Point of maturity.
I’m new to bread baking. I read Ken Forkish’s book Bread Evolutions and used his formula to create my own sourdough starter or levain as he calls it.
I had no problems getting the starter going and have fed it after one week so it is currently two weeks old. But I have a question on leaving it out for the 23 to 24 hour period after feeding it. In his book Forkish talks about temperature variance during this time period and that if the temps are warmer the starter will reach “the point of maturity sooner.” I can’t find a definition of “point of maturity” in order to visually asses if the starter is ready for the fridge. In his book he states “Eventually, you’ll figure it out.” Pg 67 on my kindle.
Any guidance on what “the point of maturity” looks like?
PS- I’ve been very happy with his book and have baked most of the breads in it to great success. I just want to tighten up what I’m looking for.
Ken shows how it looks when mature on p.60. Use that picture to visually access your own levain.
He also provides a description of a culture that is fully ready. Most importantly, he gives us a time frame
Feed it 50g levain + 200g water +200g bread flour, let it sit for
12 hrs at 27-29C/80F
24 hrs at 18-21C/65F
Then refrigerate at 3C/37F for 7-10 days. Please, extrapolate the temperatures and times for your own room temperature, if it is higher or lower or in-between those in his recipe. The levain can be prepared at 10-12 C just as well as at 30-32C, it simply will take more (up to 3 days at 10C) or less (6-8 hrs at 32C) time.
When he says 'you'll figure it out', he means the acidity, whether you like it to contribute more acidity and leavening power or less to your bread. On page 67 Ken tells a story of a young levain which sat for 12-14 hours at 18-21C and was bubbly and looked good, it passed the float test and then was refrigerated, but when used, the breads took too long to rise and didn't end up with the volume they should have. The float test usually works for levains that matured for 8-18 hours. less mature or more mature levains will sink.
Below is shown the visual guide for the stages of maturity of levains with equal amounts of water and flour in them (from Modernist Bread, vol,3). Pay no attention to the timing in that table, because the proportion of feeding is different, not as generous as in Ken Forkish schedule. A mature levain should be very bubbly and there should be no signs of receding (decreasing in volume). Young levain will have a pH between 4.2 and 4.3. At its most ripe, the pH will be about 3.8-3.9 and will produce the sourest of sourdough breads.
Additional descriptions to the above table. If you start at less than 4Qt, then
young levain will rise to slightly above 4QT, 8-10 hrs at 21C/70F after feeding it,
mature levain will triple, rise to the level of 12QT, 12-14 hrs at 21C/70F after feeding, and
ripe levain will rise to the max volume of 16 Qt (quadruple), 16-18 hours after feeding it.
overripe levain will begin to deflate and potentially collapse all the way down to 4Qt volume again.
Wow, thank you very much for taking the time to put that together for me! That’s very helpful.
Two questions to help me with boots on the ground action:
1. I have PH papers, is this something people use to test for maturity?
2. The three volume increase you mentioned. I’m guessing I could mark the container and visually see when it triples in size? I’ve been sitting and looking at vids online and that seems a thing. Is that valid?
My starter was bubbly after 12 hours at 68°F which led me to think of his young starter example. That’s why I’m confused as how you tell maturity, as the bubble test doesn’t seem valid to my neophyte eyes.
Yes, pH paper can be used, but it has to be one with a finer gradation, for example, this one, for the sourdough range of acidity (Micro Essential Lab 3110M18EA 325 Hydrion Short Range pH Test Paper Dispenser, 3.0-5.5 pH).
A starter will reach the target pH value and then mature at that value for a while, accumulating more and more weak organic acids, aka flavors (pH measures only strong acids, not total acidity). Then its pH will drop a bit and again, stay at that new lower value for a while, etc.
Volume is a bit subjective in a sense that it depends on 1) your flour strength and dryness 2) how well you knead your levain when you refresh it.
The stronger your flour is and the drier, the better you knead your starter, the higher it will rise, easily quadrupling in volume as it matures and then it will stand tall for hours as it ripens without collapsing. Weaker, moister flours and barely mixed levains might only double in volume and then collapse.
So it is up to you to discover how your flour behaves in a starter, what maximum volume means for it and for how long it can stay at that max volume without deflating.
A better test for the levain readiness is "time to double". That means that a fully mature/ripe levain will double in volume at 68-70F in one hour or sooner. To check your starter for maturity, stir it to fully deflate it, and watch it rise for one hour. If it doubles or more than doubles in that time, then it is ready to be used in breadmaking or refrigerated.
This is how a mature levain looks in my case when kept for 15 hours at 22C/72F after feeding it. Note, that 72F is way higher than your 68F. For starters that difference is significant, it translates into nearly 50% difference in speed of maturation. At 68F it would take full 20-24hrs to get to that point.
It rose to the max (quadrupled) and just began to recede. You can see it leaving traces where it was at its max and now it is 1cm below that level.
To test its readiness, I stirred it down to its initial volume of 1/2 cup and let it stand for one hour.
It has more than doubled in one hour at 21C/70F, it passed the test. It is mature.
Should it not pass that test, simply let it rise to the max, stir it again and see how far it rises in one hour again. Eventually, it will accumulate enough yeast in it, to rise fast.
That’s fantastic, thank you so much! That’s really helpful stuff and I can work with that info! Thank you very very much!
Enjoy your levain! It will make you a lot of great bread. 😊
I went and looked up Modernist bread as I thought that might be a good read.
$625.00… on their website. They’re very proud of that set. Bet it’s pretty good though.
I got it for about $300 when it first came out. It is very comprehensive and innovative but not user friendly. The volumes are huge, heavy, with giant pages, with lots of different kinds of info on each page. I rarely consult it, mostly for some interesting factoids about bread and good, one of a kind, illustrations. It has a lot of info one will not find anywhere else.
I am sure your city library will have it, or you can order it using interlibrary loan service, they will bring it to your local library branch.
That’s a great idea, I have a book to return so I’ll ask then.