A stack of ReToast's toast-shaped cookies.

Minnesota students’ snack innovation fights food waste and climate change

Food waste is a major problem in the United States, with about one-third (30%-40%) of the country’s food supply becoming waste, according to USDA 2010 estimates. That’s about 133 billion pounds of food worth $161 billion thrown away, wasting the energy, water, and other resources used to produce it and creating emissions during product transportation and processing.

Bread is the most wasted food product in the U.S., often discarded when it is still edible but simply past peak freshness. Students at the University of Minnesota developed ReToast, a cookie in the shape of toast that is made from at least 30% upcycled food products, such as bread, that would otherwise be wasted.

The innovation

A photoillustration compares wheat roots to those of Kernza wheatgrass in four seasons; the roots of the perennial Kernza plant grow significantly deeper than those of the annual wheat.
The roots of the perennial Kernza plant grow significantly deeper than those of annual wheat, helping to reduce erosion, among other benefits. Credit: Jerry Glover / Wikimedia Commons

The flour used for ReToast contains about 64% toasted bread scraps, 22% spent grain from brewing beer, and 15% spent Kernza — a perennial, non-genetically modified grain trademarked by the Land Institute that shows promise in fighting climate change.

Kernza is a hybrid wheatgrass originating in Eurasia. It was first used in the U.S. as animal feed but within the last decade has been bred for human consumption. It is increasingly used for carbon sequestration. 

Much of the magic lies in the plant’s roots, which can grow up to 10 feet deep. Instead of depleting soil of nutrients and requiring fertilizer like many other crops, Kernza actually delivers rich organic matter to the soil. It increases carbon sequestering, reduces erosion, and decreases the amount of energy and pesticides needed for farming, according to University of Minnesota and USDA research.

“We collected leftover bread scraps from local Twin Cities bakeries and developed our own self-curated quality process to make sure it is safe and ready to be used as a functional, nutritive ingredient for baking,” team lead Radhika Bharathi said in a news release. Bharathi is a Ph.D. student whose research focus includes optimizing processing strategies to improve Kernza flour. “I wanted to make sure that we incorporated Kernza in our formulation because it fits so well in the theme of using sustainably sourced ingredients to develop ReToast.” 


ReToast won first place in the American Society of Baking’s Product Development Competition in February. This year’s competition centered on sustainability. Students on the ReToast team received scholarships for the achievement. 

What’s next

The ReToast team is having conversations with investors, and they hope to commercialize their product soon. 

“It is important to apply technical skills learned in a classroom to solve real-world problems such as food waste and climate change; only then can we move towards making a positive change in society,” Bharathi said.

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