I'm using a sourdough starter from the recipe in Peter Reinhart's Artisan Breads Every Day and I have gone through several of the rebuilding cycles with it. It's been working fairly well for me and I have been refreshing it every week. It is stored in an airtight container in the fridge.
How long can the starter be left in the fridge without being refreshed before it's un-salvageable and would need to be thrown out?