Wheat's Role in the U.S. Diet Has Changed Over
the Decades
U.S. consumption of wheat products—such as breads,
pastas, and pizza—dropped sharply beginning in 2000,
reversing a three-decade trend of growth in per-capita
consumption. Wheat consumption fell from an estimated
146 pounds per person in 2000 to a low of 134 pounds in the mid-2000s,
a drop that may reflect public interest in lowering
carbohydrate consumption, before recovering somewhat. Interestingly, the rise in wheat
consumption that started some 30 years ago was also triggered
by health concerns. In the 1970s, American began shifting
from animal products to grain-based foods, including wheat
products, because of concerns about cholesterol and heart
disease.
Historical data indicate that there have been previous
periods of growth and decline in wheat consumption. From
a low starting point in the 1600s, consumption of wheat
flour rose to about 225 pounds per capita in 1880, and
then fell to about 110 pounds a century later. These shifts
reflected supply-side factors—including changes
in wheat production, milling, and transportation—in
addition to demand for more diversified diets.
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Yeast Breads Limited in Colonial America
Wheat production was difficult in New England and in
much of the South in the colonial era (1600s and 1700s),
making wheat flour too expensive for regular use. High
transportation costs also made long-distance transport
of wheat and flour from regions better suited for wheat
growing unprofitable. Therefore, colonists in these regions
turned to other crops, especially corn. The wealthy were
the principal consumers of wheat bread.
The high cost of wheat flour was not the only factor
favoring cornmeal breads. Most baking took place either
in Dutch ovens or in reflector ovens placed in the fireplace
until the invention of the cast-iron, wood-fired cook
stove in the 19th century. For homes without these stoves,
it was easier to deal with cornmeal and nonyeast bread
products prepared as baked-hearth flat breads.
Flour Cost Begins Falling in 18th Century
Milling costs dropped when Oliver Evans developed an
improved milling system in 1790. This system took the
wheat to the top of the mill by mechanical power, and
carried it down by gravity through the grinding process.
The Evans system reduced the labor needed in a mill by
more than half. It also increased the flour extraction
rate from wheat. Cyrus McCormick's invention of
the reaper in 1834 and John Deere's steel plow in
1837 reduced production costs and stimulated wheat production.
The reaper eliminated manual cutting of the crop and the
steel plow greatly accelerated the rate at which the heavy
prairie soils could be tilled.
In addition, early improvements in transportation infrastructure
helped reduce flour cost to U.S. consumers, especially
in areas where wheat was not widely grown. One early improvement
was the Erie Canal. Later, railway expansion made a substantial
difference. At mid-century, rail transport was one-tenth
the cost of hauling grain overland by road.
New Hard Wheat Flours Support Consumer Demand in Second
Half of 19th Century
Demand for bread was stimulated by the introduction of
hard wheats and new milling techniques that changed the
quality of the flour. Because hard wheats have higher
protein content (see box), they were better suited for
making bread than soft wheat.
Protein and Bread Making
The essential ingredients for leaven bread are
flour, water, and yeast. As these ingredients are
mixed together, enzymes in the yeast and flour cause
starch to break down into simple sugars. Yeast metabolizes
these simple sugars and releases carbon dioxide.
With kneading, unique proteins in wheat flour form
a sticky, stretchy substance called gluten. If the
dough has a strong gluten network, the released
carbon dioxide bubbles are held within the gluten,
thereby inflating the dough. This rising of the
dough creates the airy texture of bread. If the
protein level of the wheat flour is too low, little
gluten is formed, the carbon dioxide will escape
and the dough will not rise enough to create the
desired texture. About 11.5-percent wheat protein
is necessary for common pan bread.
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Until the 1870s, nearly all U.S. wheat production consisted
of soft wheat varieties. A hard spring wheat variety (originally
from Central Europe) with a higher protein content was
introduced in Minnesota in mid-1800s. Westward expansion
of the rail system allowed increasing quantities of hard
wheat flour to move to the East after 1865. A little later,
Mennonites from the Crimea brought with them a hard winter
wheat variety when they immigrated to Kansas, where the
main crop was corn. By 1890, Kansas was becoming an important
wheat-producing State by growing hard wheat. Milling durum
wheat produced in North Dakota began in 1904. After a
few years, U.S. macaroni manufacturers switched away from
imported durum.
When the new hard spring wheat was introduced, U.S. millers
initially milled this grain with millstones. The resulting
flour was not very desirable. When wheat was ground between
millstones, all parts of the kernel were ground down together.
When the resulting product was sifted through cloth, some
of the smaller brownish particles of bran and the more
yellowish parts from the germ (or embryo) also passed
through. The stone-ground flour was therefore creamy in
color with flecks of brown.
