MAY 3, 2010 Was That Blob in Your Kitchen Born in the Gold Rush? Bakers Obsess Over Pedigree of Yeasty 'Starters'; Some End Badly By KATY MCLAUGHLIN Marni Witkin normally feeds Happy twice a day. Once, she forgot to feed him for three straight days, and he looked distressed. "I'm not necessarily a good pet owner," says Ms. Witkin, a Los Angeles Web site editor. After a few extra feedings, Happy was back to his bubbly old self. Vintage sourdough starter -- a bubbly mix of flour, yeast and bacteria used to make crusty loaves of bread -- is all...