Just recording some simple calculations here on how to make san pellegrino from distilled/tap water.

San Pelligrino, content, milligrams per liter:

Calcium (Ca) 180
Chloride (Cl) 57.5
Bicarbonate (HCO3) 239.0
Fluoride (Fl) 0.6
Lithium (Li) 0.2
Magnesium (Mg) 52.3
Nitrate (NO3) 2.2
Potassium (K) 2.8
Silica (SiO2) 7.5
Sodium (Na) 57
Strontium (Sr2) 3.2
Sulfates (SO) 459.0

Some atomic weights from the periodic table:

Na 23, Mg 25, O 16, S 32, Cl 35.5, Ca 40,  K 39, C 12, H 1, SO4 Sulfate = 32 + 16*3 = 80, HCO3 Bicarbonate = 1 + 12 + 16*3 = 61, 2H2O = 4 + 32= 36, (OH)2 = 34

Some easy to obtain ingredients are Epsom salts, MgSO4, Gypsum CaSO4 – 2H2O you can get this as the asian store it’s used for making tofu, or a beer making place, they use it to add hardness to water, baking powder NaHCO3, Morton’s lite salt, 50% NaCl, 50% KCl, and table salt, NaCl, slaked lime, it’s used in cooking or pickling, Ca(OH)2, Potassium Chloride, KCl brewers use this for something, and Milk of Magnesia Mg(OH)2.

Unfortunately you can’t make the calculations work out with just the salts, I tried but it adds too much sodium if you want the bicarbonate to be right.  So I guess you have to use some hydrated stuff, like Milk of Magnesia and then add carbon dioxide so the (OH)2 becomes bicarbonate.

According to my calculations you can mix these ingredients for 1 liter of san pellegrino

700 mg caso4-2h20, 100 mg nahco3, 10 mg kcl-hacl, 130 mgof mg(oh)2, 80 mg of nacl

. . . which for 5 gallons is

13 grams of gypsum

2 grams of baking soda

.2 grams of morton’s lite just a sprinkle

31 grams of milk of magnesia (milk of magnesia is mostly water, which is why it seems like there is a lot here)

1.5 grams of salt

You have to add the carbonated water to this so it clears up, and helps everything dissolve, probably best to make a concentrated solution just 3 two liters of seltzer water and the above ingredients, mix for a while, give it a half hour until it’s no longer cloudy and then fill to 5 gallons.

I was reading some other guy making all kinds of waters from here:


And I wondered why he never included potassium, but now that I made my own recipe, I see it really is such a low amount, probably doesn’t affect taste.  His version gets the bicarbonate from slaked lime ca(oh)2, and the sulfates from epsom salts, while I do the reverse using gypsum for the sulfates and magnesium hydroxide for the bicarbonate.  His might be a better formula I’ll include it here, ‘s DIY San Pellegrino:

 Amount of salt to add for
1 liter 10 liters
Salt mmol/L mg g
NaCl 1.90 111 1.1
NaHCO3 0.00 0 0.0
MgSO4 . 7H2O 2.30 567 5.7
CaSO4 . 2H2O 3.42 588 5.9
Mg(OH)2 0.00 0 0.0
Ca(OH)2 1.77 131 1.3
CO2 0.00 0 0.0