Here are a couple good questions:

Chip and Tim:

1. It took us a week to get a digital scale, so we’re just now on Day 5 with the starter. Your instructions say to use maybe 20 or 10 grams of starter per 100 grams of flour, down from 100 in the beginning and 50 recently. Really? Why so little? Or maybe we’re about to see that 10% to 20% is enough?

2. On Day 4, rather than discarding the starter that we’re not “carrying forward,” we threw it into the dough for another loaf that’s leavened with yeast. Is there any reason not to do this?

Andrew:

1) The reduction in the amount of starter you feed is based on my experience at home.  These are guidelines.  If you don’t see your starter tripling in volume or close to it within 10 days, increase the amount of starter for the feeding. This will improve the vitality of the yeast colony.  The reduction is ultimately a way for you to manipulate the fermentation and get your starter on a 24 hr feeding schedule.

2) You can certainly use the excess starter to put in other breads.  It basically becomes a flavoring ingredient.  Just keep in mind that it will eventually start to change the makeup of the dough you are making.  Also, the taste is really young at 4 days, and you will get much better flavors as the culture ages and matures.

I touched on this in previous answers, but with your starters, you are looking for a consistent ripening or “rising and falling.”  Once your starter is behaving in a predictable manner, you can begin manipulating its feeding cycle, ie faster or slower ripening, through temperature of your water and environment and/or the amount of starter you are feeding.  Once you have a level of “predictability,” you are ready to make some bread.