So I got my sourdough starter going almost a month ago using SourdoLady's wonderful instructions, and things were going well until this past Monday. Suddenly the starter no longer rises after feedings and no longer has a delicious and yeasty smell. Instead it's smelling like pancake batter, and just barely gets a few bubbles. However, this morning when I woke up and checked on it, there was a thin layer of hooch on top. Does anyone know what's going on with it? Do I need to start over?