I killed my starter last winter. It dies a horrible death turnign to acetone smelling goo and refusing to wash out.
I killed it by not having a warm enough environment to produce sufficient bacteria. The environment was also not subject to any meaningful temp cntrol. Worse the location the culture often ended up was on the granite over top of my Miele dishwasher which got way too hot.
So this spring I started over.
I figured that my problems were:
1) Crappy flour: I was using store brand unbleached and I think they were not terribly careful about what flour ended up in what bags so I was never confident in it really being all unbleached.
2.) No temp control
I decided to buy a better grade of flour.
Then I undertook something new. I built a proofing box. It's wood and big enough to get two loaves in, has an old school mercury switch type honeywell thermostat inside hooked up to a little 12VDC power supply (left over from some electronics gizmo) that powers the solid state digital relay that handles the line voltage which powers a little 40 watt light bulb. So now I can establish a reliable temperature regiem according to my dictates.
This is where I keep my culture. I am playing with it now. Trying to develop a yeast strain that likes (or tolerateswell) the higher acidity of a rich bacterial colony by incubating it at 84 degrees F most of the time when I'm just maintaining it.
An aside to this is that I don't have some long drawn out feeding period before baking. I just load it up with lot of flour at night and in the morning I feed it again and an hour or two later away I go.
Then after I built the box - - - I cheated.
when my new culture arived I started two batches. One I innoculated with Floragen III, the other not.
The one I innoculated with floragen proved to be gangbusters withing mere days of innoculation. It has been the culture I used from the get go. It rises wheat and white equaly well. I keep the acidity of the culture rather high because I prefer the stronger flavor so it's a slow rising culture but it rises and it rises the whole loaf.
The culture I did not nnoculate was slow to develop picked an awful acetone odor and just proved to be weak..
I put built a thoird culture from the weak one and put the poor little culture on the countter to torture it and it responded with acetone. then I washed it once and fed it Floragen III. The acetone went away almost immediately.
Later I got some acidphylus lactobacilus in live form from a pharmacist. It's gotta be kept in the fridge unlike most others. And it is alive not dormant so it's immediately available.
I innoculated a sample culture with that and did not see the dramatic results I got from floragen.
So my take away is - - - ( the purists wil want to tar and feather me) - - - use Floragen.
It's got all the bacteria a culture needs and it jump starts a culture lightening fast then helps you establish a good healthy strong culture. .