"We wanted to move out of town and play on the land, and we wanted to be feeding ourselves as well," Mr Anderson said.
They started planting olives in September 2000, after hearing a National Radio programme about artist Mike Ponder's olive-growing exploits.
The planting continued over five years. They've settled on the Italian leccino, pendolino and leccio del corno varieties because their fruit ripens early, before frost hits. Frost affects the taste of the fruit, and frosted olives will not make a top quality oil.
The trees need heavy pruning. The Andersons also mow parts of their orchard and spray the leaves of the trees with a liquid fish fertiliser.
They don't have many problems with disease. And birds, which can take an entire crop, leave theirs alone because they prefer the figs, grapes and apples ripening in the Andersons' extensive orchards at the same time.
The couple got their first crop in three years, and had enough olives to press into oil in four to five years. Their biggest harvest so far has been three tonnes.
Between them, they can strip pick 300kg of olives from their trees in a day, all "peasant labour". But Mrs Anderson said it was pleasant work and friends and family sometimes helped.
It takes 10kg to 12kg of their olives to make a litre of oil - a largeish amount. But Mr Anderson said the oil content of olives varies and can be 16 to 18 per cent if the fruit is fully ripe. In Italy, growers can get up to 22 per cent from their fruit.
At first the Andersons took their crop to Otaki or Feilding for pressing. But if olives are not pressed within 24 hours, the oil has a musty taste. Not having their own press meant the Andersons were at the mercy of others to press the fruit promptly.
So they bought their own press, the smallest on the market. It processes 50kg of fruit an hour. The combined cost of the press, an elevator to feed it and a shed to put it in was $80,000 - a big expense for a small operation, but they don't regret it.
"We work hard for our money and that's how we choose to spend it. It gives us pleasure and it gives others pleasure as well," Mrs Anderson said.
There are now a lot of olives grown in the wider region. Growers from Mangamahu, Kauangaroa and Lismore bring their fruit to the Anderson's press, and a grower from Papaiti ferries his crop across the river in a boat.
The Andersons' press works centrifugally, crushing fruit and stone.
The olives they press are one third green, one third half ripe and one third black, with some picked early to beat the frosts.
Waste from the press is composted. A possibility is drying it into firebricks, as is done in Italy.
