A sourdough starter is just flour and water left alone long enough for wild yeast and bacteria to set up shop. The tricky part is which yeast and bacteria — and that depends on temperature, hydration, and the flour you use.
What I did
- Day 1: 50 g whole rye + 50 g water, mixed in a jar, covered loosely.
- Days 2–4: discard half, feed 25 g flour + 25 g water twice a day.
- Day 5: switched to bread flour, same feeding schedule.
- Day 7: starter doubled predictably in 4–5 hours. Ready to bake.
The rye at the start matters. It’s full of the microbes you’re trying to recruit. Starting with white flour works but takes longer.
What went wrong
Around day 3 it smelled like nail polish — the classic “hooch” stage. I panicked and almost threw it out. The fix was just to keep feeding it; two more days and it was fine.