i've been trial and error-ing so many donuts recipe, from the classic yeasted, water roux method, sourdough, added baking powder, etc but not ALL of them had that white ring like beautiful wide ones at the bakeries. some of them had that super tiny white ring line, like a thread but most of them hadn't. i (mostly) used up to 10 gr active dry yeast for 500gr flour, but sometimes i use less depending on the recipe. the dough after 1st & 2nd proofing is pretty good. it raised beautifully, never collapsed rarely underproofed. it never deflates either after the forge into the fryer. i live in a tropical country that weather never almost went below 20C or past 25C. i want to know what am i doing wrong, i want to consistently achieve that wide white ring "stage", not "sometimes it does, sometimes it doesn't" because i am planning to open a bakery myself.
so take what I am going to say with a huge grain of salt!
Isn't the ring caused by the dough not contacting the oil? So the higher you can get the donut to float in the oil, the wider the ring? So the trick would be to have super light and airy donuts that float up higher?
Remember that I know nothing but that’s what went through my mind when I read your post.