From before recorded history, through time to this Information Age,
wheat has been one of the few global constants. For each of us in this
fascinating industry, the more we study and apply the more we realize there is
to discover. This chapter does not attempt to cover the entire subject. At best
a small light will shine onto some of the many questions that might be asked by
millers. The particulars generated in it are from United States based educators
whose perceptions have undoubtedly been narrowed by their life experiences.
1. Wheat – Historical Perspective
Wheat-type plants such as emmer and einkorn are considered the
ancestors of today's wheat plant (see page 1). Researchers do not agree on the
exact time and place of the first cultivation of wheat. Most authorities do
agree, however, that wheat was an important food source in the Mediterranean region
centuries before recorded history. Wheat was not always the predominant grain
for human food consumption. Barley and rye were very important grain foods
during the Roman Empire and the Middle Ages. Over time, wheat came to be
regarded as the best of the cereal foods and dominated both international and
domestic trade. Russian Mennonites, who had grown wheat in the Crimea, brought
a hard winter wheat called Turkey Red to central Kansas in 1873. Turkey Red,
unlike any other wheat at that time, was better suited to soil and weather
conditions than the soft and semi-hard wheat early settlers had been growing.
Turkey Red spread slowly but became the ancestor of nearly all the hard winter
wheat grown in the United States.
2. Wheat – Statistical Perspective
Wheat is a significant agricultural commodity in North America and the
world, with over two-thirds of the world's wheat production being used for
food. The International Grains Council reported that U.S. yearly wheat production
from 1990 to 1999 averaged 64.5 mio t, approximately 11.0% of the world's production.
Canada averaged an additional 27.4 mio t, or 4.8% of the world total (Tab. 8). U.S.
Wheat Associates reported that Hard Red Winter represented approximately 41.5% of
the total U.S. wheat production over the same period, making it the largest
wheat class of North America. Worldwide production of wheat from 1990 to 2002
averaged 570 mio t (Tab. 9). Only China, the European Union and India with
19.3%, 16.6%, and 11.5% of the world's wheat production grew more wheat than
the United States. Based on the average price and production data for 1996 - 2000,
the average U.S. wheat crop value was 9,889.90 mio USD. In addition to wheat
crop production statistics Fig. 10 shows the world wheat situation with respect to consumption and ending stocks. World wheat stocks are the
difference between a year's production and consumption added to the previous year's
carry out. This is where the North American wheat industry may tower above the
world scene. The U.S. and Canada often provide over 40% of the wheat available
for world trade and typically hold over 20% of the world wheat stocks in
storage.
Without the massive infrastructure for storage and transport, much of North America's wheat would not be available for world consumption.
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Fig. 10: World wheat production, consumption and ending
stocks 3
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Tab. 8: Wheat production – Americas – selected countries 3
(% of world total)
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Tab. 9: Wheat production – Americas – selected countries 3
(1,000 t)
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3 Data for the tables
and charts is compiled from selected data provided by the Economic Research
Service and Foreign Agriculture Services Marketing Reports of the United States
Department of Agriculture.
3. U.S. Grain Grading Standards
Plant breeding lies at the heart of assuring continued improvements in
the production and quality of a nation's wheat. Wheat improvement work had its
formal beginning in 1897, when the U.S. Department of Agriculture set up an
active programme of wheat research and development. Today, the variety
development programme is carried out by experiment stations maintained by a
number of states as part of their agricultural college and university systems.
The experiment stations are the primary source of new wheat varieties and help
to maintain the uniformity within a wheat class. Plant scientists at these
federal and state stations are guided not only by the need of farmers for high-yielding
wheats that resist drought and disease, but also by the quality requirements of
millers and bakers at home and abroad. (Taken from U.S. Wheat Assoc. website)
Today, the United States has eight classes of wheat described by the
Federal Grain Inspection Service (FGIS) grain grading standards. They are: hard
red winter, soft red winter, hard red spring, soft white, hard white, durum, mixed and un-classed wheat. The grading standards used
in the United States are given in Tab. 15. Important grading characteristics
include the percentage of damaged kernels, the percentage of foreign material
and the percentage of shrunken and broken kernels as well as the summation of these
defects referred to as total defects. All of these factors can negatively
impact flour yield and quality and are therefore often removed in the cleaning
operation. An additional grading factor is test weight, which is reported in
pounds per Winchester bushel 4 in the U.S. and in kg per hectoliter elsewhere.
Higher test weights are often indicative of better quality wheat suggesting easier
processing and greater flour yield over lower test weight samples. Higher test
weight does not, however, always guarantee improved milling characteristics or
flour yield because test weight as a single factor does not take into account
other important factors such as kernel size, shape and hardness, variety, and
other environment-related factors that may influence the resulting flour and/or milling quality (Fig.
11).
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Fig. 11: Influence of test weight on mill yield (after
Shuey, 1960)
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4 There are two conversions for lb/bu to kg/hL.
They are as follows:
Durum wheat kg/hL = lb/bu · 1.292 + 0.630
Other wheat kg/hL = lb/bu · 1.292 + 1.419
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