The former nurse and her husband, who have lived in the Far North for the past six years, milk their own East Friesian sheep from September to March.
They started with goats before switching to less-demanding sheep, building up the herd to the point where they had to do something with the milk.
"I spent the next three years learning how to make cheese and reading everything I could. There was a lot of trial and error and an awful lot went to the hens. I'm very particular."
In fact, Ms Oakley is so particular she almost had to be coerced to sell her cheese, let alone enter the competition.
Fellow cheesemaker George Houry, who moved to Kerikeri from Cyprus 10 years ago, met the couple when he was looking for sheep's milk to make the halloumi he missed from his homeland.
Ms Oakley was still unsure whether her cheese was good enough so Mr Houry organised a tasting session.
"It blew my socks off. I said, 'We have to get it out there.' It's far better than anything else and, even in Kerikeri, no one knows about it," he said.
Ms Oakley joined the Specialist Cheese Association, which runs the awards, and got in touch with cheese writer Jean Mansfield, who pushed her to enter and accepted the prize on her behalf.
So far her cheese, which is only in its second year of serious production, is available via a Ponsonby cheesemonger, Kerikeri restaurant Food at Wharepuke, and on-farm sales.
Despite the accolade Ms Oakley said she was not planning any changes. Just Ewe would remain a low-volume, high-quality operation.
Mr Houry's family recipe halloumi, also made under the Just Ewe banner, won a bronze medal.
He only started making cheese seriously when his daughter, Lilly-Marie, 12, wanted to hold a halloumi stall at a school market day.
Mahoe Farmhouse Cheese, at Oromahoe, south of Kerikeri, won a swag of medals for its yoghurts and Dutch-style cheeses.
The other major awards went to Waikato-based Dutch cheesemakers Meyer Gouda Cheese and Mercer Cheese.
The Northland winners in this year's NZ Champions of Cheese Awards are ...
Champion cheesemaker: Catherine Oakley (Winsam Farm, Kerikeri).
Champion soft white rind cheese: Grinning Gecko Brie (Grinning Gecko Cheese Co, Whangarei).
Champion sheep cheese: Just Ewe Winsam Farmhouse (Winsam Farm, Kerikeri).
Aspiring cheese maker: Zev Kaka-Holtz (Grinning Gecko Cheese Co, Whangarei).
Gold medals: Grinning Gecko Brie (Grinning Gecko Cheese Co, Whangarei); Just Ewe Winsam Farmhouse (Winsam Farm, Kerikeri).
Silver medal: Cumin Gouda (Mahoe Farmhouse Cheese, Oromahoe).
Bronze medals: Natural Yoghurt, Greek Yoghurt, Very Old Gouda, Edam, Gouda (all Mahoe Farmhouse Cheese, Oromahoe); Just Ewe Winsam Cheddar (Winsam Farm, Kerikeri); Just Ewe Halloumi (George's Cheeses. Kerikeri).