My family and friends have gone through a lot of failure loaves to reach this point. A.k.a. "anti-tank mine" loaves.
Funny thing about sourdough...although it is technically sour itself, it doesn't lend itself to sour tummies the way large amounts of other bread (homemade or commercial) does! Go figure! It has good stuff in it. Even though the only thing I put in it is flour, water, salt.