Lesson 4 - Brewing Water Composition and Impact
This lesson deals with the influences of water composition on brewing equipment, the brewing process and beer quality. It will cover the positive and negative impacts that the various compounds found in water have on beer. We will explore the recommended water specifications for brewing key beer styles. We will also examine how to correct levels of some of the key salts within water.
Effects on yeast
In our tables earlier we referred to several compounds as affecting yeast, these included zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), manganese (Mn2+), copper (Cu2+), iron (Fe2+) and potassium (K+). These compounds all affect yeast enzymes, mainly as co-factors.
Did you know?
Co-factors cannot catalyse a reaction, but they help enzymes to do so.
Calcium is also essential for yeast flocculation, as it promotes the binding of yeast cells.
If the required compounds are not available in the right quantities within water and ultimately the wort, this can negatively affect the yeast’s metabolic pathways. This could cause off-flavours, reduced ethanol production and poor yeast crops.
Point of reflection: We have seen that the various chemicals and minerals in the water can directly affect beer flavour, as well as yeast quality. How can the various compounds found in water affect colloidal stability?
As a quick refresher, colloidal stability refers to ‘haze’ in the beer. A colloidal system is the presence of one substance suspended in another. Protein particles in the beer could be causing the haze; or it could be yeast cells. High colloidal stability means that the beer has no haze. Low colloidal stability suggests that the beer is hazy.
Give yourself 5-10 min to think about this and then click ‘Next’ and continue with this lesson.