Yeast and flour.

[Beerhog]

I know this question is not related to brewing but I'm sure brewers will be able to answer it better than bakers. I came across a video on how to make sourdough and all the ingredients to make it was flour and water. I am puzzled, because if I'm not mistaken, flour is unmalted grain grounded into a powder which essentially is just starch. How does yeast survive and propagate in sourdough wothout simple sugars?

 

[Miraculix]

I think hydrolysis, especially in acidic environments, causes the starch to degrate partially to simpler sugars. At least this is how I explained this to myself when I had the same question. But I was actually thinking more about bakers yeast which is not lowering the pH as much as the bacterias in sourdough do. So still a bit of a questionmark to me.

 

[DBhomebrew]

There may be some other stuff at play, but plenty of baking flours are made of malted wheat.

When you're dealing with sourdough, the quality of the flour really does make a huge difference. Unbleached, unbromated. Stoneground preferably (lower processing temps). Even if your loaves are 100% white flour a little whole wheat, or better yet rye, will give added nutrition and health to your starter.

For me and my purposes, I don't care too much about which flour I use (high-protein, -gluten, 00, etc) as long as it's good quality. My wife brought home a big bag of grocery store bleached white flour and my sourdough definitely suffered.

 

[Miraculix]

There may be some other stuff at play, but plenty of baking flours are made of malted wheat.

When you're dealing with sourdough, the quality of the flour really does make a huge difference. Unbleached, unbromated. Stoneground preferably (lower processing temps). Even if your loaves are 100% white flour a little whole wheat, or better yet rye, will give added nutrition and health to your starter.

For me and my purposes, I don't care too much about which flour I use (high-protein, -gluten, 00, etc) as long as it's good quality. My wife brought home a big bag of grocery store bleached white flour and my sourdough definitely suffered.

It is not about the added nutrition but about the added microorganisms. These sit on the outer shelf of the wheat, which is removed more and more the whiter the flour gets.

Whole wheat has still the complete outer shelf and all the microorganisms on it to kick-start the sourdough fermentation. You want that. Once it has really started, you can swap to white flour.

 

[Vale71]

There are some simple sugars even in unmalted grain. They're residue from the plant's metabolism. Granted it's only a few percent of dry matter but that's plenty enough to feed the yeast and to produce enough CO2 to leaven the dough.

https://popups.uliege.be/1780-4507/index.php?id=8700
Just scroll down to Table 1.

 

[mashpaddled]

Flour is full of yeast and bacteria. Unfun fact: a surprisingly number of people get sick every year from consuming raw dough due to the growth of e. coli and other pathogens in the flour. Sourdough starters have been fed to grow up a population of the right yeast/bacteria and knock down the undesirable ones (like e. coli). Many yeast and bacteria produce enzymes that break down starches to sugar which is how you make sourdough without adding sugar to the dough to ferment it.

Some brewing yeast have the same diastatic qualities--this was a huge issue with alleged infections of White Labs products with diastatic yeast a few years ago.

 

[TLaffey]

Flour, water and salt.

I've been making sourdough using a starter I got from King Arthur Baking. It's been interesting because the dough gets "wetter" the longer the fermentation continues. Eventually the dough will just turn into a melty mess of starter if you wait too long before popping loaves into the oven.

 

[DBhomebrew]

Flour, water and salt.

I've been making sourdough using a starter I got from King Arthur Baking. It's been interesting because the dough gets "wetter" the longer the fermentation continues. Eventually the dough will just turn into a melty mess of starter if you wait too long before popping loaves into the oven.

Yep! Those are definitely over proofed! You're seeing the gluten structures falling apart.

 

[IslandLizard]

Grain is covered in lactic acid, when milled, then hydrated, it drops the pH and starts the sourdough process. King Arthur doesn't do anything that makes it work better or faster.

 

[Ninoid]

I know this question is not related to brewing but I'm sure brewers will be able to answer it better than bakers. I came across a video on how to make sourdough and all the ingredients to make it was flour and water. I am puzzled, because if I'm not mistaken, flour is unmalted grain grounded into a powder which essentially is just starch. How does yeast survive and propagate in sourdough wothout simple sugars?

