Oven-puffed rice and corn are made by cooking rice grains or corn grits with water and flavorings, partly drying and lightly rolling them, then toasting in an oven that may reach 650F/340C, when the remaining moisture evaporates quickly enough to expand the grain structure.

Puffed rice and wheat are made from whole grains, which are wetted and enclosed in a pressure-cooker "gun" at a temperature of 500800F/260 430C. The steam pressure reaches 14 atmospheres, and is suddenly released, expelling the grains. As the steam within the grains expands from the pressure drop, it expands the grain structure, which then sets as it cools down into a light, porous ma.s.s.

Baked cereals follow in the mold of the 19th century original, C. W. Post's Grape Nuts: dough of some sort is formed, baked, sometimes granulated and rebaked.

Extruded cereals, usually small crunchy shapes, are made from doughs that are forced at high pressure through small openings, much as dried pastas are made. The pressure and friction generate high temperatures that cook the dough as it's shaped, and the pressure drop as the formed dough exits the extruder can cause it to expand as well.

Grains are still the base for these cereals, but they may actually be outweighed by sugar and other sweeteners. Sucrose is especially favored for its ability to give a frosty or gla.s.sy surface to the crisp grain flakes and slow the penetration of milk and resulting sogginess.

Wheat Wheat was one of the first food plants to be cultivated by humans, and was the most important cereal in the ancient Mediterranean civilizations. After a long hiatus from the Middle Ages to the 19th century, when hardier but less versatile cereals and potatoes were the princ.i.p.al staple foods, it regained its preeminence in much of Europe. Wheat was brought to America early in the 17th century and had reached the Great Plains by 1855. Compared to other temperate-zone cereals, wheat is a demanding crop. It's susceptible to disease in warm, humid regions and does best in a cool climate, but it can't be grown as far north as rye and oats.

Food Words: Cereal, Wheat, Barley, Rye, Oat Cereal, Wheat, Barley, Rye, OatOur word "cereal" comes from the Roman G.o.ddess of the fields, Ceres, whose name came in turn from an Indo-European root, ker, ker, that meant "to grow"; the same root also led to "create," "increase," and "crescent." that meant "to grow"; the same root also led to "create," "increase," and "crescent." Bhares Bhares was the word for "barley" and also gave us "barn"; was the word for "barley" and also gave us "barn"; wrughyo wrughyo meant "rye." "Wheat" came from the same root that gives us "white" ( meant "rye." "Wheat" came from the same root that gives us "white" (kweit), apparently because its flour was light in color; and "oat" came from oid, oid, "to swell." "to swell."

Ancient and Modern Wheats A handful of different wheats have been grown from prehistoric times to the present. Their evolution is fascinating and still somewhat mysterious, and is summarized in the box on p. 466. The simplest wheat and one of the first to be cultivated was A handful of different wheats have been grown from prehistoric times to the present. Their evolution is fascinating and still somewhat mysterious, and is summarized in the box on p. 466. The simplest wheat and one of the first to be cultivated was einkorn, einkorn, which had the standard genetic endowment of most plants and animals: namely two sets of chromosomes (a "diploid" species). Somewhat less than a million years ago, a chance mating of a wild wheat with a wild goatgra.s.s produced a wheat species with four sets of chromosomes, and this "tetraploid" species gave us the two most important wheats of the ancient Mediterranean world, which had the standard genetic endowment of most plants and animals: namely two sets of chromosomes (a "diploid" species). Somewhat less than a million years ago, a chance mating of a wild wheat with a wild goatgra.s.s produced a wheat species with four sets of chromosomes, and this "tetraploid" species gave us the two most important wheats of the ancient Mediterranean world, emmer emmer and and durum. durum. Then, just 8,000 years ago, another unusual mating between a tetraploid wheat species and a goatgra.s.s gave an offspring with six sets of chromosomes: and this offspring gave us our modern Then, just 8,000 years ago, another unusual mating between a tetraploid wheat species and a goatgra.s.s gave an offspring with six sets of chromosomes: and this offspring gave us our modern bread wheats. bread wheats. The extra chromosomes are thought to contribute to the agricultural and culinary diversity found in modern wheats, most importantly the elasticity of the gluten proteins. Today 90% of the wheat grown in the world is hexaploid bread wheat. Most of the remaining 10% is durum wheat, whose main purpose is making pasta (p. 571). The other wheats are still cultivated on a small scale. The extra chromosomes are thought to contribute to the agricultural and culinary diversity found in modern wheats, most importantly the elasticity of the gluten proteins. Today 90% of the wheat grown in the world is hexaploid bread wheat. Most of the remaining 10% is durum wheat, whose main purpose is making pasta (p. 571). The other wheats are still cultivated on a small scale.

