Young vs Mature Starter: Misc Questions
I am struggling with the difference between young and mature starter.
A young starter is when it is still growing, but to the point when it is usable for making bread.
A mature starter is when reached or just past its peak, just starting recede, the acid is increasing, but is still usable for making bread.
(The two other stages, in which the starter can't be used for making bread, are: prior to Young when it doesn't have enough yeast or bacteria etc, and too old a starter where acidity has increased to the point it's killed too many of the yeasts.)
Some miscellaneous questions:
1) What is the best way to tell in terms of appearance/odor/taste/float test/doming/doubling etc (for both liquid and stiff) when a starter has reached the viable young stage? What is the best way to tell when that young stage has crossed into (for both a liquid and stiff) the mature stage?
2) Hamelman calls for "mature" starter for the seed/chef that builds the levain. Since it's just the seed, why does it need to be "mature" given it will be elaborated into the levain a tout? Wouldn't young starter work just as well. Isn't it the final levain itself that matters more?
3) For a typical pain au levain or country style loaf or miche, should the final levain be young or mature?
4) How do any of the answers to the above change for rye or for other whole grain flours?
5) Does any of this change by nationality? For instance do Italian lievito vs German Vollsauer vs French traditions favor a Young or Mature final levain (in the definitions at the top)?
"Hamelman calls for "mature" starter for the seed/chef that builds the levain. Since it's just the seed, why does it need to be "mature" given it will be elaborated into the levain a tout? Wouldn't young starter work just as well. Isn't it the final levain itself that matters more? "
If you think about it, a newly mixed levain is a young starter. I don't know the answer to your question for sure, but the farther along your starter is, the more of a head start the levain will have when mixed. OTOH, you probably don't want the starter to have turned soupy before mixing the levain.
The maturity the starter should have will presumably depend on how acidic you want the result to be, vs how quickly you want the dough to ferment. I'm usually going for long bulk ferments, so I don't mind a slow start and in fact would prefer it.
TomP
A mature starter is a starter that has reached target values of leavening power (gassing power) and acidity (expressed as TTA). A young starter hasn't. It has nothing to do with the volume of the starter, or its composition, or its hydration. Ot has to do with the microbes inside that starter.
The only professional baker that uses young starter in baking that I know of is Chad Robertson, Tartine Bakery. His starter is about 100% hydration, 50% whole wheat, 50% bread flour. He uses it to mix his Tartine dough very soon after feeding it, when it barely swells, raising up maybe only 10%. The starter itself in between uses it maturing normally and is fed on time around the clock. It is only for baking Tartine bread that Chad prepares a portion of young starter. It has very low acidity and a unique milky/creamy/buttery fragrance. Chad says that he uses a very young starter because he does not want his bread to be sour even though it's a sourdough bread.
The rest of the bakers tend to use mature starters. That is what the bread formulas assume, count on.
Well, see my description of Chad's young starter above as an example.
Measure its gassing power and TTA once and remember its looks and its odor at that point.
Or follow what the author of the book is saying about their starter's readiness for baking. French stiff white flour starter, for example, is ready (mature) if it quadruples in volume after feeding it 1:3 in 6-8 hrs at 27C. If it rises slower than that, punch it down and let it rise to the max again, to see if it quadruples on time.
Hamelman's soft white wheat flour starter (about 120% hydration) matures in about 12-16 hrs at 22C after being fed 1:11. It peaks, stays at peak for several hours, and then begins to slightly recede. If punched down or stirred, it will quickly rise again, more than doubling in volume in one hour (this is its gassing power test).
Because mature means a standard number of yeast and bacteria cells per gram of flour in a starter. By measuring a certain number of grams of starter, you add with it a certain number of yeast cells to your preferment or bread dough. Then your levain or bread dough will mature on schedule which is important in production.
Levain, just like yeasted poolish or a yeasted sponge, is not a starter, it is part of the bread dough, an auxiliary step in preparing bread dough. Its purpose is not to proliferate yeast and bacteria in it but to create bread's taste and aroma and to condition its gluten if there is gluten in it.
Mature. Levain is always mature. A starter can be young, mature, ripe or overripe, but a levain can only be mature. Otherwise, it will spoil your bread and ruin your business.
Rye does not have gluten which you need to protect from deterioration as you wait for your starter to mature. Wheat starters have gluten, so unless your wheat starter is very liquid, a wheat starter has to be punched down or stirred each time it peaks, to protect its gluten from collapsing as you wait for the starter to mature (the numbers of yeast and bacteria to multiply in it).
Rye does not equal whole grain, of course. Whole grain rye flour is not used that much in rye baking. Other extractions (white/light rye flour, very white rye flour, medium rye flour, dark rye flour, rye schrot, etc.) are used more often in rye baking if taken as a whole.
A levain is always mature.