Grinding whole berries to maximize fiber
I just ordered a hand-powered grain grinder that adjusts from coarse to fine, and intend to grind my own rye and wheat flours as needed for a recipe. My reason for doing this is to stop buying wheat (all purpose and whole) and whole grain rye because the whole grain wheat is too fine and the cost of KAF's pumpernickle is too high.
I understand that not all that long ago home bakers ground their own wheat and rye berries and used a coarser flour than the dust-fine commercial products of today. The coarser grinds (perhaps more meal than flour?) had more fiber which fed our microbiomes in the large intestine. So, my two questions: 1) about how fine/coarse should I grind the berries? and 2) how can I measure grind size since the control on the grinder handle is not marked in any way?
All insight on adding this capability to my baking will be much appreciated.
no matter the fineness or coarseness of the grind. You can reduce the fiber content of the flour by sieving out some of the bran but you can't increase the fiber content of the flour.
Which mill have you purchased? Someone here might have the same mill and be able to give you pointers for its use.
If you want to get a sense of the particle sizes that the mill produces at each of its settings, you'll need a set of sieves that have different mesh sizes. By sieving a sample of flour/meal of a known weight, you can then measure the weight of the flour/meal that is retained in each of the sieves, from coarsest to finest, along with the flour/meal that passes the finest sieve. Each of those will be a percentage of the original sample weight.
Even without sieves, you'll be able to determine how coarse or fine the particles are by visual inspection and by rubbing the flour/meal between your fingers. Note that I'm not saying you'll be able to measure the particle size, just that you'll be able to perceive the differences between samples.
Once you've milled flour/meal at different settings, bake with it. You'll be able to sort out in short order just what texture you like best.
Paul
Remember if you can't find a grind that suits your tastes - there are 2 ways to change the ratio of Bran : Endosperm.
Sure the first option you know exactly what is in your flour - you just have the bran to find a use for. The second option - you use everything you grind.
I doubt think grinding, especially at home, reduces particle size nearly finely enough to really alter anything about the fiber contained in a grain. But there is evidence that grinding finely can change some fiber to behave more soluble fiber instead of insoluble:
https://www.hindawi.com/journals/ijps/2016/6269302/
I only skimmed it and it is on fiber in grinding orange peels, but it probably applies to some extent to grinding wheat. Probably worth a read since you're interested. That said, the total fiber content isn't really changing—we're not grinding a polymer down to monosaccharides.
From my basic and possibly incorrect understanding, on "... had more fiber which fed our microbiomes in the large intestine" soluble fiber is the kind that may be processed by microbes in your digestive system, not insoluble. So an extremely fine grind should be better for this, but it's probably not achievable at home.
Lastly, if you are set on this, my speculation is that you'll get what you're looking for if you set to the finest setting and then dial it back a little coarser. If you can feel the individual bran particles with your fingers, they are "big" for all the processes in your stomach and intestine.