Durum Wheat Durum wheat, Durum wheat, T. turgidum durum, T. turgidum durum, is the most important of the tetraploid wheats. It arose in the Near East and spread to the Mediterranean before Roman times, when it was one of two major wheats. Emmer was better suited to humid climates and had a starchy grain, while durum was better suited to semiarid conditions and had a gla.s.sy grain. Both were used to make breads leavened and unleavened, bulgur, couscous, injera, and other preparations. Southern and central Italy is now the main producer in Europe; India, Turkey, Morocco, Algeria, and the United States and Canada are large producers elsewhere. is the most important of the tetraploid wheats. It arose in the Near East and spread to the Mediterranean before Roman times, when it was one of two major wheats. Emmer was better suited to humid climates and had a starchy grain, while durum was better suited to semiarid conditions and had a gla.s.sy grain. Both were used to make breads leavened and unleavened, bulgur, couscous, injera, and other preparations. Southern and central Italy is now the main producer in Europe; India, Turkey, Morocco, Algeria, and the United States and Canada are large producers elsewhere.

World Grain ProductionThe leading figure for maize is misleading because a large fraction of the maize harvest is used to feed animals and produce industrial chemicals. Some wheat is also used for animal feed, while nearly all rice is eaten directly by humans.

Grain

Whole Grain Production, 2002 Whole Grain Production, 2002 Millions of Metric Tons Millions of Metric Tons

Maize

602 602.

Rice

579 579.

Wheat

568 568.

Barley

132 132.

Sorghum

55 55.

Oats

28 28.

Millets

26 26.

Rye

21 21.

Buckwheat

2 2.

Source: Food and Agriculture Organization, United Nations Source: Food and Agriculture Organization, United Nations Einkorn Wheat Einkorn wheat, Einkorn wheat, T. monococc.u.m, T. monococc.u.m, was rediscovered in the early 1970s in the Vaucluse region of France and the southern Alps, where it was being grown to make a local porridge. It was probably the first wheat to be cultivated, around 10,000 years ago. It grows best in cool conditions, tends to be rich in yellow carotenoid pigments and is high in protein. However, where the proportions of elastic glutenin and flowing gliadin (p. 521) are 1 to 1 in bread wheat, in einkorn they're 1 to 2. The result is a sticky, fluid gluten that's unsuited to breadmaking. was rediscovered in the early 1970s in the Vaucluse region of France and the southern Alps, where it was being grown to make a local porridge. It was probably the first wheat to be cultivated, around 10,000 years ago. It grows best in cool conditions, tends to be rich in yellow carotenoid pigments and is high in protein. However, where the proportions of elastic glutenin and flowing gliadin (p. 521) are 1 to 1 in bread wheat, in einkorn they're 1 to 2. The result is a sticky, fluid gluten that's unsuited to breadmaking.

Emmer Wheat or Farro Farro Emmer wheat, Emmer wheat, T. turgidum dicocc.u.m, T. turgidum dicocc.u.m, was probably the second wheat to be cultivated. It grew in warmer climates than einkorn, and became the most important cultivated form from the Near East through northern Africa and Europe until early Roman times, when it was superseded by durum and bread wheats. But pockets of emmer cultivation survived in parts of Europe, and emmer is now widely available under its Italian name, was probably the second wheat to be cultivated. It grew in warmer climates than einkorn, and became the most important cultivated form from the Near East through northern Africa and Europe until early Roman times, when it was superseded by durum and bread wheats. But pockets of emmer cultivation survived in parts of Europe, and emmer is now widely available under its Italian name, farro. farro. In Tuscany whole farro grains go with beans into a winter soup; the pre-soaked grains are also made into a risotto-like dish called farrotto. In Tuscany whole farro grains go with beans into a winter soup; the pre-soaked grains are also made into a risotto-like dish called farrotto.

The Wheat FamilyRelationships in the wheat family are complicated and still the subject of scholarly argument. Here is one plausible version of the family tree. Those wheats whose grains are enclosed in adhering papery husks are noted as "hulled"; all the rest are hullless and are therefore much easier to prepare for cooking or milling. Wheats in common use today are highlighted in bold type.

