Hello friends.
I'm new to this and so is my starter. Question. This morning I fed my 100% hydration starter and it doubled in size in about 8 hours. Not wanting to dump it out to refeed, I just stirred it vigorously and within half the time it has tripled in size! Can anyone please explain to me what might be going on here? Is this OK to feed and then stir as a routine?
Thank you!
I just give mine a stir sometimes but instead of feeding. You dont want it working too fast and eating itself to destruction.
You will need to use it and build it up again to relieve it of its dead mass and stop bad bacteria accumulating.
Working up the activity is good if you use it every day.
Congratulations. You've stumbled on the classic demonstration of how our starters peak and quit not because they run out of food, but because they poison their environment, primarily with CO2 which stirring releases.
Some bakers do just what you've done before seeding a levain with their starter: Ian Lowe of Apiece Bakery (Launceston, Tasmania) pitched this step during is brief tenure as a Fresh Loaf contributor some years ago. He favored stirring it down multiple times (until it was "soup", if I recall) before seeding a levain with it. Presumably that contributed a flavor benefit because it certainly wouldn't help crumb structure since overgrown starters elaborate proteases that are the enemy of open crumb.
A single 'stir-down' before the final grow-up before seeding a levain probably won't hurt anything. But remember, if your starter's bugs have, say, a 1 hour generation time, then in 8 hours of growth you have 2^8 (=256) times as many bugs in there and when that grow-out peaks, they will be desperate (= seeking amino acids to make new proteins by spewing proteases to chew up any proteins in the neighborhood), and you want happy bugs, not desperate bugs to raise your doughs.
Like every 'good' idea you come across regarding bread baking -- try it and compare it to just feeding them normally that last time before seeding your levain.
Tom
Hi Tom,
This was a very helpful and thorough explanation. I appreciate your response.
Meryl
In a book I read when I was getting started, the author indicated the organisms in sourdough not especially mobile. They multiply and, I guess, exhaust the food supply in their vicinity, but they don’t roam around looking for more. So there would still be quite a bit of food supply remaining in a starter that is past its peak. You can feed them either by introducing more flour to the mix or simply by stirring the starter and getting them near to the residual still there.
The context of this point was an explanation for why dough that has reached peak fermentation will rise again after you have degassed and shaped it.
Not being a microbiologist, I can’t say how true it is. But this “fact” has stuck with me for years, and I think dough and starter generally behave as if it were true.
I’d recommend against doing this regularly, as a feeding strategy. I’d think the starter would tend to degrade.