Masterton Olive Press Manager Bill Hay tells the story of how in the early days of the Olive Press, olive grove owners would arrive with their olives piled into crates the size of shopping baskets to be tipped by hand into the press and any olive oil produced would be carried away in plastic bottles.

Nowadays the olives are more likely to arrive stacked high in giant wooden bins piled high on the back of a truck. And they are so heavy that they need to be loaded by forklift into the giant metal vat.

The press is a good measure of how far the olive industry has come in the Wairarapa. This year the press put through 286 tons of fruit compared to 58 tons when records were first kept in 2002. As one of the biggest olive presses in the country, it’s also handled fruit from Hawkes Bay, Kapiti Coast, Gisborne and North Auckland.

“It’s great for the Wairarapa because although there are some Italian shareholders, it’s owned mainly by Wairarapa olive growers,” says Olive Press chairman Rod Lingard.

Almost all oil produced in New Zealand is extra virgin, so called because it’s pure olive oil, extracted from the fruit solely by mechanical means without the aid of heat or chemicals. In Roman times this was done with a stone press, today’s olive presses use centrifugal force to separate the oil.

It’s a noisy but fascinating process to watch the press at work. Olives are first weighed in their wooden bins, then lifted into the metal vat. The weighing is important as growers are charged for the weight of fruit put through the press rather than the amount of oil produced. Generally, Wairarapa olives produce a yield of somewhere around 17-19 per cent of olive oil.

Lovely Wairarapa Olives

The olives are shunted up a conveyer belt to a blower that will remove any twigs or leaves that might have been shaken off the tree along with the fruit. Bill reports that the most fastidious of olive growers will oversee the olives as they move up the conveyer belt, picking out any foreign material that could contaminate the oil.

The olives are then washed, crushed to a purple paste, then stirred for 20-30 minutes or so to help the tiny blobs of oil to join together. Centrifugal force then presses the oil out of the paste and it pours out of a steel tap, a vibrant neon green and smelling as fresh as spring grass. It’s perfectly edible at this stage but it still has sediment floating in it so it’s left to settle for a month or two before being decanted, bottled and labelled.

The settling period also allows the oil to develop more complex mellow and or fruity flavours, rather like wine being left to develop in a barrel. Also like wine, the flavour of olive oil varies from year to year depending on the weather. Different types of olives also produce different types of oil. Koroneiki, for instance, fast becoming one of the more popular varieties, produces an oil with a complex buttery flavour. Green unripe olives give an oil a grassy tang and are also rich in health-giving antioxidants, while ripe purple olives make a fruitier olive oil.

But not only olives go through the press, Bill also puts through lemon and limes for the flavoured oils produced by some of the groves. According to Bill, these don’t cause too many problems for the press, though being Italian-made, it generally copes better with the Tuscan olive varieties.

Work at the press begins with the first olive harvest at the end of May and it’s usually flat out until early August. For the rest of the year Bill works on local olive groves, pruning trees or doing any maintenance jobs.