Beer Aroma Compounds: Key Odorants, Off-Flavour Compounds and Improvement Proposals

Area of Science:

• Food Science
• Sensory Science
• Brewing Science

Background:

• Beer aroma is crucial for quality, influenced by volatile compounds from malt, hops, and yeast.
• Off-flavours can significantly degrade the sensory profile of beer.
• Understanding aroma-active compounds is essential for brewers to maintain product quality.

Purpose of the Study:

• To identify and describe key aroma-active compounds in beer, including desirable and undesirable notes.
• To develop a troubleshooting guide linking specific off-odours to their chemical origins and corrective actions.
• To provide brewers with strategies for enhancing beer aroma control and flavour stability.

Main Methods:

• Literature review of recent scientific publications on beer aroma and off-flavours.
• Identification of major aroma-active compounds (e.g., diacetyl, dimethyl sulphide, acetaldehyde, thiols).
• Compilation of a troubleshooting guide based on identified odour sources and chemical compounds.

Main Results:

• Detailed description of aroma-active compounds contributing to beer's sensory profile.
• Identification of common off-flavours and their associated chemical culprits.
• Established links between raw materials, processing, fermentation, packaging, and flavour stability.

Conclusions:

• Raw material composition, processing, fermentation, and packaging critically impact beer flavour stability.
• Specific volatile compounds are directly responsible for desirable aromas and undesirable off-flavours.
• This review provides actionable strategies for brewers to manage beer aroma and prevent defects.