The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Sifting percentages

Lörren's picture
Lörren

Sifting percentages

Hi.

 

I am going to try to sift out the bran from a grain, after I have milled the grain in my Fidibus 21-grainmill, and I wonder how many percent of the wheat-kernel that consists of bran?

Is it something like 25% or something like that? Does it differ between different grains?

I am going to weigh the kernels before milling and sifting but I want to know how much weight the bran would consist of? So that I know when the bran is almost completely gone.

In other words, how do I know that I have sifted away all of the bran, by weighing the grain, after sifting?

 

proth5's picture
proth5

tell me that for wheat flour at 72% extraction you have removed the bran and most of the germ.  That would make the bran about 25-28%.

I do not have references on other grains, but I would guess that this would vary from grain to grain and maybe even varieties within the same grain. I'm sure someone else will post telling me that I am wrong about that - but it is just a guess.

Good luck with getting separation of the bran so that you get all of the bran out of the flour.  My experience is that some bran makes it through all but the very finest of seives.  If you come up with a good method, let us know.

Happy Milling!

Lörren's picture
Lörren

Okay.

So is it possible to sift out all of the bran with the sifting-attachment that comes with the Komo-grainmills? Or is this just wishful thinking?

Is it possible to get rid of all of the bran?

proth5's picture
proth5

about the Komo sifter attachment.

I do know that it is possible to sift home milled flour so that it appears that all the bran is removed.  I've done it. For me, it required a #100 mesh seive (a soil classifier, actually) and a fairly long process (including repeated remilling) to get 40% yield of pure white flour.  An interesting experiment - but really not worth the effort.  The 75% extraction rate that yields straight flour is for roller milling - not burr milling.

What is your goal in attempting this?  I ask because most people home mill to get good, fresh, whole grain flour along with its intoxicating taste. (oh, and the nutrition...)  Usually the process of getting white flour is not one for home millers - although it is interesting if you want a challenge.

 

Lörren's picture
Lörren

Okay.

My goal is to get good quality flour but not a whole-grain-flour. The reason is because of the hype around fibers that have taken place in western countries the last 20 yeasrs or so.

I don't believe that whole-grains is always better/healthier. And I know that a lot of traditional peoples around the world sifted their grains throughout history. 

Personally I don't believe that whole-grains are healthier for you. Especially if you are making an unyeasted flatbread of some kind. But what my opinion is  about whole-grains are an entirely different discussion.

You said something about a 75% extraction. How high extraction is there in whites flours that you can buy from the stores?

My goal is not to create commercial white flour, that is extremely refined, but to create a stone-grinded flour with most, or all, of the bran removed. Would that be possible?

 

proth5's picture
proth5

a whole grain purist myself - I won't go down the "nutrition/hype" path.  I just wanted to understand your goals in this.

If the flour you buy from the stores is straight flour (and it probably is) then it has about a 75% extraction rate.  Again, this flour comes from roller mills which are highly effective at getting  bran/germ separation.  You will not acheive this with stone grinding.

You might want to reasd some of my very old blogs (and those of bwraith) on sifting various flours - including a couple where I actually hand milled white flour. It takes patience, practice and some very fine mesh sieves to do it. 

It is all possible.  You need to decide how much you wish to sift and how much product you will lose as you gradually sift out bran and other materials. With burr milling a certain amount of endosperm clings to the bran and this gets sifted out.  If you remill finely enough to get "most" of the endosperm, the bran will inevitably get broken down and will pass through the sifter.  It becomes a trade off.  For flour that looked like white, I acheived an extraction rate of 40% - meaning that a good deal of the endosperm was left in my sieves. 

Depending on how serious you are about this you will want to learn about tempering wheat as this - if done properly - can help with bran separation. You want to get the best separation possible early in the milling process so that large flakes of bran are caught in the sifter before they are broken down by further milling.

A lot of folks just take the approach of doing one sift through a fairly fine mesh and leaving it at that.  "Some" bran is taken out and the flour is less than whole wheat.  They are happy with that.

Hope this helps. 

Happy Milling!

suave's picture
suave

I've always thought that straitght flour is just an abstract, and no one really makes it.

proth5's picture
proth5

I posted that I thought to myself "now I'm not sure that what I said was correct - I should fix it" - but I don't have access to my reference materials until the weekend, so I wasn't sure exactly what to fix it to. (I do know that at 75% extraction with bran and most of the germ removed, you call the stuff straight flour and the rest of it "bran and shorts", but if it is marketed that way, I don't know. )  I'll look it up when I can and get back to this.

