Starter life-cycle.

A maintained levain with a vigorous, healthy culture can sometimes pass a float-test after only fermenting for about 2 hours from last feed. Some inoculate their dough with a young levain to develop a sweeter, less sour loaf.

But the more common rule-of-thumb is that the levain is ready to inoculate the dough at approximately 12 hours from the last feed if it has doubled.

Where does that 12 hour mark come from? I read a series of posts by Mariana that was educating. The levain will continue to generate gas and the microbes will continue to proliferate well passed the 12 hour mark of a healthy levain but generally the gluten is not well developed (nobody kneads their levain) so the levain deflates.

So why the 12 hour mark? And shouldn't that change based on feeding ratio? A 1 : 0.5 : 0.5 will double very quickly, and a 1 : 10 : 10 will take much longer. Shouldn't that 12 hour rule always be related to the feeding ratio? And if the culture is still proliferating and active, why is the 12 hour the approximate peak time for inoculating and fermenting a dough?

Thanks.

I'd watch the levain and not the clock. My levain today was ready in 4 hours. It all depends on how big a feed and temperature.

I think the 12hr ferment is most targeted when the starter is setup for twice a day feedings. But as Abe said the levain will dictate when it is ready. You are correct. You can vary your mix and especially the temperature to time your starter to your desired stage at your chosen time.

UpDate - Tom I read the link you mentioned. I started that link when I was learing to get my starter on a 12 hr cycle. Mine was peaking at 8 hr and I didn’t want to feed it 3 times a day. The part where Mariana mentions kneaded the dough for a super long time is not something that you need to do. She was using that as a teaching principle, not daily feeding.

You mentioned a young starter making a non-sour bread and an over-developed starter a sour bread. I am getting ready to write something that a lot of people will probably disagree. I believe you can take most active starters (probably all) and make very sour tasting sourdough bread without fermenting them to a sour (over-ripe) state. I am a “sour freak” and regardless of the sourness of the starter, I get sour bread by extended fermentation of the dough. If you can develop sour by fermenting a starter for a long time, then you can get sour flavored bread by extending the frementation of the actual dough. I not aware that this belief is popular, but I experience this on a regular basis. I target the use of my starter to max rise or just begnning to recede. It is at this point where the yeast are maximized. If I let the starter go longer the Lab would begin to dominate and the yeast recede, but the flour in the levain would also be at some stage of degradation. I try my best to not bring degraded (weak and broken down) flour into the final mix.

I have been maintaining my starter without refrigeration for the last year. I ffed it twice a day at 12 hr intervals. This has caused me to learn quite a bite about how my starter behaves. Consider it a pet and train it to do want you want it to do.

Dan

Abe-That's what I was getting at. You can use a starter in as little as a couple hours if it's active.

DanAyo-I agree a sweet smelling levain can make a sour bread and vice-versa. This because the inoculation size of the levain is small relative to the total dough size and the dough can be retarded. But what I'm getting at and as Mariana was saying in that long thread, just because the starter is receding in size, that does not mean the culture is diminishing or the yeast numbers reducing. Mariana seemed to say the opposite of that. It just means the gluten has degraded--stir it and it will double gain. And the gas production had not stopped, it just was not visible, no longer being trapped due to the weakened gluten. Which means the lab and yeast populations had not diminished either. So why stop after the the levain drops in size, or ~12 hours if the quantity of microbes are still increasing?

Debra Wink worked with me to get my starter on a 12hr schedule. I mix 1:3:5 using AP flour. Because the starter is 60% hydrated, it does rise well and the drier starter prolongs the feed cycle. I do knead my starter at each feeding, but only for a mnute or two and that seems to suffice.

When my starter has been in recession for more than a ashort time, it is getting acidic. I don’t let that happen becausse my focus is on yeast. A starter cannot maximize yeast and LAB at the same time. It can max one or the other. But a starter that excels in yeast can and will have a healthy population of LAB.

But when I make bread I often convert the levain to 100%, since that is what most formulas call for.

Dan

In an attempt to answer my own question: Why would we wait passed 12 hours if the levain is sufficiently X by that point? Use it at 2 hours if it's active, doubled/passed float-test and you want to bring less amounts of Labs and yeast and a lower Lab:Yeast ratio to the dough. Use it any point after that if you want a higher Lab:Yeast ratio. Use it any point after it's sufficiently active but then significantly lower or raise the ambient temperature to foster a higher Lab:Yeast ratio as one means of attaining a more acidic loaf. And there is no need to have the levain sit for longer than about 12 hours after a feeding if it's visually active as the increasing acidity may negatively affect the leavening of the dough.