Lesson 6 - Beer Flavour and Stability
In this lesson we will discuss beer flavour and beer flavour stability. This will include the effects raw material has on beer flavour, followed by a discussion on common taints, their flavours and consumer reaction. We will examine the flavour changes that occur during beer storage: focussing on oxidation reactions, the species of oxygen involved, and how we can utilise antioxidants to protect against aged beer flavour change. Finally, we will summarise the selection of raw materials and process optimisations available to improve beer flavour stability.
Taints in Beer
Taints in beer are described as the unwanted introduction of off-flavours. They are distinct from process off-flavours and arise outside of the process, carried by liquids, solids or gases. They can stem from contaminated raw materials, processing aids, additives, cleaning materials, lubricants, and packaging materials. Often, a taint will be at a level that dominates beer flavour and makes it unacceptable. It is therefore necessary to have rigorous tasting protocols in place to detect taints before the product is released into the trade.
We can consider taints in beer as deriving from three broad categories. Often, they can come from more than one category.
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Taints from cleaning materials
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Taints from contact materials
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Taints from brewing plant and processing