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.
Aldol Condensations
Separate aldehydes, or ketones, react to form larger carbonyl species. E-2-nonenal (T2N) may be produced by this route through a reaction between acetaldehyde and heptanal: catalysed by the amino acid proline. This results in the well-known cardboard flavour of aged beer. The extent of the staling flavour compound formation via this route is uncertain.