The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

How does Oil affect crumb?

malfoypotter's picture
malfoypotter

How does Oil affect crumb?

I've researched this question and all I could find was lots of contradictory information. Some sources say that the oil acts as lubricant, allowing gluten bonds to form more easily, and some say that oil only inhibits the process.Appvalley

What I have noticed myself, is that oil softens bread. That much is clear. But beyond that, https://vlc.onl/ how does it really affect the bread? Or does it not? Is there any explanation for why sources can't seem to agree on this? Tweakbox

Abe's picture
Abe (not verified)

I think it coats the gluten strands having the opposite effect. Happen to like a little oil in the bread, 2-3% of total flour, as it makes the crumb softer and the bread lasts longer.

Of course there are lots of things that will have to be taken into account but all things being equal the more oil you put in the softer the crumb becomes with a less open and more cake-like crumb.

Can you give some sources to the contrary?

BaniJP's picture
BaniJP

Any kind of fat in a dough primarily acts as a tenderizer, which results, as Abe said, in a softer crumb. The exact science behind this I don't know, but you have to make sure you add the fat quite in the end so the gluten strands have a chance to form before they get coated.
It also increases dough elasticity and extensibility (which is the reason pizza chefs can spin those doughs over their heads) and results in a smoother dough that is easier and more precise to handle. That is probably also why it was named (falsely) "lubricant".

Obviously different fats have slightly different effects on dough, but the main role is tenderizing. For example milk fats also contain lactose, which is a nice food for yeasts. And oily doughs are often leaner than doughs with milk fats or eggs.

Robyn's picture
Robyn

Just asked the family physicist, and was told that fats and oils cannot change or modify gluten. 

pmccool's picture
pmccool

Does oil reduce gluten content?  No.

Does oil change gluten physically?  No.

Does oil interfere with the bonding of glutenin and gliadin, thereby causing shortened, weakened gluten strands in dough?  Yes.

Paul

Hermit's picture
Hermit

Shorter-chain oils (like those in canola) are liquid at room temperature and affect crumb in different ways than longer-chain oils (like coconut oil, which is solid at room temperature.)

My experience is that longer-chain oils increase the plasticity of the dough while shorter-chain oils don't as much.

To put it more concretely: if you tear apart a dough made from coconut oil or shortening, the tear happens gradually with the gluten matrix widely deforming around the tear. This is like a dinner roll texture. If you substituted canola or olive oil, you'll see the dough stretch for a while before reaching a breaking point, at which point each side of the tear will snap and snap back to form a narrow line with either side returning to its original form. This is more like (to me) a Focaccia texture.

Maybe my examples aren't perfect as Focaccia and dinner rolls themselves are made in a variety of ways. Focaccia often has no oil in it. But it gives you some idea.

 

naman johnson101's picture
naman johnson101

hello,

 

I've researched this question and all I could find was lots of contradictory information. Some sources say that the oil acts as lubricant, allowing gluten bonds to form more easily, and some say that oil only inhibits the process.

What I have noticed myself, is that oil softens bread. That much is clear. But beyond that, how does it really affect the bread? Or does it not? Is there any explanation for why sources can't seem to agree on this?

BaniJP's picture
BaniJP

I don't know if the sources you found were scientific articles or bloggers/cooks/recipes. I suppose all mean the same thing, but describe it differently, or have different conclusions. Fat coats and isolates the flour particles and gluten strands like a skin, thus making further hydration and gluten development very difficult. It doesn't stop it really, more delays it.

Excerpt from my baking book (Advanced Bread and Pastry): Hard fats like butter or shortening should be added in the end of the mixing, liquid fats like oil in the beginning, as they are part of the dough hydration.
Small quantities of hard fats (2-4%) can also be added in the beginning, larger percentages (15%+) in the end on slow speed.