I keep about 50 gms of starter. I never feed it until I want to make bread. It can sit in the fridge for weeks before I need it. When I want to make bread, I feed it so that the amount of water and flour that I add to the 50 gms is slightly more than I need for the recipe. If I need 100 gms of starter, then I feed it about 55 gms of flour and 55 gms of water. Then I’m back down about 50 gms of starter. I never discard. So wasteful. Go to foodbodsourdough.com. She even has a YouTube video. There is also a group on Facebook called sourdough for beginners. So many helpful hints are available.