In 1880, millstone grinding was replaced by steel roller
mill technology from Hungary. Roller mills provided a
cleaner separation of the starch from the outer bran layers
of the kernel, and the nearly complete removal of the
germ and its oil. The result was finer, whiter flour that
was highly valued by bread consumers. In addition, removal
of the oil in the germ, which spoils quickly, and bran,
which absorbs moisture, made a flour with longer shelf
life.
New Wheat Products Change Breakfast in America
Historically, economic development has been accompanied
by the substitution of meat for grain in the diet, and
this was true in the United States starting in the 1870s.
However, breakfast-food manufacturers promoted the opposite
for breakfast. They convinced people to substitute highly
processed grains for meat as healthy and convenient.
John Harvey Kellogg began experimenting with breakfast
cereals in the 1870s, introducing a whole-wheat breakfast
cereal in 1880 as a health-food product. This breakfast
cereal was eventually named granola. Later, the Kellogg
brothers created a wheat-flake breakfast cereal, called
Granose, also as a health-food product. C.W. Post developed
Postum in 1895 and then Grape-Nuts in 1898.
Cooked grain (porridge) was a common dish among the European
immigrants in America in Colonial times. The Quaker Oats
Company produced oatmeal, the first successful ready-to-cook
cereal, in the 1870s. Later, Thomson Amidon discovered
coarsely ground wheat could also be cooked into a breakfast
cereal. Because of its color, he called it Cream of Wheat.
With new technologies, new products, and improved infrastructure—and
the resulting lower costs—flour consumption rose
during the 19th century. During the closing decades, consumption
remained at very high levels as new and improved wheat
products were introduced.
Flour Consumption Declines for the First Two-Thirds
of the 20th Century
From 1890 until 1920, the greatest increase in food consumption
occurred with sugar, and the greatest decrease was in
cornmeal. Rising prosperity led to a pronounced shift
from cornmeal to wheat flour, especially in the South,
and an equally important substitution of sugar for wheat
flour. Sugar prices had been dropping sharply since the
1850s with the development of improved refining technology.
After 1920, the substitution of wheat flour for cornmeal
slowed, but per capita wheat flour consumption continued
to drop. Part of the reason was a decrease in total per
capita food requirements as fewer people engaged in heavy
physical labor. Another factor was further substitution
of sugar for flour in the diet. Moreover, diets were becoming
more diversified to include more eggs, milk, fruits, and
vegetables. Prices of these items fell as agriculture
became more mechanized and transportation improved, making
distribution more efficient. Refrigerated railway cars,
for example, were especially important for perishable
foodstuffs. This more expensive diet was also supported
through rising consumer prosperity and increased awareness
of the health benefits of a more diversified diet.
The decline in per capita wheat consumption slowed during
the Great Depression and the world wars. After World War
II, the decline resumed as people continued to diversify
their diets. Supermarkets offered an increasing range
of foodstuffs, and rising incomes allowed consumers to
diversify their diet with more expensive food items.
A striking change in wheat flour use occurred in the
past century. At the turn of the 20th century, home baking
accounted for 90 percent of total flour consumption, with
commercial bakeries accounting for 10 percent. By 1945,
the bakery portion rose to 60 percent as home baking dropped
with the entry of women into the workforce. By 1990, less
than 10 percent of flour was consumed in the home.
Wheat-Product Consumption Starts To Rise Again in the
1970s
The decline in wheat consumption slowed during the 1960s,
partly because consumers became increasingly aware of
possible links between a diet high in animal products
and cholesterol. Wheat products were viewed by many consumers
at the time as a healthy, alternative food choice.
The rapid expansion of the fast-food industry also boosted
per capita consumption of wheat products. These businesses,
providing items such as sandwiches, hamburgers, breaded
chicken, pizza, and bagels, spread rapidly in the 1970s
and 1980s.
Fast food's popularity stemmed from many factors,
including:
- Reduced food preparation time, which became increasingly
important as more women entered the work force
- Greater number of people living alone and lacking
the incentive to cook for one
- Convenience of fast-food restaurants, particularly
for lunch
- Rising disposable incomes
- Relatively reasonable prices
These trends helped increase per capita wheat product
consumption in the United States for the last quarter
of the 20th century.
Wheat Product Consumption Levels Out as the United States
Enters the 21st Century
Between 1972 and 1997, U.S. wheat producers and millers could count on rising per capita food use of wheat flour to expand their domestic market. The decades-long growth ended in 1997 as changing consumer preferences, led by the adoption of low-carbohydrate diets, reduced per capita wheat consumption. Consumer interest in these diets spiked after 2000. Per capita flour use dropped rapidly at first and then fell more slowly until reaching a low of 134.4 pounds in 2005. After a decade of declining flour use, ERS estimates per capita wheat flour use at 136.6 pounds in 2008, still down 10.2 pounds from its high in 1997.
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