WSU Tri-Cities students learn to repurpose wine waste

By Maegan Murray, WSU Tri-Cities

mixing-compost-at-wine-centerRICHLAND, Wash. – Students in linked biology and chemistry courses worked with the Wine Science Center this semester to test “recipes” for composting wine pomace – the grape skins, stems and seeds left over from winemaking. The Washington State University Tri-Cities classes will assess and compare results in the next few weeks.

What they learned can be applied to composting at home, as well.

“The highest percentage of food waste occurs in the home,” said Gretchen Graber, a WSU Tri-Cities horticulture labs instructor who helped set up the project. “Home composting can reduce the amount of organic matter going to landfills. Composting is a good do-it-yourself skill to have no matter what career you chose.”

Many facets of science

Junior Veronica Batres found that to be true. Though she intends to pursue a career in optometry, her composting experience opened a window into the world of research. She said in real-world research, people don’t use skills from one particular science-type only, but pull from a variety of science backgrounds.

Students work on wine pomace composting project at the Wine Science Center.

“It was a great learning experience for me,” she said.

Aaron Pelly, an environmental science major, said the project gave him insight into a possible career path, while expanding his understanding of both chemistry and biology.

“It helped grow my interest in soil science,” he said. “That’s a career path I’m considering.”

Achieving the best mix

The students created eight compost recipes from pomace at the Wine Science Center, incorporating leaves, grass and cow manure to complete their mixtures.

Composting is a natural process of decomposition where diverse fungi and microbes “eat” the organic material, breaking it down into food for plants and healthy soil, Graber said.

“The wine pomace is very acidic and needs a certain composition to accomplish proper composting,” said Elsa Silva-Lopez, a chemistry adjunct professor who teaches the linked courses with biology professor Elly Sweet. “The students had to come up with a recipe that, based on their research, would do well.”

“The project provided students the opportunity to solve a real-world problem,” Sweet said.


Elly Sweet, WSU Tri-Cities biology, 509-372-7525,
Elsa Silva-Lopez, WSU Tri-Cities chemistry, 509-372-7421,
Maegan Murray, WSU Tri-Cities public relations, 509-372-7333,