In this posting, I describe the steps you need to grind home grown flint or dent corn and how to calculate your yield in bushels per acre.
Regular readers of this web site know that I've been experimenting with growing grain in my small suburban backyard. In September, I harvested my first batch of flint corn. After removing the kernels from the cob, I had about 8.5 pounds of dried corn seed to convert to corn meal.
Removing corn from the cob without the use of some sort of sheller is impractical, even for very small quantities of corn. Hand cranked shellers operate by pulling the cob through a set of teeth that separate the corn from the cob. These devices range in price from about $30 for a plastic model (doesn't look very durable) to over $230 for a top of the line model offered by Pleasant Hill Grain. While a good-grade metal hand cranked sheller can be purchased for $80, the price was still a bit high for me given the small quantity of corn I needed to shell (About a grocery bag full of dried and de-husked ears)
Searching for an alternative solution, I found a simple $8 hand sheller that worked quite well. To use it, just place the sheller over the top of the ear and twist the device while pushing down. The rotation of the teeth within the sheller remove the kernels from the cob. Using this device, I was able to shell all my corn in about 30 minutes.
There are many different styles of grain mills at a range of prices. For those interested in learning more about various grain mills, please see my prior posting, Grain Mills for Grinding Corn & Other Grains. Since our family already owns a Kitchen Aid stand mixer, I decided to purchase the grain mill attachment for that device. It proved very serviceable and I would recommend this to anyone who both owns a Kitchen Aid and is processing only small amounts of grain.
To operate the grinder, you remove a small cover on the front of the stand mixer and insert the grain attachment. Then tighten the attachment screw on the side of the mixer to lock the grain mill in place. You then load grain into the hopper at the top of the grain mill and turn the mixer on to full power.
An auger within the mill drives the grain against a rotating grinding stone that converts the grain into meal or flour. The coarseness of the grind is controlled by an knob on the front of the mill that adjusts the gap between the grinding stone and the auger -- the smaller the distance, the finer the grind. The Kitchen Aid grain mill let you adjust the the grind in 12 increments.
One caveat.... some reviewers of the Kitchen Aid grain attachment on Amazon.com mention that they damaged their stand mixers by trying to grind the grain from a kernel to flour in one pass. At their suggestion, I ground my grain in two stages; first doing a coarse grinding and then adjusting the grinding wheel to produce meal at my desired final level of coarseness. I found this system worked and did not seem to over-tax the machine.
Below is a photo of corn meal ground at level #1 (most course)
Below is another photo showing the second grinding at level #6. This produced meal that was on average about about the size of grains of sand.
One more thing to note... while I was very happy with the results I got using the Kitchen Aid attachment, I'd like to point out that that it does not produce meal that is anywhere near as consistent as commercially purchased corn meal. Most of the meal will be the size of sand but some will be as fine as flour. As a result, the mouth-feel of polenta (an Italian dish made from boiled corn meal) made from my home-ground meal was different than that produced by store-bought corn meal. I actually prefer the results from the Kitchen Aid, but those expecting an eating experience that is identical to store purchased corn meal may be disappointed.
My Corn Yield
I'm very pleased with the results of my first experiment growing flint corn, particularly since I grew an heirloom variety (Longfellow) that dates back to the time of the Pilgrims. Calculated on a yield per acre basis, I got 107 bushels per acre from my little suburban plot. For perspective, the average yield per acre on farms in top corn producing states like Iowa and Illinois is 157 and 164 bushels respectively according to a 2004 study by Purdue University. Importantly, these yields are for modern corn varieties, not heirloom ones like the variety I grew. Yield per acre has increased steadily over the last 80 years due to the introduction of modern varieties; in the 1930's, farms in Indiana produced just 30 bushels per acre on average according to the same Purdue study.
If you decide to grow flint or dent corn, here is the math you'll need to calculate your yield on a per acre basis.
- Bushel - this was once a volumetric measure but has since been converted to weight because of the inconsistency between crops like corn, soybeans, and wheat. A bushel of corn is now standardized at 56 pounds per bushel without cob, and 70 pounds per bushel with the cob.
- Acre - There are 43,560 square feet in an acre.
- First calculate your yield in bushels by dividing the weight in pounds of your shelled corn by 56.
- Next calculate the acreage by dividing your garden space measured in square feet by 43,560 square feet.
- Finally, divide the results of the two previous calculations. (Your yield in bushels divided by your space in acres) The result will be a bushels per acre measure that you can use to compare to commercial and/or historical yields.