In front of me are olive oils from adjoining fields, Atutahi, Molive and Left Field, plus a blend of the trio called Three Fields.
The Molive samples are fresh off the press, "a whole week old", says Cooper. One is nearly dark green, and the strength is almost too strong for me ... almost.
Cooper explains Three Fields was formed in 2000 and began commercially producing in 2004, hitting Best in Show at a national competition immediately.
"It was somewhat premature," he laments. "We only had 50 litres of oil."
Since then it has won 33 awards and five international awards - although entering internationally has its problems.
"We have terrible trouble meeting their deadlines, because we are a winter crop."
All three groves have won awards in their own right. They all taste great, although the newest off the press have a bitter edge. Mrs Graham explains olive oils ideally need to sit for six weeks, perhaps for two months.
"It does mellow, quite definitely. I find the oil is at its premium after six months. Certified extra virgin is guaranteed for two years."
I sample an Atutahi from last season, which had a bad, wet summer. The taste is considerably milder, but still delicious.
With me is Sue McLeary, who is organising the Olive Festival for the Martinborough Business Association. She's just come from a coffee and scone with me and a catch-up with Martinborough Rotary, which is lending a hand with the marquees in the town square for the night market on Saturday.
She's also just organised 200m of fairy lights.
Ticketholders for the Olive Festival will enjoy visits to groves for tours of the operations, to see how olive oil is made, but the night market is open for everyone, providing an substantial evening hit of crafts, fashion, art and food.
She says about 65 stallholders will be at the market, running from 4.30pm to 8.30pm.
"Festival ticketholders start with a series of lunches, choosing between six venues around the town, who have partnered with local olive groves. They will have a menu with an olive theme. People choose which lunch venue, and after that, they are free to roam."
Readings, olive lectures workshops and master classes are on offer, fronted by international olive oil judge Margaret Edwards. Six olive groves are open for tours.
"Olivio, who specialise in infused oils, will have soups to try, and people can choose what olive oil to sprinkle in. Does fennel work best? Or paprika?"
Harvesting activities will be shown, including "shakers" which shake trees every 10 minutes.
Ms McLeary expects the festival to become an annual event at a normally quiet time of year.
"This is something that's a bit of fun. It's celebrating Martinborough's number two gourmet crop."
See www.martinborougholivefestival.co.nz for more information or tickets.