Olives – Processing

Poor olives. They must be very confused. For thousands of years, they were on the table in a supportive role. Now they find themselves on formal tables, in cocktails and are even served stuffed.

Traditionally, olives were a food of the underprivileged. As with bread, they were on the table and people could help themselves. As with fetta cheese, the addition of olives to the Greek salad, although in line with the principles of the traditional diet, is a restaurant tradition.

Olives keep very well and are easy to carry when travelling – which I always do. Eaten with good bread (old-style bread, not the modern spongy version) and fresh vegetables they provide a simple, satisfying and nutritious meal.

Straight from the tree, olives are bitter. Traditionally, this bitterness was removed with the use of salt or brine. In recent years, the debittering of green olives – by the olive industry – is usually done with lye (caustic soda). There are three main types of processing: The American style, where green or turning-colour olives are processed with lye and turned black artificially; the Spanish style, where lye is used for the debittering of green olives but the olives retain their natural colour; and the Greek style, which involves the use of salt with the olives maintaining their natural colour.

Green olives are harvested when the colour of the skin has changed from a leafy green to a bright or yellow green. Black olives are those left on the tree until the colour of the skin has changed to black and the colour change of the flesh has reached at least halfway to the stone. Eventually, if left long enough on the tree the colour change will reach the stone and the olives of some varieties will become shrivelled. The more mature the olives, the quicker they lose their bitterness.

Depending on the variety and the region where the olives are grown, green and black olives, in Australia, are available from March to June, or even later. The shrivelled type is available later in the season – from June up to August, or even September.

Note that the maturation process of olives is notoriously variable – even on the same tree – and it is unlikely that all the olives will reach the same degree of maturation.

Processing fresh olives
After harvesting or purchasing fresh olives, discard any damaged ones and wash well. While placing the olives in water prior to debittering for a few days and changing the water daily will speed up the debittering, it risks compromising flavour and storage life. For green olives, there is real possibility that the changing of water will risk losing the natural sugars of the olives thus depriving the highly desirable lactic acid fermentation. For the black shrivelled type (see below), avoid lengthy washing because the olives will absorb water.

The debittering methods given below follow the salt treatment method, a natural method that produces olives with better organoleptic qualities (flavour, taste and smell). Traditionally, the brine is prepared by dissolving salt in water until a fresh egg floats and the exposed part is the size of a 10-cent coin. Nowadays the brine is about 10% i.e. for 9 lt water you use 1kg salt.A good sealing of the jars is essential for succesful results.

Green olives
For crushed green olives, select olives which have just changed colour from a leafy green to a bright green. Crush them by hitting them with a solid object. In order to avoid discolouring, as soon as the olives are crushed, place them in water. Squeezing one or two lemons into the water will keep the olives shiny. A better and more simple way is to place them straight into the brine.

Place the olives in jars and fill up with brine. To prevent parts of olives floating, wedge lemon slices or dill stems under the neck of the jars or place an appropriately sized plate or piece of wood on top. The olives will be ready in about four to six weeks – longer if they are at the green stage that is preferable, shorter if yelow-green.

For slashed green olives, make two or three slashes to the stone on each olive and place in brine as above. These olives will take longer to lose their bitterness.

For whole green olives, place them into the brine as above and exercise great patience. They will take a lot longer to be ready – five months and longer.

As a general rule the larger the olives and the less mature they are, the longer they will take to lose their bitterness.

One way to use green olives after debittering, especially the crushed ones, is to season them with crushed coriander seeds, diced garlic, parsley, lemon and a little virgin olive oil. These olives are very appetising and are suitable for a light meal with bread, olives and tomatoes or cucumbers or other suitable vegetables.

Firm black
For this type of olives you need large, firm, fleshy, black olives. For best results the colour change should reach at least half-way to the stone. After washing, place them directly into jars and fill with brine. The olives will take at least three months to be ready. Depending on preference, vinegar can be added to the brine – not necessarily at the beginning. These olives are best without seasoning. They can accompany non-animal food.

Black shrivelled
Wash the olives quickly, so that they do not absorb water, drain them and allow to dry – preferably in the sun – for a day or longer. Place them in a box (with holes on the bottom and the sides) in layers of about six to eight centimetres, with plenty of rock or unprocessed sea salt between each layer. The quantity of salt should be very generous. Place a heavy object (20 kilograms or more) on top of the olives to speed up the draining and, with it, the debittering process. Turn the olives every one or two days, making sure the salt is spread around the olives. If a box is not available, a hessian bag can be used.

The olives will be ready very soon – in about two to three weeks. Remove the salt by tossing the olives in a large bowl or by rolling them in a cotton table cloth, but do not wash them. Store in a dry, cool place. Because of their low water content, shrivelled olives can be frozen – the best way of storing these olives.

Shrivelled olives are a Greek favourite and are eaten without seasoning. An optional seasoning is to add very small quantities of crushed garlic, olive oil and oregano and toss them well until all the olives get a shine.

From: The Age, Tuesday, April 30, 2002 – with amendments.

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