By Mark Dymiotis
Letter to the Editor
The Australian olive and olive oil industry is young and risky. Learning from the experience of traditional olive-growing countries is important for successful and sustainable production and promotion of olive products. The large population of Italian, Greek and other migrant people from Mediterranean countries could provide valuable information essential to the Australian olive industry.
Such knowledge is missing from the article “The olive: fruity, hardy and extremely civilized”, The Age, May 5, 2001.
The “kalamata” cultivar has been listed as a table variety and “manzanillo” as a dual-purpose i.e. suitable for oil production and for table olives. The reverse is true. The “kalamata” is a dual-purpose variety and contrary to perceptions is suitable for all three types of table olives: green, black firm and shrivelled. “Manzanillo’s” oil yield is low, and in Spain, where this cultivar originated, it is used exclusively for table olives.
The article also appears to be unclear about fruit ripeness. Olives are ripe only when the colour change of the olive flesh reaches the stone – not when the skin becomes shiny black. Another definition of ripeness could be when the olives shrivel naturally on the tree.
The recommendation to “knock the fruit off with sticks”, although traditional, is inappropriate. Apart from bruising the fruit, there is considerable damage to the young shoots that are the following year’s fruit bearers. Hand harvesting is the best option for backyard producers but mechanical harvesting is the only viable option for larger producers.
Also, the recommendation to eat the smaller fruit straight from the tree when they are over-ripe and starting to shrivel is applicable only to masochists! Even after the olives shrivel completely and fall off the tree they are still too bitter to be eaten without processing. There is only one exception. The Greek cultivar Thrubolea (Olea europaea media oblonga) is the only one where the bitterness of the olives is lost when they shrivel – but not always.
The information given on how to process table olives (repeated soaking in caustic soda solution, in water and in weak brine) is unnecessarily complex and risky. The use of caustic soda is a modern industrial method, which often compromises flavour of the olives.
With the repeated soakings there is an increased risk of leaching sugars out of the olives – thus preventing the highly desirable lactic acid fermentation of green olives which is essential for improved flavour and better preservation of the olives.
The traditional processing method, which has stood the test of time, is very simple. Green or black firm olives are placed in a brine solution of about 10 % strength (nine parts in weight of water to one part salt). The olives will be ready in a few weeks to a few months – depending on the stage of maturation, the size of the olives and whether the olives have been slashed or crushed.
The article recommends combining olive oil, herbs and spices. This is a modern preoccupation. If needed, the dressing ingredients are added when serving the olives. Traditionally, olives were on the table, plain, without any additions, to accompany vegetarian dishes. Eaten like this, olives act as a flavour enhancing ingredient.
From: The Age – Gardening, Saturday, 5 May 2001 – with amendments.