I would guess that I am an old newbie. I came to the site for kamado grill reviews, and veered off course. The subject of sourdough bread and starter is almost as "complexicated" as grilling, homebrewing etc................
I do by chance have a bowl of rye starter being refreshed while I am writing this comment. It is not rocket science due to the fact that it started hundreds or thousands of years ago, in times before measuring cups and ground flour in paper backs were dreamed of.
These are the methods used by a retired toolmaker/farmer with good results.
1) 1 cup distilled water in a clean mixing bowl
2) 1/2 cup rye flour ( Substitute any flour here, but rye flour has more of magic component that produces more sourness to the bread)
3) whisk these ingredients together to create a thin runny mixture (adjust the amounts of either flour or water to achieve the results)
4) cover the bowl with a loose cloth towel (flour sack) if flying critters are present in your kitchen. I leave the bowl open when possible to expose your gruel to wild yeast spores in the air.
5) Wait patiently for 2-3 days. Watch for small bubbles to form. Add another 1/4 cup of flour and re-thin with more water.
6) repeat the waiting/ feeding process on a 2-3 day cycle until the bubbles are really going well.
7) increase your starter volume to a quart +/- to allow saving back approx. 1 cup of good starter, and 2-3 cups to feed your new bread
8) put the 1 cup of held back starter into a clean bowl(I use Rubbermaid or Tupperware food grade hdpe) and add approx 1 cup of flour and enough water to feed the starter for a week or so. Put the bowl in a zipper bag to allow for gas expansion and place in the fridge for slow growth.
9) a day before you plan to use the cold starter, remove from the fridge to warm up, place back in the mixing bowl, and repeat the process from point of refreshing/feeding the starter
10) If you lose your starter, start from step 1
I have heard that during the refreshing process that the wild yeast in your area will gradually morph the starter into a new profile. The longer that you allow the refreshing and making of a batch of bread to continue the sharper the taste profile will become.
The process is so simple that even a caveperson might have done it.
What you need when you knead it,