A quick web search indicates that straight flour may not be just an abstract, but probably isn't what you buy in the supermarket in the US. (Where you will get patent flout at a somewhat lower extraction rate.)

What I do know is that you won't get anywhere near that degree of separation from a burr mill.

Sorry for any confusion

proth5's picture
proth5

Well, I've looked and looked.  I don't think that straight flour is just an abstract - but certainly it is not something that is frequently marketed in the USA. 

That being said, straight flour is definitely a product in the roller milling process.

Despite some internet accusations of lesser flour brands taking straight flour and bleaching it to make it look white (because you get a higher protein reading when you mill closer to the bran) - it is devilishly hard to get specs on consumer flours and internet rumors do not comprise facts in my mind.

Certainly there are European flour types that start to look like straight flour and "professional" flour with "higher ash contents" start to sound like the thing.  But while folks will call out a patent flour, I find no mention of "straight flour."

I'm going to admit to an error and say in my original response I should have said "patent" flour.

But extraction rates - oi! - get deeply into that and I am unable to answer even a simple question!

Lörren's picture
Lörren

Okay. Thank you for your explanation.

Yes I would like to achieve straight flour that is about 72% extraction, right?

What do you mean by tempering the wheat? Should it be warmer before milling or something? To get a good separation? And how can I learn more about this process?

If I am understanding you right, you mean that I could probably do it with a Stone-mill but that I will inevitably lose some of the endosperm along the way? 

I would like to do the trade-off and get rid of all of the bran. If I understand you correctly that means that, with a good tempering, I could probably stone-mill the grain and get rid of most of the bran?

You are talking about fine sifters. Would the sifting-attachment that comes with the Fidibus 21 be good enough for this purpose? 

 

proth5's picture
proth5

Please read my and bwraith's blogs because they will show you what might be involved in your goal.

Tempering is a process of adding controlled amounts of moisture to wheat and allowing it to rest and fully absorb this moisture to toughen the bran so that it remains in larger flakes when milling.  You can learn about it in the blogs mentioned above or in any good professional milling textbook.  You will want a moisture meter to do this as "just guessing" can result in some very real damage to your mill if you guess wrong.

I acheived about 40% extraction level when burr milling white flour.  Much of what would normally go into the flour bag when the grain is roller milled stayed behing in my seives.

You will also need to get into the topic of correcting the falling number of the flour.  This is done by introducing very small amounts of diastatic malt into the milled flour.

And you will want to consider aging your flour.

Yes, it can be done - but at a cost much greater than what you would pay for even premium white flour.  You will lose a great deal of your initial wheat volume.  If this is a challenge to see if you "can do" or you have a particular wheat that cannot be obtained commercially - I say go for it.  But if you are thinking of doing the weekly baking for the family with your own, home milled white flour - it might prove to be too much to handle.  Having done it (and successfully) - I don't recommend it to any but the most intense home millers.

I needed a #100 mesh seive (very fine mesh) to get white flour.  I have not used the Fidibus sifter, but don't think it comes that fine.  I use soil classifiers - altough others have used other sifters.

Good luck!

Blacksilk Helen's picture
Blacksilk Helen

More beneficial than if all the bran remains in the flour.  Please look at this article to clarify the matter.http://www.westonaprice.org/food-features/living-with-phytic-acid

dabrownman's picture
dabrownman

long autolyse and sourdough remove the offending acid almost completely from grains so it is not an issue. The benefits of bran remain as a result and there is no question that whole grains are much better for you nutritionally than sifting out the bran. I suppose it you didn't;  do a soak, use SD or bake the bread, removal of the bran might be a wash nutritionally.  Thankfully this isn't much of an issue for SD bakers.

Happy SD baking

Blacksilk Helen's picture
Blacksilk Helen

dabrownman, you're absolutely right about fermentation removing antinutrients.  I have always used whole grain flour that I grind in a Magic Mill.  Would like to get back to using my hand crank Diamant.  I probably will sift some to obtain the high extraction flour that I use in Hamelemann's Miche.  Would love to discuss this further with you.