Sourdough Starter

This recipe is from the Cheeseboard Collective Cookbook

Ingredients

I set up reminders on a calendar to remember to do all these things.
Day 1: In a medium nonreactive (stainless steel, glass, plastic, or ceramic) bowl, use a wooden spoon to stir 1/2 cup of warm (about 110 degrees) water and the rye flour together until smooth.
Cover the bowl loosely with plastic wrap and let stand for abobut 48 hours.
Day 3: Stir 2/3 cup of bread flour into the rye mixture until smooth; it should have the consistency of thick pancake batter. Put it in a nonreactive container with high sides (it will bubble up) and leave for another two days.
Day 5: This is called "feeding": Take 1/4 cup of starter and toss the rest. Put the reserved starter in your container and add 1/2 cup lukewarm water. Scrape down the sides and stir until smooth. Then add 2/3 cup of bread flour, and stir again until smooth and thick. Cover again with wrap and leave for another 48 hours.
Day 7 and Day 9: Repeat feeding (this is the standard feeding you'll do to use it for baking, BUT according to JR, after the starter is going, you periodically also want to refresh with some rye flour too).
Day 10: By now the starter should be rising about 1.5 times and falling back in a 24 hour period. Feed it again.
Day 11: You now have a real starter! It will keep getting better and better with use and will get more vigorous.