Sour Dough Starter - proofing in less than 24 hours? I recently started with making sour dough. I created a new starter yesterday. After feeding it one time in less than 24 hours it's already doubling it's size. I'm not using self-rising flour just normal wheat bread flour. 

Is it usual that it picked up so fast?
24 hours is above average but not unheard of, 24 hours is a realistic time. I'd say you have a healthy starter on your hands.