Using different flours for sourdough fosters different bacteria–and flavors
phys.org
phys.org
I've made a sourdough starter last summer that smelled EXACTLY like pear. It led to discover that there's all these sorts of Esthers that are named after their smell.
https://en.m.wikipedia.org/wiki/Ethyl_decadienoate
My chemistry and biology is highschool level, and sourdough baking (+ kombucha brewing) has been a super interesting way of exploring and being curious about those fields.
Flours like rye or whole wheat don't have a lot of gluten relative to white flour. And there are a whole lot of online recipes recommending specifically those flours for feeding your starter. When you bake with such flours, you get a denser bread and when you create a starter with them, you'll struggle to get them to double in size for the same reason. They'll ferment and bake just fine. But there's just a whole lot less gluten to hold the starter together. Of course there's a wide variety of flours and milling techniques that determine how much gluten is actually in each flour. It's entirely possible to have whole wheat with lots of gluten. Rye has less of it but still some. It all depends.
I tend to use rye and whole wheat for flavoring. I baked a 75% spelt, 20% whole wheat and 5% rye flour bread last week. Very tasty. And I got a good over rise out of it (using a Dutch oven, which I highly recommend). My starter is the bastard offspring of whatever I had around to feed it for the past seven years. I started it off on regular white flour from the super market. What you'd call all purpose flour in the US, I guess. And since then I feed it with whatever I have around. When I don't use it, it lives in my fridge. For months on end. It ends up looking really sad. But then you feed it and it bounces right back. After observing that it was struggling to double in size with whole wheat or rye flour a few years ago, I now feed it with spelt flour. Which seems to work well. It's a German 1050 variety. Which means it's high in protein and gluten.
I'm feeding my starter by weight, so that I can take the same amount out when I bake, and the volume of growth really doesn't come into play.. I mix in whatever I have, mostly rye and spelt, sometimes wholegrain wheat, but it hardly ever doubles in volume and the bread comes out fine at the end of the process.
If you have a nice range of bubbles sizes forming in your newly mixed starter, you'll be fine.
Weighing things out indeed helps and I do that too because it makes things easier. But it's worth noting that people have been baking bread for millennia without access to any hyper precise measuring devices or flour milling and sieving techniques.
Mind you, this is with a starter based on while rye flour. So, a side note: HN is predominantly US, and for some reason everybody in the US seems to think whole rye flour is only good for making pumpernickel. None of the bread-baking books I saw listed this simple recipe: 350g whole rye flour, 250g wheat flour, around 500ml water, 10g salt, 50g starter, let grow for 8h, bake at 210C for 1h10.
No kneading, no fuss, bread for busy people, and extremely tasty at that. But you do need good quality whole rye flour.
Sharing my personal experience: I use a 100% rye starter (wholemeal or, preferably, German type 1150 [1]) and my starter grows ~2-2.5x in volume. Gluten has an impact but is less important when you proof in a small container (same reason you would bake a high hydration rye bread in a tin). What is a lot more important is that a) the hydration is right, so the starter is not too liquid (in my case a bit less than 100%), and b) you feed the starter in a ratio of 1:3 old:new, or even 1:5.
I use two starters, one fed with all-purpose flour and another one with rye flour. The difference I can see is that the rye one takes noticeably longer to "deflate". I.e. if I don't use the all-purpose flour starter right about after 4 hours, it'll start dropping back to its original size and in maybe 4-6 hours will have almost the same volume it started with. With rye starter the process takes more than a day. Also, for the same proportion of water / flour, the rye one feels noticeably thicker.
BTW, I buy rye flour from a Polish supermarket. Local chain supermarkets only have all-purpose and whole-wheat flours and occasionally the "00" (pizza) flour.
I think you mean Bread Flour specifically, as opposed to the All Purpose Flour that most people associate with white.
That is not so surprising. It is common knowledge that starters love rye, right? Now we have a scientific experiment to back it.
I believe the calcium feeds the lactic acid producing bacteria, favoring their growth.
Sourdough bread making is different in that you're feeding a kind of symbiotic relationship of lactic acid bacteria and natural (non-industrial yeast), and you try to get the balance of your sourdough starter right (too much bacteria - it gets sour. You don't actually want sourdough bread to be sour, except for maybe a slight hint of it. Too little - you don't get a nice bread). And there's also a risk that other unwanted bacteria start growing and destroys the taste you're looking for. So yes, for sourdough you'll have to take care of your sourdough starter. It's not that it's terribly tricky. And you can e.g. flatten it and dry it completely and keep it that way, and re-start it later. Nice if you're flying to elsewhere, for example (something I did). But even here I don't know anyone who adds salt to the starter, you add salt when you make bread, and that's purely for taste (in my household salt was forgotten several times.. everything works out exactly the same, you don't notice until you try tasting the bread..!)
They did an experiment with bakers from around the world making starters with the same flour, bringing them together and looking at what was in them. From the transcript:
DUNN: When we looked at the bakers’ hands, their skin bacteria on their hands was about half sourdough bacteria. And so they, like, have sourdough paws.
DUNN: We’ve looked at zillions of hands. We’ve never seen anything like this. And so the first result is that the bakers themselves have changed in response to their occupation.
TWILLEY: Normal hands like mine and Cynthia’s and Rob’s—they are something like 2 to 4 percent Lactobacillus.
DUNN: On the hands of the bakers, it is like it’s the star of the show. It’s wild. I mean, if it’s right, you should be able to put flour and water on a baker’s hand and it should start to ferment immediately and become acidic.
GRABER: Working with sourdough has entirely changed the microbial environment on the bakers’ skin. They’ve been colonized by their pets! Rob wonders if the bakers spend so much time with their hands in acidic dough that the sourdough Lactobacillus microbes end up with a competitive advantage over normal skin microbes.
Planning to try King Arthur's recipe next...