1.2. Smoky off-flavours

Contamination by smoke from wood fires or other sources during drying or storage causes a characteristic smoky off-flavour in cocoa mass and chocolate. This is another off-flavour which cannot be removed during chocolate manufacture. 

The presence of smoky beans in a sample may be detected by crushing some beans in the hand, or preferably in a mortar, and sniffing them. This is a quick test but it is not as reliable as cocoa mass tasting or making up samples of chocolate on a small scale. 

A smoky off-flavour is sometimes described as “hammy” because it is reminiscent of smoke-cured bacon. Hammy off-flavours can also arise from over-fermentation although it is quite easy to distinguish between the two defects. 

In smoke contaminated beans the hammy note is dominant. In over- fermented cocoa it occurs as a minor note against a putrid, ammoniacal or occasionally soapy/phenolic background. 

The presence of phenols, such as guaiacol, is probably common to both smoke contaminated and over-fermented cocoas. The off-flavour can be prevented by ensuring proper fermentation and avoiding contact with all sources of smoke contamination during drying and storage.

Preventing exposure to smoke will also reduce contamination of the cocoa by mineral oil hydrocarbons (MOSH/MOAH) and polycyclic aromatic hydrocarbons (PAH) which are a food safety concern (See 2.7 Mineral oil hydrocarbons and 2.8 Polycyclic Aromatic Hydrocarbons for further details).