Three Countdown supermarkets will go plastic free in a 10-week trial to test what can be done to further reduce plastic in its produce section.

From February 10, shoppers at Countdown Orewa, Ponsonby and Manukau will be involved in the new "unwrapped" test in its fruit and vege section, which will see 65 items without plastic.

Countdown's general manager corporate affairs, safety and sustainability, Kiri Hannifin, said the trial will see more than a tonne of plastic removed from the stores, as well as brand new specially designed paper and cardboard packaging used.

Just lettuce and bagged herb portions will remain in plastic, as there were currently no sustainable alternatives.

Customers will be encouraged to use reusable bags in the trial and paper bags will replace plastic for bulk foods.

The company has invested more than $500,000 in shelving, packaging and production changes for the test, but it was an investment that had to be made if they were serious about reducing the use of plastic in the future, Hannifin said.

"Like all Kiwis, we are incredibly passionate about the environment and reducing the amount of plastic and packaging in our produce section is something we, along with our customers, are keen to see," she said.

"Unwrapped gives us a chance to give some new things a go with our growers and packhouses. We're really excited about how these stores will look and feel for our customers and team."

The supermarket giant wanted to test whether the changes could be sustained over the long-term and in a way that delivered better outcomes for the environment in Aotearoa.

"We're mindful that packaging or process changes might cause bigger issues, so we need to understand this a lot better before we roll something out nationwide.

"For example, without packaging some products might deteriorate far faster, causing food waste - that's something we absolutely want to avoid because of the detrimental impact food waste can have on the environment.

"We don't want to replace one issue with another and as such we need to monitor food waste very closely," Hannifin said.

However, any changes that were made needed to be easy and convenient for shoppers and better for the environment.

"Unwrapped will change the way our customers shop for 10 weeks, but their feedback could have a long-lasting impact on how all New Zealanders shop in the future and help guide our next steps."

During the 10-week test, Countdown would talk to customers and its own team to understand opinions on the changes, as well as measuring a range of factors.

"While some products, such as bagged lettuce and herb portions, will remain in plastic due to a lack of suitable alternatives, where possible any plastic packaging provided is made from PET or rPET, which can be recycled and used over and over again.

"Soft plastics can also be recycled at each of the Unwrapped stores."

Countdown phased out single-use plastic shopping bags in October 2018, and removed 150 tonnes of plastic from produce and introduced BYO containers nationwide.