I am new to the board, and have a question about  recipes for sourdough starters.  I  have been looking at different recipes for sourdough and the starter in preparation for attempting my first sourdough bread.  A recipe I found in a William Sonoma cookbook called for milk and flour in the starter.  All of the other recipes I have found call for flour and water.  Has anybody made a starter with flour and milk?  Or is flour and water the standard?  Thanks for your help