their machines. Synesso recommends zero chlorides.) But if your alkalinity is high enough ~35 mg/L chloride may not be a serious concern.

50 mg/L alkalinity as CaCO3 would be 0.5 mmol/l CO3, equivalent to 1.0 mmol/l HCO3. If you used sodium bicarb (NaHCO3, which has 84 mg/mmol) you would need to add 84 mg/l. Works out to 0.36g of sodium bicarb to gallon of Zero water. This would give you a sodium ion level of 23 mg/l, which is reasonable (SCCA recommends 10 mg/L as ideal, less than 30 mg/L as OK.) If you wanted to use potassium bicarb (KHCO3, which has 100 mg/mmol) you'd need slightly more - 0.41g per gallon.

Since you put 147mg/l plus 84 mg/l of solid stuff in, you might think you'd end up with a TDS meter reading of about 231 mg/L. It would be lower. Some of the pickle crisp is water, and the two additives can react together to produce H2O and CO2 (2 NaHCO3 + CaCl2 => CaCO3 + CO2 + 2 NaCl + H2O). Also, TDS meters typically read a little lower than actual dry residue TDS.

Note: You can get hardness via magnesium instead of calcium, and get magnesium sulphate in the form or Epsom Salt ( MgSO4 + 7H2O, which has 246 mg/mmol). So you could add 0.92g of Epsom salt per gallon of zero water and hit your 100 mg/L hardness target. Then you would have sulphate rather than chloride, which may be less of a corrosion concern, and magnesuim rather than calcium, which may be less of a scale concern. Or do half of each (0.22g of pickle crisp plus 0.46g of Epsom salt per gallon.)

Edit: Immediately after initially posting I had to make a quick correction because I underestimated the amount of sodium bicarb by a factor of two. I've made this mistake before, is easy to get wrong. 50 ppm alkalinity (as CaCO3) would indeed be 0.5mmol/l of CaCO3, but the same equivalent of bicarbonate (HCO3) would require 1 mmol/l. I quickly corrected my initial numbers.
Pat
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brianl
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#5: Post by brianl »

I actually use zero water mixed with filtered tap water to get at around 25ppm. Then add a magnetism sulfate mix to get to 50ppm. Then I get to 90ppm adding potassium bicarb.

I use a tds meter because it's the easiest even though it's not the most precise. My hardness and alkalinity after this is about 50ppm each

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homeburrero
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#6: Post by homeburrero »

brianl wrote:I actually use zero water mixed with filtered tap water to get at around 25ppm. Then add a magnetism sulfate mix to get to 50ppm. Then I get to 90ppm adding potassium bicarb.
Very reasonable in my opinion. I do something similar - mix ZeroWater with charcoal filtered tap and add a tiny pinch (per gallon) of bicarb.
Pat
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