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.
Ground water
Surface water can seep into the ground, through the rock and soil layers and into ground water. The pH of ground water tends to range between 6.5 to 8.5. Ground water can remain underground for thousands of years, being exposed to high temperatures and pressures. This can cause the minerals and metals in the rocks to leach into the water. The water’s composition depends on what the rock or sand is made up of.
Since the primary water source in a particular area may vary between surface and/or ground water and depend on the topography and geology of the area, the mineral composition and water hardness can vary.
Water hardness is determined by the level of naturally occurring calcium (Ca2+) and magnesium (Mg2+) compounds in your water. A high level of these compounds means that the water is ‘hard’, whilst low levels make the water ‘soft’.
Some well-known brewing locations became famous largely due to their water and their suitability to brew particular beer styles. The ideal composition of the water used for beer styles is covered in the lesson dealing with the effects of water quality on beer.
Table: Water qualities of locations around the world (mg/L)
|
Beer Type |
Burton |
London |
Dublin |
Munich |
Pilsen |
Melbourne |
|
Sodium |
30 |
24 |
12 |
1 |
3 |
4.5 |
|
Magnesium |
62 |
4 |
4 |
19 |
1 |
0.8 |
|
Calcium |
268 |
90 |
119 |
80 |
7 |
1.3 |
|
Chloride |
36 |
18 |
150 |
1 |
5 |
6.5 |
|
Sulphate |
638 |
58 |
15 |
5 |
6 |
0.9 |
|
Carbonate |
141 |
123 |
315 |
164 |
9 |
3.6 |
|
Nitrate |
31 |
3 |
- |
3 |
- |
0.2 |
|
Total Dissolved Solids |
1226 |
320 |
625 |
273 |
31 |
25 |
A brewery could utilise both surface and ground water, especially if they have access to a spring or borehole for their water needs. In most cases, the water would need some form of treatment to ensure that it meets potable water requirements.
Before we look at water treatment options (see the raw water treatment section later in this lesson), we should remember that most brewers do not have access to their own springs or boreholes. They will instead rely on water supplied to them by their local water supplier or municipality.