section_path: Distilled beverages/Congeners
section_name: Congeners
paragraph_text: Congeners
  
  In the alcoholic drinks industry, congeners are substances produced during fermentation. These substances include small amounts of chemicals such as occasionally desired alcohols, like propanol and 3-methyl-1-butanol, as well as compounds that are never desired such as acetone, acetaldehyde and glycols. Congeners are responsible for most of the taste and aroma of distilled alcoholic drinks and contribute to the taste of non-distilled drinks. It has been suggested that these substances contribute to the symptoms of a hangover. Tannins are congeners found in wine in the presence of phenolic compounds. Wine tannins add bitterness, have a drying sensation, taste herbaceous, and are often described as astringent. Wine tannins add balance, complexity, structure and make a wine last longer, so they play an important role in the aging of wine.