Preparing grain corn for cooking
By ANTHONY BOUTARD
From GRIT magazine
The transformation of hard corn kernels into edible food follows three distinct pathways, two of which we’ll discuss here.
Archeologists believe the most ancient method of preparing corn for eating was by popping.
The hard, indigestible grain was made palatable and digestible by exploding the kernels over heat.
In the Peruvian Andes, the Inca made partially covered clay vessels for the purpose of popping corn.
At its center of origin in Mexico, corn is prepared by steeping it in an alkaline solution, then rinsing it and cooking the kernels until they are soft.
The softened grain is consumed whole or ground. Popping and alkaline steeping are centuries-old, distinctly American traditions.
Popcorn kernels explode best when they have exactly 13.5 percent moisture content by weight.
When the kernel moisture strays from the optimum, popping expansion is impaired.
Storing corn at 75 percent relative humidity achieves the perfect moisture content.
If this precise instruction seems overly technical and leaves you with a sinking feeling that you will never have perfect popcorn, join the crowd.
Among the yellowing bulletins I received from Calendula Books was a reprint of a 1946 article, “Conditioning popcorn to the proper moisture content for best popping,” written by S. T. Dexter.
At first I presumed this would have the same information given in every other publication on popcorn with some industrial-scale recommendations.
Dexter’s technique is simple.
Prepare a saturated salt solution by adding salt to water until no more salt will dissolve.
Place your popcorn in a dry mason jar with a paper towel or cloth wet with the salt solution; the paper or cloth should be soaked but not dripping. Seal the jar, and in a few days the kernels will be reconditioned.
If you have a sack of old, stale popcorn, it is worth trying to recondition it with this technique before consigning it to the chicken coop.
When popping the corn, use oil with a high smoking point, such as coconut oil. Use enough oil to cover the base of the pan. Add two or three kernels and put the pan on the stove.
When the kernels pop, the oil is hot enough to add about a quarter cup of kernels. Cover the pan and shake it to keep the kernels moving. A spatter screen instead of a lid will allow the moisture in the corn to escape from the pan, producing more tender popcorn. The moisture from popping toughens the flakes, so transfer the popcorn to a bowl or colander as soon as it has popped.
Tortillas and tamales are made from whole kernels of dry grain corn that have been steeped in a hot alkaline solution, left to soak in the solution as it cools, and then washed the next day.
The process is called nixtamalization, and the treated kernels are called nixtamal.
The nixtamal is ground wet to make masa, the wet flour used to make tamales and tortillas.
The masa makes a weak, paste-like dough that, with skilled hands, can be molded into tortillas.
These are cooked rapidly on a very hot clay surface called a comal.
Whole nixtamal is also cooked until the kernels are tender, at which point it is once again called maize, or corn.
Masa and the whole-treated kernels are also available in a dry form.
Nixtamal is easy to prepare in the home kitchen. Any type of corn can be made into nixtamal.
We use both Roy’s Calais flint and Amish butter with excellent results. We have also made it from dent and flour corn.
Flint corn and popcorn have a bit more chew to the kernels, and I think the flavor from the higher oil and protein content of those types of corn stands up better to the lime (calcium hydroxide).
Mexican markets have it in stock, often in a small 2-ounce package, which is all you need for a recipe. Slacked lime is also sold for pickling during the summer pickling season. It is caustic and should be handled with caution, especially around children.
In an enamel or stainless steel pan, combine about 1 1/2 pounds corn kernels with 2 heaping tablespoons of slacked lime and cover with water by about 2 inches.
Simmer gently for 30 minutes, to soften the pericarp. Do not boil; you don’t want to cook the kernel. Boiling will result in a bitter off-flavor.
You will notice that the lime imparts a familiar flavor and fragrance to the corn; many popular snack foods, such as corn chips and corn nuts, use nixtamal as the primary ingredient.
Remove from the heat and let the mixture steep overnight at room temperature.
The next day, pour off the lime solution into the compost bucket and rinse the kernels vigorously in clean water to get rid of residual lime. Rub the kernels between your fingers as you wash them and the pericarp will slough away, leaving the yellow or white endosperm.
Sometimes the pericarp is hard to remove entirely, especially in dark-pigmented flint varieties.
If you want clean nixtamal that will shed its pericarp, use a white or yellow kernel and stay away from the red and purple types.
The pericarp remnants do not affect the flavor or cooking quality of the nixtamal – removing it is purely a visual consideration.
Some cooks recommend dislodging the embryos from the kernels.
As far as I can determine, this is an aesthetic call, and certainly not necessary with regard to flavor.
In fact, you will discard a good deal of nutritional content in doing so.
It is possible that some types of corn have a bitter embryo, and if that is the case, ridding the corn of the embryo makes sense.
Taste the corn with and without the embryo and decide for yourself rather than leaving it to the dictates of custom.
Put the kernels in the pan and add enough water to cover them by about 1 inch. Put the pan on the burner and simmer for about 30 to 45 minutes until soft.
Salt the cooking broth to taste. Allow the corn kernels to cool. This recipe will produce about 3 pounds of nixtamalized kernels ready to eat.
You can dry the kernels on a screen or in a dehydrator before the final cooking step.
When you are ready to use them, cover with water and soak overnight.
The next day, cook until soft as described above.
Excerpted from GRIT, Celebrating Rural America Since 1882. To read more articles from GRIT, please visit www.Grit.com. Copyright 2015 by Ogden Publications Inc.
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