Acetaldehyde is the predominant one aldehydein all wines. It arises whenalcoholoxidized to acetic acid. It is mainly found in sherry in higher concentrations. In wines that are not fortified with alcohol, a small dose can enrich the aroma; however, too high concentrations of aldehyde are regarded as a fault. The smell of acetaldehyde is reminiscent ofApple peel, Almonds, hazelnuts, straw and Dried fruits.