Not all Olive Oils are created equal!

Olive Oil classifications

The chemical assessment of olive oil is classified according to the level of Free Fatty Acid present and the Peroxide Value of the oil.

  • Extra Virgin Olive Oil contains no more than 0.8% acidity according to the IOC (International Olive Council) and 0.5% according to Olives NZ. The Peroxide Value should have a reading of less or equal to 20mEq according to the IOC and 15mEq according to Olives NZ.

Acidity is a measure of quality and freshness of the olives and the pressing procedure and the peroxide value measures oxidation, which increases in value if the oil is not stored correctly or as the oil ages. Fresh is definitely best!

Olive Oil does not improve with age but starts to degrade from the moment it is pressed. The rate of deterioration is slow at first and depends on how well made the oil is and how it is stored.

There are two phases of deterioration. Firstly oxygen attaches to the fat molecules to produce hyperoxides. These are odourless and tasteless but in time they break down to produce rancidity – a disagreeable taste and smell. Extra Virgin Olive Oil is best used within 2 years from pressing albeit the robustness of New Zealand Oil means that it can age considerably longer than this before rancidity sets in.

Light and heat are the catalysts that accelerate oxidation of oil. We store our oil in stainless steel containers in an insulated room blanketed in the completely inert gas – Argon.

We bottle our oil in dark glass with a squirt of argon to further preserve its freshness

There are 3 Internationally recognized grades of Virgin Olive Oil based upon their acidity, Extra Virgin ( less than 0.8 %), Virgin (0.8 -2%) and Lampante Oil ( greater than 2% -indicating  historically it was not for consumption but for lighting).

Pure and lite olive oils… beware!

An even lesser quality is that of Refined Oil. There is nothing refined about “Refined Oil”. It has been chemically cleaned to eradicate excessive acidity, oxidisation or unpleasant taste. It comes under a guise of names, often confusing. Olive Oil is usually a blend of low grade Virgin and Refined Oil. Some of its acidity may not be more than 0.3% but chemical extraction from poor quality fruit  or from the waste of first pressed fruit is not worthy of serious consideration – no taste to speak of. Terms such as Pure or Lite are just marketing terms to deflect from the rather unfriendly and somewhat unpleasant description and process of chemical extraction – the term solvent albeit correct sounds even more unsavoury

Neudorf Olives, Upper Moutere Nelson