The Significance of Water Chemistry in Beer Brewing
Most brewers are familiar with the three primary ingredients in beer brewing: malt, yeast, and hops. However, there is a fourth ingredient that often goes unnoticed: water. Water plays a crucial role as it constitutes over 90% of your beer. It is often said that the key to making an outstanding beer lies in understanding the chemistry of your brewing water and how it interacts with the beer you are making.
In this article, our brewing experts will guide you through the importance of water chemistry in beer brewing. We will discuss water sources, the different ions present in water, and their impact on your beer. While water may seem like a simple ingredient, it actually consists of complex chemicals such as salts, ions, and minerals that can be evaluated and adjusted during the brewing process.
For novice brewers, a general rule of thumb is that if your water is drinkable and tastes good, it is suitable for brewing. However, there are certain water sources that you should be aware of.
Municipal Water Sources
Most municipal water sources are treated with chlorine or chloramines to prevent bacterial growth as the water travels from the treatment plant to your home. Unfortunately, these treatments can harm the growth and health of your yeast.
Well and Surface Water
Well and surface waters often contain high levels of metallic ions, such as iron, which can impart a metallic taste to your beer.
Store-Bought Water
Generally, store-bought water is the safest option and provides consistency in quality.
Top Tip
: Avoid using volcanic waters, as they contain excessive minerals and salts that can negatively affect your beer.
Troubleshooting
If you find that your beer has an undesirable taste, here are some suggestions for improvement:
My beer tastes like band-aids, medicine, or disinfectant:
This is commonly caused by chlorine and chloramines, which react with yeast and form chlorophenols. To remove chlorine and chloramines from your water, consider using a carbon filter or boiling the water for 7 minutes before use. Allowing the water to sit for a while before use can also help chlorine evaporate.
My beer tastes metallic, like pennies or blood:
Iron or other metals present in the water source often cause this issue. Chemical treatment or water filtration can help remove these metals.
Only my pale beers or dark beers taste good:
Your water may have a mineral ratio that is more suitable for either light or dark beers. If you prefer one style over the other, you can continue brewing that particular style. Alternatively, you can explore new water sources to enhance the other beer style.
Water Chemistry
When you are ready to take your great beer to the next level, it’s time to consider the chemistry and chemical composition of your water.
Important Factors Related to Water
pH Levels
The pH levels throughout the brewing process need to fall within specific ranges to optimize the brewing environment:
1. During the mash, the pH should be between 5.2 and 5.6, which allows the enzymes in the mash to function optimally.
2. The pH drops slightly during the boil due to sugar reactions and the addition of hops.
3. As fermentation occurs and yeast produces alcohol, the pH of the wort decreases to around 4-4.5, providing protection against spoilage organisms.
4. Note: Sour beers can have a pH as low as 2 in extreme cases.
pH levels can be adjusted at any stage of the brewing process using acids, bases, buffers, and salts. To calculate pH adjustments, you can use the Grainfather water calculator, which takes into account the pH of your source water, the grains in your beer, and the beer style you are brewing.
Water Ions
Once you have addressed the pH, it’s important to consider the specific ions present in your brewing water. These ions vary in concentration depending on your water source and each one contributes to the final taste of your beer, either directly or by influencing the perception of maltiness or hop character.
We are particularly interested in the following ions: calcium, magnesium, bicarbonate (alkalinity), sodium, chlorides, and sulfates. So, what effects do these ions have?
Calcium
Calcium is an extremely important mineral for brewing water. It does not contribute much to flavor but plays vital roles in:
1. Adjusting mash acidity (especially when using alkaline water)
2. Assisting enzyme activity
3. Enhancing hop bitterness
4. Reducing haze
5. Decreasing wort color.
Calcium is commonly added in the form of calcium sulfate (gypsum) or calcium chloride. Calcium carbonate (chalk) used to be a popular option, but it is now less favored due to low solubility in water and limited effects compared to gypsum and calcium chloride.
Magnesium
Magnesium promotes proper enzyme activity and serves as a yeast nutrient. In small quantities, it can enhance the flavor of the final beer.
Sulfates & Chlorides
The ratio of chloride to sulfate is significant in every beer style as it determines the “balance” of the beer.
Chlorides enhance the flavor of the beer and contribute to fullness in the mouthfeel, which is crucial for certain beer styles. They also increase sweetness and mellowness, making them desirable in malt-forward beers. Additionally, chlorides improve long-term beer stability and clarity.
Sulfates are particularly important in hoppy beers as they enhance hop character, aroma, and the perception of bitterness.
If the sulfate level is proportionately higher than chloride, the beer will have a hop-forward balance. Conversely, if chlorides predominate, the beer will lean towards a malt-forward balance. If they are roughly equal, the beer will have a balanced profile.
Sodium
Sodium can be used to increase alkalinity in brewing water and can improve the flavor and mouthfeel of the finished beer. However, excessive levels of sodium can result in a harsh, salty taste and can be harmful to yeast.
Top tip: Never use iodized salt, as the iodine content is toxic to yeast.
