Water chemistry is one of the most important factors when it comes to brewing beer. Regular water, including both tap and spring water, contains organic materials and inorganic minerals. These naturally-occurring “impurities” will affect your beer and determine whether or not you can (or should) use that particular water for brewing.
Before brewing, you should test your water for the existing mineral content. This will help you build a water profile that you can then adjust as needed.
There are a few things you want to look out for when you test your water chemistry:
- pH and alkalinity
- Sulfate (SO4)
- Chloride (Cl)
- Magnesium (mg)
- Sodium (Na)
Another option is to use distilled or deionized water to give you a “blank slate” in terms of minerals. You can learn more about deionized water (and how it differs from distilled water) here.
pH and alkalinity
Knowing the pH is important when you mash. Ideally, your mash should be in the range of 5.2 and 5.6 (slightly acidic). You want to avoid your pH being too high because that can extract tannins and other off-flavors from your mash. Too low, however, and you’re going to have a tart beer (unless if that’s what you’re going for). You also want to monitor alkalinity. The higher the alkalinity, the more acid you’re going to need to lower your pH if it’s too high.
Sulfate and Chloride
The amounts of sulfate and chloride you want in your beer are directly determined by what style you’re brewing. Essentially, more chloride leads to a more malty beer where there is enhanced fullness and malt sweetness. On the other hand, more sulfate in the brew means the hops will shine, producing a drier, more bitter beer. This is more ideal for brewing IPAs where you want that bright, grapefruit flavor of hops.
Calcium and Magnesium
Calcium and magnesium directly affect how “hard” the water is. The higher content of these minerals leads to harder water. Hard water actually enhances yeast flocculation, hot break, and prevents beer stone.
Sodium, commonly known as salt, is used to round out the malt flavors in your brew. Too much, though, will lead to a salty beer, which may or may not match your style.
Whether you’re compensating for the water chemistry of your tested water or are looking to build a water profile from distilled/deionized water, there are brewing salts and chemicals you can use to adjust your brewing water (to a degree).
Here are some salts and chemicals you can keep on hand to adjust your brewing water as needed:
Gypsum (calcium sulfate)
Calcium sulfate is useful for adding calcium and sulfates to the water, enhancing the hoppy “crispness.”
Potassium Metabisulphite or Campden Tablets
These will rid your water of chlorine or chloramines, which affect the taste.
Calcium carbonate can be used when making dark beers with soft water. It is only effective when you add it directly to the mash.
Calcium chloride increases calcium and chloride, and lowers mash pH slightly.
Epsom Salt (magnesium sulfate)
Magnesium sulfate increases magnesium and sulfate and can be used to add “crispness” to the hoppy bitterness.
Baking soda increases the alkalinity and mash pH if your pH is too low and/or has low residual alkalinity.
Using non-iodized table salt can increase sodium levels.
You can use lactic acid to decrease the mash pH.
What product(s) you need and in what quantities are going to depend on your water chemistry and the type of beer you’re looking to make. You can find other brewing aids, including acidulants and filter aids, on Ingredi.com.