Tesco is said to be selling unwashed potatoes in its stores for the first time since the 1970s.
Until the 1970s, most UK supermarkets and greengrocers sold unwashed potatoes. Leaving soil in place would help block out the light and slow down their natural decay.
Now Tesco is aiming for a return to traditional selling of potatoes, helping to reduce the waste advisory group WRAP, which according to the UK is the most wasted food in the UK.
The supermarket recently made an initial attempt to sell organic white potatoes in 120 stores with positive results and is now expanding the move to 262 stores.
The study is being carried out in collaboration with Branston, one of the UK’s largest potato suppliers based in Lincolnshire.
Rob Hooper, Technical Director of Tesco Produce, said, “Until about 50 years ago, potatoes were generally sold unwashed and a natural film of earth around them would help keep them fresher longer.
“By the late 1970s, supermarkets and greengrocers in general tended to sell more cosmetically perfect products. As a result, the potatoes were washed before being displayed.
“We ran an initial test in stores in the Bristol area last November to see how shoppers would react. It was a success. Now we are extending this test to the south of England.”
In previous tests, Tesco and Branston found that the shelf life of unwashed potatoes almost doubled and offered up to five days more freshness.
When potatoes are exposed to light, chlorophyll forms in their cells, which gradually turns the skin green.
Chlorophyll is the natural green pigment found in plant leaves and stems and is used along with solar energy to create the nutrients needed for growth.
Dominic Groom, Branston Technical Manager, said, “Working with Tesco, we identified a potential way to extend the shelf life of our organic potatoes by leaving them unwashed.
“The ground cover provides a protective layer against the impact of light on the greening skin. This is a factor that we consider when determining shelf life.
“This study should give us a clearer understanding of how this impact manifests itself and how customers rate the soil on their potatoes.”
Will McManus, WRAP fresh produce sector specialist, said, “One of the biggest drivers of potato waste in the home is that we don’t use it in a timely manner. So anything we can do to extend shelf life can really be important in the fight against food waste.
“We are delighted to see how Tesco is working with its suppliers to tackle food waste and bring changes to their shelves.
“Household food waste is a major contributor to global emissions, as 70 percent of food waste (post-farm gate) comes from the household.”