starter unhappy, smells vinegary/vomity, after accidental overfeed
Backstory:
Ermintrude is an established, reliable 100% hydration white flour starter who has always smelled yeasty when hungry, yoghurty when happy and alcoholic (like brandy, in fact) when neglected.
She has been dormant in the fridge since Easter and I decided last week to bring her out and get her back to normal activity at cool room temp, feeding twice a day. I've revived her after dormant periods before with no problem, she starts rising well very quickly and the brandy smell settles down after a few days, returning to the usual yeast/yoghurt smell.
But I done messed up. I usually weigh feeds, but the batteries are gone in my scales, so I was feeding by volume, 2 parts flour to 1 part water. Except one morning I got it the wrong way round and added 2 parts water to 1 part flour! The only thing I could think to do was add another 3 parts flour to get the right proportions, but it amounted to a massive overfeed which more than half filled the jar and meant the starter overflowed onto the worktop later that day.
Ever since, Ermintrude has still been rising well but has an unsettling smell, which reminds me of a combination of vinegar and vomit. one website suggested the vinegar smell means the starter has suffocated and gone anaerobic; other sites associated the vomit smell with early-stage starters, making me wonder if it's unbalanced to the point that some undesirable bacteria are taking over.
Any advice? Will Ermintrude forgive me? Should I do anything special like cutting down on feedings, or just keep on as normal and give it time? I'm worried!
... but I am dying to hear what others have to say about this!
Your assessment that the bacteria and yeast populations have gotten out of balance is probably correct. And it is possible that some undesirables have taken advantage of the upset.
If you are willing to experiment, take a small amount of starter, say 25g, and add 50g of water and 50g of whole rye. That keeps the 100% hydration level you are accustomed to but gives this offshoot of Ermintrude something entirely different to consume. Let the starter peak and begin to fall before discarding and refeeding the same quantities again, all at temperatures somewhere in the 75F-85F range. The hope is that after a few cycles of feeding, enough new helpful organisms will have taken hold to out-compete the nasties that seem to have taken over. Once this daughter starter is healthy, you can begin to change the feedings to include more white flour and less rye until you are back to your all-white preference. Until you have established the healthy daughter starter, continue to feed the parent starter as an insurance policy against either one failing completely.
I usually associate a vinegar odor with an aging starter that has switched over from producing lactic acid (the yogurt odor you mention) to producing acetic acid. My starter tends to smell more like acetone, the stuff in fingernail polish remover, when it is past due for a feeding.
I hope this helps you get your starter back to what it should be.
Paul
Thanks Paul,
I annoyingly ran out of white flour and have done a few feeds with whole wheat. This was probably a rash decision based on a vague memory that sourdough likes whole wheat. I may not be handling this as well as I could...
Starter still rising well but smelling faintly of cheese.
Do you think it would be worth feeding with pineapple juice instead of water?
My thinking is that this seems rather like the 'awkward adolescence' stage of a new starter, so maybe it isn't acidic enough and the "pineapple juice solution" might help?
and will produce a stronger acidity, in my experience. That's not bad, it's just that the two kinds of flour provide two different kinds of material for the yeast and bacteria to feed on and their outputs are altered accordingly.
A bit of pineapple juice won't hurt. I doubt that it is necessary if you are already noticing a cheesy odor, since that would indicate the lactobacilli are regaining their former dominance. If you do use the pineapple juice, make sure that it does not contain any preservatives.
Sounds as the the starter is on its way back to good health. Good to hear!
Paul
Oh good! I thought that was a bad thing. I'll stick with the wholewheat for a little while and see how it goes.