They’re back to calling it Kentucky Fried Chicken, and frying is certainly key to the tasty delight with those magical herbs and spices. And now that leftover waste oil from the thousands of fryers in the thousands of KFC’s around the world… about 500 gallons each month per restaurant… could be turned into biodiesel.

This story from the Louisville, Kentucky Courier-Journal says Louisville’s Yum! Brands… the world’s largest restaurant company which also owns Taco Bell, Pizza Hut, Long John Silver’s and A&W… is putting out a report detailing the company’s green eforts, including the biodiesel ventures:

The vegetable oil idea is still being explored for KFC’s 5,300 restaurants in the United States, and company spokesman Jonathan Blum said yesterday that the campaign likely would be tested first — possibly in Kentucky — before being expanded market by market. In some regions of the country, he said it might not make sense to convert waste oil, especially if a partner couldn’t be found nearby.

KFC produces the most waste oil of Yum’s chains, but Blum said Taco Bell also could be a candidate for the program.

The story goes on to say that Yum is building its first “green” restaurant… a KFC-Taco Bell… in Northampton, Mass., that uses solar energy , recycled building materials and evens harvests rainwater to use for irrigation.