Lesson 2 - Brewing Water Sources and Treatment
This lesson introduces water as an ingredient for brewing. It explores the water cycle, sources of water and potability standards. It also examines some characteristics of water (hardness and alkalinity) and their effects on the brewhouse. Finally, the lesson investigates the methods of water analysis.
Municipal water
A municipal water supply may not come from one source; it could in fact come from a mixture of several sources – each source having a different mineral composition.
These sources could be blended into one source, which is then supplied to the community. Alternatively, the municipal water supply may alternate sources, supplying water of different compositions at different times. This situation can be problematic to the brewer, as they will need to adjust their own water treatment or mineral additions accordingly.
The main advantage of a municipal water supply is that the water should comply with the local drinking legislation, thus would be potable. However, the water is likely to be chlorinated to meet microbiological standards. Therefore, the brewer will need to remove the chlorine before brewing with the water.
Chlorine dissolved in brewing water can lead to off-flavours in beer, such as chlorophenol. High levels can damage membrane filters. Chlorine in contact with water and as a dissolved gas can potentially be aggressive to stainless steel. Localised pitting and stress corrosion can be an additional hazard with damp chlorine gas, if the temperature is high enough.
This section has covered the main water sources available to a brewer, but the water available to the brewer may not be potable. So how does the municipality make their source water potable? (Note: if a brewery utilises water directly from surface or ground water, as opposed to the municipality, they may need to install similar equipment to meet potability standards.)