Here's something to try!
I started thinking about making my own bread and stumbled upon this website.
http://www.io.com/~sjohn/sour.htm
My bread started tasting good with my sponge being 2 weeks old. I'm on my fourth batch with this same sponge (added a bit of four and water every 4 days or so after the initial sponge was made). Try it if you really like sour dough!