It has been more than 50 years since major UK retailers have sold unwashed potatoes in their stores, but Tesco says it is giving it a go again to help cut down on food waste in the home.

Tesco says leaving the dirt on them can help potentially double their shelf life. According to advisory group WRAP, potatoes are the No. 1 items that are discarded before they are used. Bread, milk and prepared meals are all high on the list, along with carrots.

So Tesco is teaming up with supplier Branson with organic white potatoes on a trial to give customers added flexibility and convenience. It began in 120 stores, but the retailer says it will be featuring them in 142 more.

“One of the biggest drivers of potato waste in the home is that we don’t use them in time, so anything that we can do to extend shelf life has the potential to be really important in the fight against food waste,” said Will McManus, WRAP’s sector specialist for fresh produce.

“We are very pleased to see how Tesco are collaborating with their suppliers to tackle food waste and bring change to their shelves. Wasting household food makes a huge contribution to global emissions, with 70 percent of food waste coming from the home.”

In early trials, shelf life was close to an added five days of freshness.

“Last November we ran an initial trial at stores in Bristol and the surrounding areas to see how shoppers would respond and it was a success, so now we are widening this trial across the south of England,” said Rob Hooper, lead technical manager at Tesco.

Unwashed potatoes have the added benefit of preventing chlorophyll and energy that boost nutrients within the cells from quickly affecting the color of the skin. Though the response has been positive so far, it remains to be seen how customers will respond en masse.

“Soil coverage can offer a layer of protection from the impact light can have on the skin turning green, which is a factor we consider when determining shelf-life,” said Branston technical manager Dominic Groom. “This trial should provide us with a clearer understanding of how this impact manifests and how customers feel about soil on their potatoes.”