I think that mixing and squeezing the flour releases the gluten that is the food of the yeast because it is known that bread with a lot of gluten-free flour rises less.

 

[monkeymath]

Flour contains enzymes which break down the starches, just like in the mash.

I think that mixing and squeezing the flour releases the gluten that is the food of the yeast because it is known that bread with a lot of gluten-free flour rises less.

I don't think yeast metabolizes protein. The gluten is what binds the dough together and "holds" the CO2 - which is why gluten-free dough does not rise significantly.

 

[Vale71]

I think that mixing and squeezing the flour releases the gluten that is the food of the yeast because it is known that bread with a lot of gluten-free flour rises less.

Yeast don't eat gluten, they eat carbohydrates. Gluten free flour rises less because of its reduced elasticity.

 

[Vale71]

Flour contains enzymes which break down the starches, just like in the mash.

No it doesn't. If it did then why bother with malting cereal at all?

 

[monkeymath]

No it doesn't. If it did then why bother with malting cereal at all?

Because we're talking about entirely different levels of conversion. At the end of the mash, your wort should be devoid of any long-chain starches (hence the iodine test), whereas a loaf of bread is primarily still a mass of complex carbohydrates, not candy.

 

[Vale71]

Because we're talking about entirely different levels of conversion. At the end of the mash, your wort should be devoid of any long-chain starches (hence the iodine test), whereas a loaf of bread is primarily still a mass of complex carbohydrates, not candy.

Unmalted cereal has no diastatic power and will not convert hence the need to make malt before one can make beer. Unmalted cereal has to be either processed with synthetic enzymes or mashed with an appropriate amount of malt.
Unmalted cereal does have a small amount of sugars and that's what the yeast will feed on. It's as simple as that.

 

[monkeymath]

Unmalted cereal has no diastatic power and will not convert hence the need to make malt before one can make beer. Unmalted cereal has to be either processed with synthetic enzymes or mashed with an appropriate amount of malt.
Unmalted cereal does have a small amount of sugars and that's what the yeast will feed on. It's as simple as that.

Enzymes are fundamental to baking. If you were baking, you would know that. If you aren't, then why do you tell people off like that without even performing a quick google search first? (here's an idea for a new year's resolution...)

The first enzyme to take action in bread dough is amylase. Amylase acts on starch (either amylose or amylopectin), breaking the starch chain between adjacent sugar rings. There are two kinds of amylase: α-amylase (alpha-amylase) randomly breaks the chain into smaller pieces while β-amylase (beta-amylase) breaks maltose units off the end of the chain.


Amylase is found in flour. Wheat kernels contain amylase because they need to break starch down into sugar to use for energy when the kernels germinate. The amount of amylase varies with the weather and harvesting conditions of the wheat, so mills generally test for it and add extra or blend flours to get an appropriate amount.

Amylases are mobilized when water is added to the flour. This is one reason why doughs with a higher hydration often ferment faster—the amylases (and other enzymes) can move about more effectively. To reach the starch molecules, amylases must penetrate the starch’s granules; thus, most of the action in bread dough happens at broken granules, where the starch is available for reaction. Fortunately, a percentage of starch granules are damaged during milling and accessible by the amylases.

 

[bracconiere]

No it doesn't. If it did then why bother with malting cereal at all?

as far as i know it does, and i malt because a 1 or 2 week sour dough mash wouldn't taste that great......(or maybe, )

edit: naw it'd probably taste like licking a wet dog

 

[TLaffey]

Grain is covered in lactic acid, when milled, then hydrated, it drops the pH and starts the sourdough process. King Arthur doesn't do anything that makes it work better or faster.

I mentioned King Arthur only to say that I didn't create a starter from "scratch" using whatever is already in the flour or air. No claims about superiority were intended.

Yep! Those are definitely over proofed! You're seeing the gluten structures falling apart.

It's interesting that sourdough seems (in brewing terms) to be a combined mash and ferment--the yeast are breaking down the starches (digesting) at the same time that fermentation is going on.