While trying to create a bread recipe to meet specifications of my elderly dad (trying to recreate what his mother made) a professional baker provided the following information:

"What you should try for your Dad, is mix a half batch of bread dough, put it into a container and put into the fridge. Forget about it for about five days and then remix it with half of a fresh dough and fresh yeast. That should be sour enough for him."

-- Marie (prettyhollow@yahoo.com), February 14, 2002