Our tasting

You can pay top dollar for extra-virgin olive oil. But the best indicator of a good oil is freshness - the top oils in our tasting were pressed this year.

Extra-virgin olive oil is produced without heat or chemicals. The International Olive Council (IOC) says that extra-virgin oil must meet certain analytical criteria and be free of defects when the oil is tasted by a sensory panel trained to IOC standards.

We were looking for well-balanced oils that had good aroma and flavour - and no defects. Colour has nothing to do with the quality of olive oil. Oils are tasted in blue glasses so the colour is masked.

We were disappointed in the overall results. Too many oils (mainly imported) fell into the "unacceptable" category when tasted. Retailers and importers need to do a better job of packaging and displaying extra-virgin olive oil.

Packing it in clear bottles and exposing it to artificial light for long periods will only result in the oil deteriorating.

Extra-virgin olive oil is an expensive semi-luxury product. It should be looked-after better so that consumers receive the quality product they're paying for.

Kiwi oils come out top

All the oils passed the chemical analysis we put them through, but there was a wide range in their sensory quality.

Fresh is best! The three top oils in our tasting were pressed in May or June 2008.

The Peta Mathias (pictured), Olivo and The Village Press Frantoio oils all had the qualities our judges were looking for - good aromas with lots of olive fruity flavours. They were also well balanced.

These three oils were also in dark bottles, which are better protected from the light. Clear bottles are a problem, especially in supermarkets where the oils sit under fluorescent lights. Some supermarkets are open for 24 hours and this increases the light-exposure.

The Borges, Pams and Paul Holmes Leccino oils were also very good. But the Borges and Pams had no date marking. We may have struck a fresh batch of these but there's no way of knowing - and other Borges and Pams on shop shelves may be older.

Tired oils

The most common complaint about the unacceptable oils was that they were tired. Tired oils taste "old" and not fresh - it's a sign an oil is starting to go rancid. But many oils don't give you enough information on the labels to judge.

Most oils state a best-before date, although that's no guarantee of quality. Many of the unacceptable oils were well within their best-before date. Colonna, La Espanola and Mas Portell Arbequina were judged unacceptable even though they had best-before dates in 2010 - that's over a year away.

The problem with best-before dates is you don't know how old the oil is. Six oils stated their pressed-on date. This is more helpful because you know exactly how old the oil is. We'd like to see pressed-on dates for all extra-virgin olive oil.

Some oils didn't do as well as they did in our 2006 tasting. Kapiti was one of our top oils in 2006 but this time our panel rated it poorly. The producers are concerned that their oil isn't being stored properly in shops and is following up this issue with retailers.

Ravida also got a lower rating. The importer told us the size of Ravida shipments has been reduced to ensure a fresher product in New Zealand.

Our tasting panel

• Margaret Edwards (senior judge) - Vice President of Olives NZ. Leader of the Olives New Zealand tasting panel.
• Franca Camurati (senior judge) - Chemistry consultant and judge for the International Olive Council. International olive oil judge. For seven years panel leader of the Italian Institute for Fats and Oils tasting panel.
• Roberto Zecca (senior judge) - International olive oil judge. Former President of California Olive Oil Council. Former panel leader of California IOC panel. Olive oil producer in Tuscany and California.
• Laurence Eyres - Chairman of the New Zealand Institute of Chemistry Oils and Fats Specialist Group. Business Development Manager, Food and Nutrition, University of Auckland. Food Standards Australia New Zealand board member.
• John Follas - A food and wine importer. Owner of specialist food store Truffle.

Consumer tastings differ from industry tastings and competitions. We buy our oil from shops just like consumers do - most other tastings and awards use oil supplied by manufacturers or importers. Our panel members tasted the oils "blind".

With a panel of five judges it's difficult to get consistent ratings. If one judge gives a low score this affects the overall score. For our tasting we only counted the scores of the three senior judges. Our three senior judges have all been trained to IOC standards.

In some cases we may have bought old stock or oils that hadn't been stored properly. Either of these reasons may account for the poor rating our panel gave some oils.