Using different flours for sourdough fosters different bacteria–and flavors(phys.org)
phys.org
Using different flours for sourdough fosters different bacteria–and flavors
https://phys.org/news/2023-10-flours-sourdough-fosters-bacteriaand-flavors.html
28 comments
Exactly that smell is the smell of high-end motorcycle engine oil. Motul 300V smells amazing. “Double ester” is one of the selling points.
Using the right flour is something to use to your advantage if you are doing sourdoughs. One obvious thing from this article - not all flours actually contain gluten - has an implication for how you evaluate your starters. If you are looking for your starter to double in size, which is something world + dog insists on in online recipes, you need a flour that contains gluten.
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.
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 don't struggle to get rye starter to double in size. I don't know why. Maybe something else is at play here, not gluten. But, really, it works well (at least for the doubling in size part).
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 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.
> 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.
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.
[1] https://www.hefe-und-mehr.de/en/2014/03/mehl/
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.
[1] https://www.hefe-und-mehr.de/en/2014/03/mehl/
What's the obsession with having your starter double in size? I haven't heard about it before.
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.
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.
Rye starter might not double in size, and that's fine. In fact, mine usually go through a period of hyper-growth 2-3 days after they are initiated, but that is not when they are ready: if I make bread then, it comes out overly sour/acidic. I learned to wait another 4-5 days until the starter stabilizes and stops growing like crazy, which gives me a better balance of bacteria and fungi.
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.
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.
It's a measure of how alive/acive your starter is. If you know what you are doing, you can indeed just wing it and judge things by feel, touch, and smell, etc. But you do need to know what you are doing to be able to do that.
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.
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.
I would add that it's a measure in particular how active the yeast is in your starter culture, and yeast is the crucial ingredient for fermentation.
My brown rice flour starter doubles in size. I think gluten ones triple? Doubling isn’t so hot
> Flours like rye or whole wheat don't have a lot of gluten relative to white flour
I think you mean Bread Flour specifically, as opposed to the All Purpose Flour that most people associate with white.
I think you mean Bread Flour specifically, as opposed to the All Purpose Flour that most people associate with white.
> One surprise was that rye flour fostered a much wider diversity of bacteria than any other type of flour...
That is not so surprising. It is common knowledge that starters love rye, right? Now we have a scientific experiment to back it.
That is not so surprising. It is common knowledge that starters love rye, right? Now we have a scientific experiment to back it.
shrooms love rye, too!
The highest decorated Vodka is made from rye. Vodka judges love rye too!
Neither this study nor the previous one from the same authors seems to look at the water. I would have thought the hardness of the water also influences what grows in the starter. Especially with white flour, which has few minerals.
I'd never thought about the water.. my wife started making sourdough bread a year ago, and now she's making them all the time.. extremely tasty. Her starter always seems to grow to nearly triple size. She uses mostly rye for that, I think, but she varies stuff.
The water around here has basically zero hardness. There's never any need to remove calcium from anything, ever. Never seen any calcium deposits, unlike when I lived in Italy.
Have you done any experiments on this? Using hard water vs demineralised? I have no idea if this is a thing that's spoken about in the Sourdough baking world.
I find that my sourdough starter’s smell is noticeably more yogurty (lactic acid) and less tangy (acetic) when I add a tiny amount of food grade calcium to the water. There’s a similar effect on the final bread as well, but there are other factors (eg fermentation time/temperature) that probably have a bigger effect on the final loaf.
I believe the calcium feeds the lactic acid producing bacteria, favoring their growth.
I believe the calcium feeds the lactic acid producing bacteria, favoring their growth.
If you live in Georgia, Bread Beckers is an excellent source of different grains and instruction. Most of her classes/workshops are free on YouTube as well. Changing our diet with good grains has really helped overcome some chronic health conditions.
What do you mean with good grains?
Organic or bulk/modern farmed, having a variety like white, red, soft, hard wheat varieties, kamut, oats, rye, different types of rice, beans, etc. For us grinding them directly then baking so that they have not been bleached and had nutrients added back (basically for shelf life). The "bread becker thing", without getting into religion, boils down to a philosophy that commercial flour (without even thinking about adding additional gluten) has many micro nutrients removed during the process of stabilizing for shelf life that it loses a significant portion of its nutritional value. By storing whole grains (shelf stable) and grinding it right before cooking/preparation preserves the most nutrients possible. They have hard to find (in the US) mixers, grain grinders, etc. Most regions in Georgia will have a co-op that will take monthly orders and bring them back from Woodstock so that you don't have to drive there. We live about 2 hours away and found out about it through friends and our local farmers market. They have a full kitchen there where they do cooking demonstrations and record for youtube.
Someone once told me that bread making is like managing a bacteria zoo. You use sugar and flour to feed them and use salt to control their growth.
Well.. common style bread making uses yeast, and no bacteria are involved, for the most part. And yeast also likes sugar and flour. The salt doesn't make any difference at all in my experience, as far as growth is concerned, it's purely to get the exact right taste you want. To actually impact growth I believe it would make the bread too salty to eat.
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..!)
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..!)
A great read about the importance of flour: https://www.newyorker.com/magazine/2020/04/13/baking-bread-i...
Another good read/listen is this gastropod episode (https://gastropod.com/secrets-of-sourdough/) which features cool projects like a global sourdough sequencing project (http://robdunnlab.com/projects/sourdough/), a sourdough library (https://www.puratos.com/campaigns/the-lab---18th-of-october), and it's caretaker (https://www.instagram.com/sourdough_librarian/)/
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.
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.
As a celiac i am not surprised ;)
Celiac of like 25 years here. I started making gluten free sourdoughs a couple months ago. I base my technique on the bakerita.com recipe, but now use all sorts of flours. It is amazing
I'd love to get your bread recipe! I tried my first GF sourdough recently (from a very basic 4-ingredient recipe), and it was... not fantastic. Didn't rise much at all, even after giving it a lot of time to do so.
Planning to try King Arthur's recipe next...
Planning to try King Arthur's recipe next...
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.