Sourdough starter confusion
I'm baking bread for about a year from Biga and Poolish, and now i want to start sourdough. For most of my experience i'm using Jeffrey Hamelman's book, and here is my confusion.
To prepare stiff levain starter using Hamelman's approach we are feeding it for 5 days, and then we end up with about 310 g of mature starter culture.
Then recipe for bread calls to prepare levain from 30 g starter and some wheat and rye flour and some water, let it ferment for 12 hours, and then you can make bread. It makes perfect sense to me, but what should i do with my 280 g of mature starter? I can keep it and feed it after taking out of refrigerator 3 days a week, but this is like 300 g of flour to waste every week!
Can I use 260 g of my mature starter for making bread, and then use 50 g of left over, feed it three times during week without throwing out half each time, end up at the end of the week with about 310 g of mature starter and repeat the process? My confusion is about why should I use a little amount of starter and feed it with flour before baking instead of using mature starter for baking, and use leftover to cultivate into new starter for next week?
Additionally, what is the difference between using mature starter, and preparing levain day before baking with little amount of starter?
And last question, my stiff starter uses whole wheat flour and white flour, but in recipe for preparing levain day before it calls for white flour, 30g of starter and a little of rye flour. What impact on finished product rye flour in levaining agent would have?
Sorry for the long post, if something is hard to understand i will try to clarify