The first batch of starter I ever tried looked fine, and yet the sponge sat there stubbornly refusing to grow. Undaunted, I started over and my second batch worked perfectly, and I've been successful ever since. I hope this series of posts and videos has, at the very least, inspired you to give it a try (or two), and experience the joy and taste of homemade sourdough bread. Enjoy!
Regarding your leftover sponge:
In yesterday's post I mentioned to refrigerate the leftover sponge. Now that you have a living, growing sourdough, you can use this to make unlimited batches of new sponge. Simply repeat the feeding step we did each day at the beginning of the series, but you only need to do this once a week.
When you are ready to make bread, let this come to room temp, and repeat the sponge making step. After you use the 2 cups to make the sponge, store the leftovers and so on, and so on. Some bakeries claim to have starters that are decades old. I poke a pin hole in the plastic lid I use to store it, since it produces carbon-dioxide and you don't need any explosions in the fridge. While it's being stored, any dark liquid that forms on your starter (called hooch) can be stirred in or poured off.