Cherie Bulley
Sherie Bulley — Olive Oil - Room 1, Saturday 8:30am
A HortResearch scientist from Auckland, Sherie is part of the Sensory and Consumer Science team that has developed a national olive oil tasting panel that is recognised internationally. There are many aspects to identifying ‘good oil’ and our speaker can explain how it all comes together.
The Olives New Zealand (ONZ) Sensory Panel is the sole group that certifies olive oils in New Zealand. The panel is made up of around 12 members who have been screened and received sufficient training in the sensory analysis of olive oil. The panel is led jointly by Margaret Edwards and Cynthia Lund, and is one of 35 panels worldwide that is currently accredited by the International Olive Oil Council (IOOC) for 2006 / 2007. Panels are required to pass 2 exams per year, as set by the IOOC, in order to retain accreditation status. The IOOC stipulate regulations in all areas of the testing. Some examples of regulations set by the IOOC include the dimensions and colour of the glass used for testing, the temperature of the oil, the amount of oil given to panellists and the assessment sheet for testing.
The panel came to be established when ONZ realised that New Zealand-produced olive oils were not going to be able to compete competitively in the commodity market. Given that the bulk of the market share in the commodity market is held by producers in Italy, Spain and Turkey, ONZ felt the best marketing strategy would be for New Zealand olive oils to compete in the boutique, high-quality sector. This would allow our oils to attain a premium price in the marketplace. What was also required was a means of giving consumers assurance that when they are buying a particular New Zealand olive oil, they are buying a quality product. ONZ recognised that the existence of a sensory panel to certify New Zealand olive oils would be crucial in their ability to meet this goal. As a result, the ONZ Sensory Panel at HortResearch was formed in 2003. After several years of training, the panel was finally recognised by the IOOC in 2005 and attained accreditation in 2006. Despite the fact that the olive industry in New Zealand is extremely young, New Zealand extra virgin olive oils are increasingly being held in high regard both here and overseas. Our oils have an advantage in the export market in that Northern Hemisphere oils are 6 months old when ours are available. The industry itself is growing steadily, with ONZ (to which 400 grower members belong) reporting an increase of 60% in olive oil production from 2004 to 2006.
Extra virgin olive oils are highly prized for two major reasons: the health components they contain, and their flavour. They contain antioxidants and high levels of monounsaturated fatty acids, both of which are known to have a positive effect on health. In terms of flavour, the positive attributes of extra virgin olive oils come under three main classifications: fruitiness, bitterness and pungency. Fruitiness is the sum of all the aroma and flavour characteristics, which could include attributes like ‘grassy’, ‘caramel’, ‘olive fruit’ and ‘tomato leaf’. Bitterness is perceived in the mouth only. Pungency is the hot, peppery or chilli feeling that is felt in the mouth and/or in the throat.
In New Zealand, the certification process begins with olive oil producers. It is not a mandatory process that every olive oil must complete, and producers pay for the privilege. Oils are sent away to be chemically tested by an approved laboratory, and also to HortResearch for sensory analysis by the ONZ panel. If the oil is successfully certified, the producer is provided with red ‘OliveMark’ stickers to place on their oils. Certification is completed annually, so producers who wish to retain certification status of their oil need to have their oils certified independently each year. Almost all olive oil made in New Zealand is produced with the purpose of being sold as ‘extra virgin’ To be certified as extra virgin by the ONZ Sensory Panel, an oil must be found by the panel to be free of any defects, and to have a fruitiness mean of above 2.5 (on a 10-point scale).
What causes an oil to have a defect? Various stages in the olive oil production chain can give rise to defects. Defects can occur at different stages of the olive fruit life cycle including pre- and post-harvest, as well as pre- and post- processing, and also during the storage of the oil. Some cooler parts of New Zealand are prone to frost, and this has a large detrimental effect on the olives - a defect the panel term “frosted”. In some European countries where it can be extremely humid, olives may be left in piles prior to pressing, leading to the growth of fungi and yeasts. This leads to a defect called “musty”. The battle to prevent defects does not end with the bottling of the olive oil. Rancidity is the most common defect of all, and exposure to light, oxygen and heat are the primary promoters of this defect. Therefore, the way that olive oil is stored can have a large impact on its quality. Over time all oils will eventually become rancid independent of any other factors, but ensuring that oils are stored appropriately will help to extend their shelf-life. While extra virgin is the highest grade of olive oil, there are two lesser grades — virgin and lampante. Both virgin and lampante are grades of olive oil that, like extra virgin, are classified as such through both chemical and sensory analysis. In terms of sensory analysis, to be classified as ‘virgin’ an oil needs to have a mean of defect between 0 and 6.0, plus it requires a mean of fruitiness above 0. For an oil to be classified as ‘lampante’, it needs to have a defect with a mean of at least 6.0.
Besides extra virgin, there are a number of other types of olive oils on supermarket shelves. These oils tend to be refined oils, and therefore devoid of the nutritional benefits that real extra virgin olive oils provide. ‘Pure’ olive oil is low quality olive oil (either virgin or lampante) that has been refined to remove defects. ‘Light’ olive oil is generally a mixture of refined and virgin oils. The term ‘light’ simply refers to the lightness of flavour — it is not light in fat or calories or colour.
The majority of extra virgin olive oils produced in New Zealand are blends. That is, the oil from 2 or more olive varietals are blended together. Typically blending is done to ensure complexity of the resulting oil. By adding complexity we mean that it gives a broader range of flavours to the oil. Different varietals contribute different flavour characteristics to an oil, and the ripeness of the fruit will also have an impact. Blending is often carried out to ensure the positive attributes in the oil are balanced also. For example, if a single varietal oil is very fruity, but the bitterness is low, blending can allow a producer to increase the bitterness by adding oil from a different varietal. Some producers even choose to blend 4 or 5 varietals together. Being able to produce a good single varietal oil takes skill as there is no relying on multiple varietals to give complexity to the oil. Complexity can only be gained through harvesting and pressing fruit at various stages of maturity.
What do you need to look for when buying an extra virgin olive oil? There are a few things you can look for to help prevent yourself from making an expensive mistake. Look for oils kept in dark glass bottles. These are less likely to be rancid as less light is able to enter and affect the oil. Avoid oils that are stored under bright lighting. Buy your oil in small quantities, as the greater the surface area that is exposed to air, the faster the oil will become rancid. All New Zealand extra virgin olive oils will have a pressing date on them, so this will guide you in buying the freshest oil. Look after your oils by storing them in the refrigerator when you get home — this is the safest place for them. Most importantly, look for oils with the red ‘OliveMark’ sticker. You can trust that these oils are of the highest quality, since each one has been through the stringent process of certification.
For more information, visit the official Olives New Zealand website: www.olivesnz.org.nz
Cherie Bulley is a member of the Olives New Zealand (ONZ) Sensory Panel, and is involved in the certification of olive oil as being of extra virgin status. The panel is based at HortResearch’s Sensory and Consumer Science Facility, where she is employed as a sensory and consumer researcher. Email