Problems transitioning from rye/whole wheat to white flour.
Recently, I decided to start a new batch of sourdough cultures. Unfortunately, I've had problems with transitioning from their whole grain state to a white starter.
Over about 4 different starters (some using orange juice, some not, some using whole wheat, some rye) the initial activity was great and they seemed quite happy being maintained as wholegrain starters. Problems manifested as soon as I started transitioning to white flour.
The first thing I noticed was a very bad smell during fermentation - somewhere between rotting vegetable matter and hydrogen sulphide. This didn't seem to clear with successive feeds.
I tried to keep the feeding on a 'low ratio' of 1:2:2 or 1:1:1 and used a number of different white flours but all suffered the same bad aroma. I tried introducing the white flour gradually - no dice. I also tried the 'shock treatment' by using about a teaspoon of wholegrain starter to a much larger amount of white flour:- same problem. I also tried different hydrations with no luck.
While I don't believe the source of the unpleasant aroma is 'bad' bacteria (it's not at all like the leucs I've dealt with in the past) - I do think something is happening with the yeast and/or bacteria in the culture, causing them to struggle. Strange that I encountered no problems when using the same white flours with IDY.
Anyway, I kept feeding these unpleasant starters hoping the problem would eventually clear...and I suppose eventually it kind of did - but not in a good way! The smell diminished but so did the activity until I was left with a culture that would sit there on a 1:1:1 feed doing hardly anything (barely souring at all) and no discernible rise.
To give some idea of how limiting this can be on bread making: while my whole rye starter remains stable and active, I can't make anything other than a high percentage rye bread from it. Any time I add the rye starter to a predominantly white dough, I end up with a stinky mess. It's almost as if my rye starter has a white/ wheat allergy!
Wondering if anyone else has experienced this 'transitioning to white' problem?