The characteristics that indicate the poor quality of the olive oil can be:
• Bad smell. It’s a characteristic that demonstrates a faulty decantation or the contact with the water extracted from the fruits during the pressing.
• Fermented or Fusty flavour (a flavour that reminds the smell of an old olive oil press). It indicates that the olive took a long time to be processed and suffered high degrees of fermentation.
• Tasteless. It´s an olive oil which has not maintained its typical flavour or aroma. This may happen because of the mixing of products.
• Winey-vinegary-acid-sour. The taste resembles wine or vinegar; this is caused by the high presence of acetic acid and methanol as a consequence of the use of old olives and in process of deterioration when extracted.
• Rancid. The taste of oxidized fat indicates that the product has been exposed to air.
• Musty-humid. Olive oil attacked by mould when stored.
• Dirty/wastewater. This taste can be explained by the lack of cleanliness in the process of pressing the olives.
• Metallic. Metallic taste indicates that the olive oil has been in contact with metals for longer than necessary.