Wild einkorn (diploid; hulled; Tritic.u.m monococc.u.m boetic.u.m Tritic.u.m monococc.u.m boetic.u.m)

Cultivated einkorn Cultivated einkorn (diploid; hulled; T. monococc.u.m monococc.u.m T. monococc.u.m monococc.u.m)

A wild wheat, A wild wheat, Tritic.u.m urartu Tritic.u.m urartu + a goatgra.s.s, + a goatgra.s.s, Aegilops speltoides Aegilops speltoides Tritic.u.m turgidum (tetraploid): (tetraploid):Emmer (hulled; T. turgidum dicocc.u.m T. turgidum dicocc.u.m)Durum ( (T. turgidum durum)Khorasan (T. turgidum turanic.u.m)Polish (T. turgidum polonic.u.m)Persian (T. turgidum carthlic.u.m)Tritic.u.m turgidum + a goatgra.s.s, + a goatgra.s.s, Aegilops tauschii Aegilops tauschii Tritic.u.m aestivum(hexaploid):Common, bread wheat ( (T. aestivum aestivum)Spelt (hulled; T. aestivum spelta T. aestivum spelta)Club (T. aestivum compactum) Kamut Kamut is the registered trademark for an ancient relative of durum wheat, a subspecies of Kamut is the registered trademark for an ancient relative of durum wheat, a subspecies of T. turgidum. T. turgidum. The modern production and commercialization of kamut (Egyptian for "wheat") began after World War II, when seeds said to have been collected in Egypt were planted in Montana. It's characterized by a large grain size and a high protein content, though its gluten is better suited to pasta than to raised breads. The modern production and commercialization of kamut (Egyptian for "wheat") began after World War II, when seeds said to have been collected in Egypt were planted in Montana. It's characterized by a large grain size and a high protein content, though its gluten is better suited to pasta than to raised breads.

Spelt Spelt, Spelt, T. spelta T. spelta became known as became known as d.i.n.kel d.i.n.kel in southern Germany, where it has been grown since 4000 in southern Germany, where it has been grown since 4000 BCE BCE. It's often confused with emmer (farro). Spelt is remarkable for its high protein content, as much as 17%. It's still used to make breads and soups. Central Europeans make Grunkern, Grunkern, or "green kernel," by gently drying or roasting the green grain and milling it for use in soups and other preparations. or "green kernel," by gently drying or roasting the green grain and milling it for use in soups and other preparations.

Varieties of Bread and Pasta Wheats Something on the order of 30,000 varieties of wheat are known, and they're cla.s.sified into a few different types according to planting schedule and endosperm composition. They're mostly used to make breads, pastries, and pastas, and are described in the next chapter. Something on the order of 30,000 varieties of wheat are known, and they're cla.s.sified into a few different types according to planting schedule and endosperm composition. They're mostly used to make breads, pastries, and pastas, and are described in the next chapter.

Wheat Pigments Most wheat varieties have a reddish-brown bran layer that owes its color to various phenolic compounds and to browning enzymes (p. 269) that a.s.semble them into large colored aggregates. Less common are white wheats, whose bran layer is cream-colored due to a much lower content of phenolic compounds and browning enzymes. White wheats have a less astringent taste and discolor less when some of the bran is included in the flour; they're used to replace ordinary wheats when an especially mild flavor or light color is desired. Most wheat varieties have a reddish-brown bran layer that owes its color to various phenolic compounds and to browning enzymes (p. 269) that a.s.semble them into large colored aggregates. Less common are white wheats, whose bran layer is cream-colored due to a much lower content of phenolic compounds and browning enzymes. White wheats have a less astringent taste and discolor less when some of the bran is included in the flour; they're used to replace ordinary wheats when an especially mild flavor or light color is desired.

The color of durum wheat, its coa.r.s.e semolina flour, and dry pasta is due mainly to the carotenoid xanthophyll lutein, which can be oxidized to a colorless form by enzymes in the grain and oxygen. This maturation has traditionally been desired in wheats (remember that the name comes from an ancient root meaning "white"), but is not in durum. Some of the minor wheats are also rich in carotenoid pigments.

Protein Content and Quality of Different Wheat VarietiesGluten quality determines the suitability of a given wheat for particular dishes. Both bread and pasta benefit from a strong, cohesive gluten. Elasticity improves the gas-trapping ability and lightness of bread doughs, but interferes with the rolling of pasta dough into thin sheets.

Wheat Variety

Protein Content, % grain weight Protein Content, % grain weight

Gluten Quality Gluten Quality

Bread

1015 1015

Strong and elastic Strong and elastic

Durum

15 15.

Strong, not very elastic Strong, not very elastic

Einkorn

16 16.

Weak, sticky Weak, sticky

Emmer (farro)

17 17.

Moderately strong, not very elastic Moderately strong, not very elastic

Spelt, hard

16 16.