Diacetyl Flavour Standard

What is Diacetyl Flavour?
Diacetyl is a naturally occurring compound formed during fermentation. It is characterised by its buttery, creamy, or butterscotch-like aroma and taste. While diacetyl can positively contribute to the flavour of some foods and beverages, such as butter and certain wines, it is often undesirable in beer and other products when present in high concentrations.

What Causes Diacetyl Off-Flavour?
Diacetyl is primarily formed during fermentation as an intermediate compound, alpha-acetolactate, produced by yeast or bacteria. When fermentation is poorly controlled, diacetyl levels can rise, leading to undesirable off-flavours.

Common Causes of Diacetyl Off-Flavour:

• 1. Fermentation Issues: Poor yeast health or incomplete fermentation can result in elevated diacetyl levels.
• 2. Bacterial Contamination: Certain bacteria, such as lactic acid bacteria, produce diacetyl as a byproduct.
• 3. Storage and Processing Conditions: Improper storage or handling of food and beverages can lead to the formation of diacetyl.

Using the Diacetyl Flavour Standard for Sensory Training
FlavorActiV’s Diacetyl Flavour Standard for sensory training allows brewers and food professionals to calibrate their senses:

• Train teams to detect diacetyl at very low concentrations.
• Maintain consistency in quality control assessments.
• Improve accuracy in flavour profiling and troubleshooting.

By incorporating FlavorActiV’s standard into sensory training programs, professionals can ensure reliable detection of both desirable and off-flavour levels of diacetyl.

How to Recognise Diacetyl Flavour: Sensory Terms
When using a diacetyl flavour standard, look for these key descriptors:

• Buttery – the classic diacetyl aroma
• Creamy – smooth, dairy-like notes
• Milky – subtle, soft aroma reminiscent of milk
• Butterscotch – sweet, caramel-like undertone

The sensory threshold for diacetyl is very low, typically between 10–40 ppb, making accurate detection critical for quality control in brewing and food production.

What are the Professional Applications of the Diacetyl Flavour Standard?
The Diacetyl Flavour Standard is widely used across industries to ensure product quality and consistency.

Key Applications:

• Breweries and Beverage Manufacturers – To detect and control diacetyl off-flavours caused by fermentation issues or bacterial contamination, ensuring a clean and desirable flavour profile.
• Food Manufacturing – Detect diacetyl contamination in dairy, butter, and fermented food products.
• Sensory Training – Train sensory panels to recognise, scale, and describe diacetyl’s buttery and butterscotch-like notes with accuracy.
• Quality Assurance – Maintain high standards in food and beverage manufacturing.

Other Information
Beer Flavour Wheel Number: 0620

Flavour Level: 8-600 μg

The sensory threshold for diacetyl, the classic buttery flavour, is very low, typically 10-40 ppb.

Recommended flavour standard / sensory reference standard of: American Society of Brewing Chemists (ASBC) and the European Brewing Chemists (EBC)

Each capsule is manufactured according to pharmaceutical standards at FlavorActiV’s GMP-certified Flavour Centre, located in the UK. This ensures consistency, stability, and industry-trusted quality.