Basic Water Chemistry :Part2

March 26, 2001 -- Ashville, NC

Last month we talked about the importance of the chemical composition of your brewing water, and how to find out just what is in your water. This month, we'll talk about how to use that knowledge to improve your beer.

To quickly review, all water contains dissolved ions. These ions have either a negative or positive charge, and impact the perception of your beer in varying ways. Adjusting the concentrations of the ions in your brew water will help you to achieve that perfect beer.

Ok, you've obtained information from your local utility, and you know what's in your water. Now what? It's just like anything in life, you have to know where you're going in order to get there. The easiest way to determine what your water composition should be is to compare your water against the water found in the world's brewing capitals. For the following beer styles, your water should approximate the water found in the following cities:

Beer Style Brewing Water
Pale Ale	Burton
Bitter	Burton
Mild	London
Brown Ale	London
Scottish Ale	Edinburgh
Porter	London
Sweet Stout	London
Dry Stout	Dublin
Pilsener	Pilsen
Light Lager	Pilsen
Dark Lager	Munich
Munich dark	Munich
Maerzen	Vienna
Bock	Munich
Dopplebock	Munich
Alt	Munich
Weizen	Dortmund
Dortmunder	Dortmund

Please be aware that the table above is only intended as a general guideline. If you want more detailed information about water profiles for specific styles of beer, consult the Classic Beer Styles series, or Ray Daniels' excellent book "Designing Great Beers."

So now you know what city's water you should be emulating. How do you find information about that city's water. Easy, click on the following link:

www.brewingtechniques.com/library/backissues/issue1.3/sidebars.html#table3

Compare your city's water profile to your beer style's city. Keep in mind that this type of chemistry is inexact. If your water profile is within 20 to 30 ppm, consider it a match.

Obviously, if your water is deficient in ions, you'll need to add more. Keep in mind, that there is no practical way to add only one ion. We add salts that consist of both a positively charged ion (cation) and a negatively charged ion (anion). Dissolving the salt in your brew water will add both ions.

Water treatment salts can be purchased in most homebrew stores for a minimal cost. If you decide to buy your salts elsewhere, make sure they are pharmaceutical grade salts. If not, the salt may contain harmful impurities. A pharmaceutical grade salt will contain the letters "USP" on the label.

If you need to add table salt, make sure it is not iodized. The literature I've seen is not in agreement, but some authors believe that the iodine impedes yeast growth. Personally, I don't see any reason to take this chance when non-iodized salt costs the same amount of money and is widely available.

The following list describes common brewing salts, the quantity of ions added by each, and an estimate of the relationship between weight and volume.

Sodium Chloride (NaCl) (Table Salt)
One tsp weighs 5.3g
One gram per gallon adds: 104 ppm Sodium and 160 ppm Chloride

Calcium Sulfate (CaSO4) (Gypsum)
One tsp weighs 4.8g
One gram per gallon adds: 62 ppm Calcium and 148 ppm Sulfate

Calcium Carbonate (CaCO3) (Chalk)
One tsp weighs 1.8 g
One gram per gallon adds: 107 ppm Calcium and 159 ppm Carbonate

Magnesium Sulfate (MgSO4) (Epsom salts)
One tsp weighs 3.4 g
One gram per gallon adds: 37 ppm Magnesium and 145 ppm Sulfate

Calcium Chloride (CaCl2)
One tsp weighs 4.8 g
One gram per gallon adds: 96 ppm Calcium and 168 ppm chloride

To add salts, calculate how much you need for the volume of water to be treated. Mix the salts with about a cup of water. Dissolve and mix the solution into the water to be treated. It's that easy!

Calcium carbonate will only dissolve in acidic solutions. To get around this problem, mix it with either wort or mash liquor instead of water. The low pH of those substances will dissolve the chalk in no time!

If you have too many ions, treatment is a bit harder. If your sulfate or chloride ion concentrations are too high, you have problems. There is no practical way to reduce these concentrations at home. Your best bet is to dilute with distilled water until you reach the desired concentration.

Excess carbonate can be removed by neutralizing with an acid solution. See my article on mash pH for more information on this topic.

Excess calcium and magnesium concentrations can be reduced somewhat. Boil the water to be treated for about 10 minutes and let cool. A white substance will form at the bottom. Pour your water off of the white powder. The remaining liquid will have less calcium and magnesium. The exact quantity to be removed depends on the carbonate concentration of your water. The more carbonate, the more calcium and magnesium can be removed.


Following these easy steps, will allow you to approximate any classic brewing water in your own kitchen. Enjoy!