The effects of various ions present in water:
Ca2+: This is an important ion for water hardness. Calcium will precipitate phosphorous in wort to reduce the pH. Calcium helps stabilize alpha amylase, improves runoff of worts from lauter tun, favors rapid and bright filtration, decreases wort color improves flocculation of trub and yeast, limits extraction of certain color and astringent substances.
Mg2+: Rarely greater than 30 mg/l (ppm) (Calcium maybe as much as 200 mg/l) Magnesium salts are more soluble than calcium salts and have less effect on wort pH and beer flavor.
Na+ & K+: Rarely present in high concentrations. Sodium gives a sour and salty taste. NaCl at 75-150 mg/l will give a desirable palate fullness. Potassium gives a salty taste but above 10 ppm inhibits certain enzymes.
HCO3-: Bicarbonate decomposes on heating. High concentrations give too high pH and flavor is affected. More potent in adjusting pH up than Ca2+ is at lowering pH. Should not exceed more than 50 mg/l.
SO42-: Sulfate contributes to drier more bitter flavor. Source of SO2 and H2S during fermentation.
Cl-: Chloride gives a mellow palate and palate fullness. Limits yeast flocculation improves clarity and colloidal stability.
ION COMPOSITION OF BREWING WATERS:
|
(mg/l or ppm) |
BURTON |
MUNICH |
LONDON |
PILSEN |
|
Carbonate Ratio |
100:25 |
100:100 |
100:86 |
100:71 |
|
Sodium |
30 |
1 |
24 |
3 |
|
Magnesium |
62 |
19 |
4 |
1 |
|
Calcium |
268 |
80 |
90 |
7 |
|
Chloride |
36 |
1 |
18 |
5 |
|
Sulphate |
638 |
5 |
58 |
6 |
|
Carbonate |
141 |
164 |
123 |
9 |