Water & Water Treatment

(Jan/Feb 1986)

The following was taken from a September 1982 Crescent City Homebrewer’s Education Series.

The basic premise of brewing: hard, neutral water is necessary for brewing a light/pale lager or ale, while soft, neutral water is desirable for brewing a dark lager, porter or stout.

What is hardness?

Hardness relates to the amount of calcium and magnesium salts (bicarbonates, carbonates, sulfates) that are in solution.  We can ignore the bicarbonates and carbonate content of our water because these salts will precipitate out upon boiling.  However, we must be concerned with the amount of calcium and magnesium sulfate in the water because these two salts are unaffected by boiling and will remain in solution as permanent hardness!

                                                                                Table 1

Permanent Hardness                                         Classification

    0 – 100  ppm                                                    Soft

100 – 200 ppm                                                    Medium Soft

200 – 400 ppm                                                    Moderately Hard

400 – 600 ppm                                                    Hard

Above 600 ppm                                                   Very Hard

                                                                                Table 2

Permanent Hardness                                     Classification

Ozone                    10.3 ppm                               Soft

Kentwood             3 ppm                                    Soft

S&W Board          99.9 ppm                               Soft

It is important to note that all three waters have a low permanent hardness and are considered to be soft.

How hard should the water be?

That depends of the type of beer you plan to brew!

                                                                                Table 3

Pale Ale                                                                 Hard Water

Light Ale                                                                Hard Water

Medium (Mild) Ale                                              Moderately Hard Water

Dark (Brown) Ale                                                Soft Water

Porter                                                                     Soft Water

Stout                                                                      Soft Water

Light Lager                                                           Soft to Hard Water

Pale Lager                                                             Miller (1981)* (360ppm sulfate)

Dark Lager                                                            Soft Water

Is permanent hardness really that important?

If you use canned or powdered malt extract for your light beers or ales, then the permanent hardness of the water is not that important.  The main reason for this is that malt extract is made by boiling the grain solution until the water is evaporated, however the minerals that were contained in the water remain in the malt extract!  Still, many homebrewers include gypsum (calcium sulfate) in their recipes, as it acts to mellow the hop flavor, and produces a drier beer with greater clarity.  Permanent hardness is very important when making an all grain beer.

How much gypsum do you add?

According to Miller (1981)*, a ½ teaspoon (tsp.) of gypsum per US gallon of water will yield approximately 510 ppm (150 ppm Ca + 360 ppm SO4) of permanent hardness.  Therefore, a ½ tsp. of gypsum per gallon of Ozone or Kentwood will give you hard water.  For moderately hard water, just add ¼ tsp. per gallon.  If you must use tap water, use ¼ tsp. of gypsum for moderately hard water or 3/8 tsp. per gallon for hard water.

References

*Miller, Dave  HOME BREWING FOR AMERICANS, Andover, England: THE AMATEUR WINEMAKER.