Milling and Cooking Maize Update
Whole kernel flint corn is virtually unavailable, except as popcorn. Milled popcorn is problematic, having a tough pericarp. Whole kernel flour corn is rare. In most cases, we are left with dent corn, ideally open-pollinated, otherwise hybrid.
With an adjustable mill and at least one appropriate sieve, we can isolate the hard (flinty, horny, vitreous) endosperm for porridge (polenta, mush, grits). The other fraction is the soft (opaque, mealy, floury) endosperm for some breads, breading, and pancakes (but not johnnycake). Here is a study of the two types of endosperm: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6694599/
I very rarely have a need for an intermediate granulation cornmeal, so I simply divide the flour from the flint with a #20 sieve. I set the upper bound of the grits with #10.
The fibrous chaff in corn has two sources: the thin, flakey pericarp (hull, bran) and the pedicel (tip cap or cob attachment). Either can be removed from the grits. Most of the bran and some pedicel particles can be blown away by fanning (winnowing). In water, the bran will be seen swaying just above the sunken grits. Pedicel particles float and can be removed by skimming with a small strainer. I want fiber in my diet, so I do not winnow. However, large pedicel particles are unpleasant. Therefore, I divide my dry grits with a #14 sieve, emerse the large ones first, stir briefly, and skim what floats. I got the idea from Anson Mills.
Mini Oven changed my life a few years ago when she pointed out that corn takes more salt than wheat. (I'd say 50% more.) (I'd also say that oats take less salt than wheat.) Separately from Carol Deppe in The Resiliant Gardener, I've discovered that a little sugar (1 tsp/cup of flour) makes a big difference in the flavor of a bread or cake of corn flour.
Happy milling.
The folks at Falls Mill in Belvidere, Tenn have a milling process similar to mine, on a much larger scale. They also mention removing floating chaff. http://www.grits.com/discript.htm
Single-pass milling of dent corn yields grits, whereas gradual, multi-pass milling of flint corn yields polenta. Anson Mills discusses the difference here: https://ansonmills.com/grain_notes/13
I just milled corn for the first time this past weekend. The corn is a yellow dent corn sold by CLNF. Though described as "whole corn", some of the kernels are cracked. The corn was run through my Komo Fidibus mill at a rather coarse setting, since I wanted cornmeal. What resulted was a pleasantly gritty meal with particle sizes ranging from fine flour to about 2mm. I used it in some barley/corn biscuits, where it provided a lovely crunch and flavor.
Since I haven't yet sprung for sized sieves, I don't have a way to separate the output by particle size. Those would be useful if, for instance, I wanted to make polenta or corn flour, since I could remill the oversized particles on a second pass.
Thanks again for the information.
Paul
In addition to some lab test sieves, I've managed to find large kitchen strainers in sizes 12, 16 (common), 20, and 32.
I took 28 g of whole-grain grits that passed a #10 sieve (2.0 mm opening) and rode on a #14 sieve (1.4 mm). I got 1.4 g of pericarp by one pass before a fan. (Little more can be gotten with a second pass.) I got .7 g of pedicel (upper right) by skimming with a tea strainer. The photo shows 6.5 g of the cleaned maize, all of the pedicel, and all of the flakey pericarp. (Before the photo, the cleaned maize and pericarp were allowed to dry on a paper towel.)
Again, I only do this for the large granulation fraction of grits. This will be eaten with grits down to #20. The photo shows what can be done with little effort.
Maize Chaff.jpg
I continue to fine-tune my maize milling process.
I typically use yellow dent corn, because of availablility and nutrition. Yellow and orange corn nearly always has Vitamin A and the related xanthophylls. Other colors rarely have it, and some colors don't taste very good.
I get three products, using four sieves and two passes. Two more sieves are used on polenta-cooking day.
In general, my flour passes a #50 sieve, my meal passes a #25 or 20 sieve, and my grit passes a #12. These thresholds are similar to industry practice, which varies.
For the first pass, I put my Retsel Mil-Rite on a moderately wide setting. The ground corn then goes to the #50 sieve. (Sifting goes faster progressing from a fine to coarser sieve.) The coarser, retained material then goes to a #20 sieve. (I use #20 on first pass and #25 on second pass to achieve better separation of soft and hard endosperm.) Retained material then goes to #12. Only pieces that ride #12 are remilled.
Second pass is on a moderately tight setting. Sifting similarly goes #50, 25, 12. There is usually very little riding #12 after second pass.
I end up with about 10% flour, 25% meal and 65% grits. Again, this is dent.
On polenta day, I take some grits and pass them through a #14 sieve. The coarse, retained fraction is immersed, and the floating pedicel is removed with a tea strainer. The -12+14 fraction gives the polenta a more interesting texture, while removing the coarsest pedicel makes it more edible.
Note: I want to correct my use of some terms in prior posts: In dry corn milling, bran includes pedicel, aleurone, and pericarp. Chaff is more relevant to wheat milling; in corn, it is analogous to the husk surrounding the ear.