Wheat – Historical Perspective, Statistical Perspective and U.S. Grain Grading Standards


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.
Fig. 10: World wheat production, consumption and ending stocks 3
Tab. 8: Wheat production – Americas – selected countries 3 (% of world total)
Tab. 9: Wheat production – Americas – selected countries 3 (1,000 t)
Note :
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).
Fig. 11: Influence of test weight on mill yield (after Shuey, 1960)
Note :
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

Comments

Popular posts from this blog

Dough and Gluten Strength Tests

Composite Flour

Wheat Milling Part 3 (Dampening and Tempering, The Second Cleaning Section)