Glad to see a recipe for a real sourdough starter on here. I did the same thing and it worked great, but I used organic whole wheat flour for the first few days, and switched over to unbleached flour after that, exact same process though. If you want to store your starter you can feed it and immediately put it in the fridge, then just feed it again once a week.

Good recipe but imho a bit overcomplicated. You do not need to be so careful about the whole process - on day 1 just put some rye flour (just grab it from the bag using 1 hand) into glass container add enough warm water (if you boiled patatoes in unsalted water - use the water when it cools down) to make consistence of thick soup. Cover with a cloth and put somewhere near cooking range. On day 2, 3, 4, 5 ... n, once a day, preferably same time, just add some flower (again, just grab some from the bag) and stir-in warm water (no patatoe water this time) just enough to keep the thick soup consistence. After 5 to 7 days it's ready to use.