Solvent

• The composition of specific colognes are considered trade secrets, but the major component of cologne is the solvent, usually ethanol, that holds the aromatic compounds.
  
  

Chypre

• A common component in colognes is chypre that is developed using scents derived from bergamot, oak moss and patchouli.
  
  

Citrus

• Citrus scents from oranges, lemons and limes are a common component of colognes. Citrus paired with chypre is sometimes considered to be a type of cologne.
  
  

Wood

• For masculine scents, wood is a common aromatic source. Sandalwood, birch and pine are popular types of wood for cologne scents.
  
  

Leather

• Leather is a type of scent used in perfumes, though it is not derived from actual leather. Leather scents are derived from honey, tobacco and even wood. Whether leather can be considered a true cologne scent or not is debatable, though fragrances employing leather scents are common among those purchased by men.