Atypical flavor production

The microbiology of "atypical flavor" production in brewing—an overview... 

This table forms a key part of instruction for sensory evaluation programs in general and specifically for fiavors associated with atypical fermentation activities of bacteria and or wild yeast. The data in the table represent summaries of information obtained from many of the references cited in the text, product summaries from suppliers of sensory standards (specifically Flavor Activ) and collected notes of the authors over many years and so, for clarity, not all specific points are referenced in the table itself. 

As a group, the organic acids impart a sharp, sour taste to a product. The di-and tri-carboxyhc acids are of particular value in this respect as they occur naturally in many fruits. These compounds are odorless and are not used directly in flavoring formulations, but citric, malic, and tartaric acids are often used in end products to improve and even enhance added fruit flavorings which would otherwise be atypical of the natural finit... 

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