Dough vs Levain Flour Characteristics
Hello, first time on here but I've been an avid reader of helpful posts on here since I began baking a little over a year ago.
I have a question about sourdough's effect on the flour it feeds off in a levain.
Being that there are characteristics that make different flours behave differently (I'll use white vs whole wheat here) for example, strong white flour lends itself to easily developed gluten, whole wheat less so......what happens to those characteristics if the flour is used in a levain?
Say there is one loaf made from 500g strong white flour, and 100g of (100% hydration) whole wheat starter is used to levain the bread..
And say there is another loaf made from 450g strong white flour, 50g whole wheat, and 100g of (100% hydration) strong white levain is used instead.
In loaf #1, the whole wheat is being introduced entirely through the leavin, in loaf #2 the whole wheat is being introduced entirely during dough mixing. These two imaginary loaves have the same total whole wheat / white flour ratios. Are the nutritional benefits, structural deficiencies, etc. of whole wheat in loaf #1 lessened because of the extra fermentation?
This scenario is ignoring a plethora of other variables that would have an effect on a final loaf, but my focus is on the function of the flour here.
If that makes any sense, I would like to hear your observations/inferences/proven theories to the question simplified:
Do a flour's characteristics "dull" or change if it is fermented longer as part of the leavin?
We did this with rye flour in class. A rye bread using part of the rye in the levain as opposed to that portion of rye flour being introduced in the loaf instead. The loaf with the whole grain introduced in the mixing stage will have less volume and won't stand up as tall generally speaking. You may also notice slightly different flavors from introducing the whole grains at the levain stage. You do have to compensate you inoculation rate or the amount of time you allow your levain to ferment as the levain with whole grain will ferment more rapidly. Especially with a coarse ground whole wheat introducing it in the levain stage is smart because it allows the large particulates of bran to soften so it won't have as much of a shortening effect on the gluten.
Do you know in terms of nutrition value what exactly is different in one approach versus the other?
I mean the levain always bring the good bacteria from fermentation into play. However, wholemeal rye or wheat introduced only via the levain are also partially digested already when they get to be mixed in with the flour for the bread dough. I would speculate that there is a nutrient loss in there?
I'm not one hundred percent sure, I'm a baker not an expert in food science or a nutritionist. With that caveat aside I'd speculate that the nutritional value wouldn't be significantly effected by this switch. The main action on the grain in the levain is the fermentation and the alpha amylase action (breaking down complex starches in to simple sugars that can be fermented). Those two things are going to occur whether your white flour is in the levain or the whole wheat flour. When you say that the flour in the levain is partially digested I think the word digested is misleading, instead you should say that the flour in the levain is fermented. Generally speaking if you are creating sourdough bread with classic bread baking techniques you are going to be producing a bread that is much easier digested than the bread you would find at your grocery store...I could be wrong but that is my intuition.
“Generally speaking if you are creating sourdough bread with classic bread baking techniques you are going to be producing a bread that is much easier digested than the bread you would find at your grocery store...I could be wrong but that is my intuition.”
I would thoroughly agree with that :) It tastes a lot better, too!
So yes, you're right :)
Flour in levain is fermented. But effectively what happens as part of fermentation is bacteria eating some of the elements in the flour, then producing some other things like gas and alcohol. Which is why I said partially digested.
And this is also why I wondered about the nutrient loss. So while we gain more digestibility as part of the fermentation, I was thinking maybe there would be some loss in other aspects, but maybe it is not significant and the benefit is simply bigger.
There could be. There could also be a nutrient gain - for example if there are compounds that humans can't digest in their original form, but that we can digest if they're partly broken down.
Thanks for the replies so far!
One thing I intend to change in my bread baking habits is a more controlled levain build. As a home baker, life or poor planning gets in the way and I feed my starter with whatever I have on hand, be it King Arthur or whole meal flour I milled myself, maybe the tail end of a bag of flour at the bottom of the pile...
I never actually separate out a levain from my original starter for a particular loaf, I usually just feed my starter a certain way for a day or two in preparation and bake from that. Doing it this way makes it harder to make observations when my starters diet it so diverse.
well, the whole loaf will ferment for several hours before going into the oven. You seem to be ignoring this in your analysis. Not only will the flour used in the levain be (partially at least) digested, but all the flour in the loaf will as well.
The main difference is that the flour in the levain will have fermented much longer (the inoculation is usually higher than that of the loaf). But since we are usually talking about an inoculation of, say, 20%, I doubt that this makes that much of a difference in terms of nutrition.
The only thing I can say is that, I have baked a focaccia, using 30% levain, which contained 50% white flour and 50% rye flour. One person eating it asked me if I had used rye in the bread. So, at least you can tell the taste even in such a minute proportion (only 6.5 % of total mass of flour).