Ag Instructor Vic Martin: Kernels of Truth

Great Bend Tribune
Published June 17, 2018

Wheat harvest is here and the weather certainly helped speed harvest along and not in a good way.  You will hear plenty of sources willing to speak to the harvest so let’s skip that here and simply hope for a safe, speedy harvest.  The Drought Monitor as of Tuesday, June 12, showed a little improvement in spots with drought conditions at least temporarily eliminated in portions of NW and SE Kansas.  Most of our area is in the moderate to severe drought category with extreme drought in extreme SW Kansas and much of the Flint Hills region from just south of Manhattan towards Wichita.  With the projected temperatures and the wind, expect drought conditions to intensify with only a slight chance of significant precipitation early this week. 

Instead of discussing the harvest today, let’s discuss what we are harvesting, kernels of wheat.  The focus here is on hard red winter wheat (HRWW).  Hard white winter wheat (HWWW) would be the same except for the lack of tannins.  Other wheats such as spring wheats and soft wheats are similar but vary regarding items such as protein, test weight, and gluten.  Before tackling the seed, let’s discuss test weight and protein.  You will hear and see sixty pounds as the standard for HRWW.  Simply it describes the weight of a bushel of HRWW.  Sixty or greater is considered good and is one measure of quality.  Fifty-nine or fifty-eight isn’t terrible but may indicate potential problems. As you approach the mid-fifties, a variety of potential problems such as poor grain fill or wheat that has been rained on significantly which affects milling and baking quality.   What about HWWW protein.

The benchmark that millers want for HRWW is 12% or higher.  Lower protein wheat is less desirable and may result from poor or inadequate soil fertility, other stresses, or repeated rains after maturity.  Lower protein wheat may be used to “cut” protein to desired levels.  Protein (gluten – the main protein in wheat) is necessary for the stickiness/elasticity of flour and is what makes HRWW good for making baked goods like bread.  Now what makes up the seed?

There are three main parts of the seed in simple terms: the bran, the germ, and the endosperm.  The bran, which is eliminated unless using whole wheat flour, is the hard outer covering of the kernel and is high in fiber and nutrients.  The fiber here is primarily water insoluble.  In HRWW it contains tannins which help suppress head sprouting in the field.  These are similar to the tannins found in red wines and   many don’t like the “bitter” taste.  Since most of the world we can sell wheat to uses whole wheat flour, this taste is less desirable and makes HRWW harder to sell in many places.  That is why K-State has focused a great deal of energy into viable HWWW for Western Kanas.

The germ, or embryo, is what will become a wheat plant.  It is nutrient rich and where some very high quality protein is located.  Due to the presence of some fats, it is often eliminated when making flour to increase shelf life. 

The endosperm is what makes up much of the wheat kernel and is comprised primarily of starch and protein, serving as the food source for the embryo and then seedling until it can develop an adequate root and leaf system for photosynthesis to take over.  The fiber here is mostly water soluble.