North Carolina grows more sweet potatoes than any other state, but due to the US Department of Agriculture’s strict grading policy, only the best sweet potatoes can be sold whole, while lower-quality potatoes are turned into other products.

Many don’t make the cut at all. Approximately 28.6 million kilogram of sweet potatoes are left to rot in North Carolina fields each year, according to Brett Taubman, director of the Fermentation Sciences Department at App State.

During his research, he realised he was missing a major opportunity.

“We were working with sweet potatoes, we were working with plant-based milks ... and it just kind of hit me, like, why is there no sweet potato milk yet?” Taubman said. “I did a quick search, and sure enough, there was no sweet potato milk. We decided to do a test run... and it turned out good enough the first time that we decided to roll with that.”

The project was still a long way from commercialisation until NCInnovation stepped in.

The company is partnering with regional grocery stores to conduct consumer testing on different versions of the milk while also developing new products like creamers and yogurts.

Roostii also plans to open a bulk processing facility in Eastern North Carolina to be closer to farmers and leverage its regional North Carolina branding.

“There’s nothing more North Carolina than a sweet potato,” Taubman said. “It’s something we definitely are very proud of, and something that we want to use and lean on