It is the world’s most expensive spice, commonly known as “red gold” for its prices that range from $40,000 to $50,000 per kg in New Zealand and up to $80,000 in Australia – and it is being harvested in Central Otago.

It’s now the height of the saffron harvest season, during which workers hand-pick the delicate lavender flowers of the Crocus sativus before the leaves are unfurled, and the stigma the saffron removed and dried.

Wendy King, who owns Wynyard Estate Saffron with her partner Graham Strong, says to produce one kilogram of saffron requires an average of 125,000 flowers.

She is clearly enchanted by the plant, which grows from a corm rather than a bulb, referring to it as “she” and giving it female characteristics.

The flowers need to be picked before they open, so the morning mist common in the Teviot Valley can be helpful on crisp autumn mornings, she says.

“Like most females, she doesn’t like coming out on cold mornings,” Ms King said.

Crocus sativus propagated by division, rather than setting seed, Ms King explained.

“No bee pollination required, no male required self-sufficient.”

Harvest and processing of the vibrant spice is labour-intensive, as not only must the flowers must be picked by hand, but the unfurling of the petals and removal of the stigma is also by hand.

I see red . . . The crocus plants are unfurled by hand and only the red part of the stigma is placed on racks for drying.

The saffron threads from Wynyard Estate are then sold in 0.5g, 1g or 2g weights for use in cooking, made into saffron-infused products or sent to Alaron Products in Nelson, where they are made into a supplement to support and maintain eye health.

The couple planted their first corms on their Ettrick property in 2012 and had their first harvest the following year, only reaching one kilogram of premium grade 1 saffron in the 2016 harvest. In 2017, they had enough saffron to start producing the eye supplement.

The business was first planned as a “retirement dream”, but she was glad they started it earlier as in the early years all the work was done by themselves, Ms King said.

“We wanted something where we could establish a little business in the natural health line.”

Dr Strong holds a PhD in botany from the University of Otago alongside further training at the University of California, Davis, and Ms King was a chef in the Royal New Zealand Air Force.

One of those who gave the couple advice when they were setting up their saffron business was Maurice Watson, of Bannockburn, who with his partner, Megan Huffadine, then owned Heart of the Desert Saffron.

Mr Watson said they grew saffron as a side business for 13 or 14 years from 2001, and it was a quirky and fun venture.

“We ran an informal saffron growers’ association and did a lot of educational things,” he said.

The business also provided material to researchers in Italy who were doing research on macular degeneration, which could lead to vision loss.

In her element . . . Wynyard Estate Saffron co-owner Wendy King’s enthusiasm for the business is evident.

Ms King said other research was done in the United States, the United Kingdom and Australia, with about nine clinical trials looking at the effects of saffron on eye health.

“We just had to follow the research,” she said.

There were more than 100 producers of saffron in New Zealand, she said, and the spice grown in New Zealand and Australia was termed an artisan product, of higher quality than that of some of the world’s larger suppliers, such as Iran.

Wynyard Estate’s saffron is the highest-quality sargol – an Iranian term that literally translates as “top of the flower”. This means there is no floral waste left on the bottom of the stigma.

Ms King showed a sample of her saffron threads beside an Iranian product labelled “100% pure”, in which you could see the lighter-coloured “waste” at the end of the threads.

Harvest lasted for six to eight weeks, with the boom phase in the mid three to four weeks, she said.

“The first couple of weeks are quite steady and building, then about the third week it goes mental,” Ms King said.

The “mother” corm produced eyes, like a potato, that each sent up a shoot which would flower. During the peak of the season, each shoot flowered daily.

The mother died at the end of the season, and her offshoots took her place. Ms King said they dug up and redistributed the new corms each second year, and had just under 2ha in production.

Despite its delicate flowers, it was a hardy corm, tolerant of most soils and lying dormant over summer, so not needing irrigation.

Proof of the pudding, as it were, for the quality of the saffron was that Wynyard Estate had several buyers in Iran.

“They love it,” she said.

“They’re excited by the quality.”