Eco-Conscious Entrepreneurs Clean Up with a Soap Business A couple turns restaurants' cooking oil into soap -- and sells it back to the establishments.

Waste not: Megan and Marshall Dostal at l.A.'s Osteria Mozza.
Photography by Jeff Clark

Marshall Dostal grew up in a thrifty New England household in which "throw on a sweater" trumped "turn up the heat." True to his roots, when he found work in the advertising industry and he and his wife, Megan, moved to Pasadena, Calif., he drove a 1984 Mercedes 300D that he ran on biodiesel.

He started making fuel from used vegetable oil he collected from restaurateurs. But all those gallons of glycerin, the byproduct of the refining process, bugged him. Such a waste.