Soybeans (Glycine max) are a species of legume. Immature soybeans are called edamame. Soybeans belong to the the family Fabaceae, along with common beans (green snap beans, pinto beans, heirloom beans, Great Northern beans, black turtle beans, kidney beans, and navy beans), edible-pod and mature peas, fava beans, black-eyed peas, jicama, adzuki beans, lentils, lima beans, peanuts, chickpeas, carob, and licorice. The family also includes broom, gorse, and kudzu.

Soybeans were first domesticated in the eastern half of north China in about the 11th century BC (early Chou dynasty). After the 7th century BC, soybeans spread from their primary gene center in China. By the first century AD, they had probably reached northwest, central, and south China, along with Korea and Japan.

T’ao Hung-ching (451-536) was a Chinese physician and herbalist. His version of the Pen-ts’ao herbal written in 500 AD describes the medicinal properties of soybeans as a remedy for proper functioning of the heart, liver, kidney, stomach, and bowels. They were used to stimulate the lungs, eliminate toxins from the system, improve the complexion by cleansing the skin of various impurities, and stimulate the growth and appearance of hair. In addition, fresh green soybeans (edamame) were used to cure edema, typhoid fever, bladder trouble, circulation problems, and chills, among other ailments.

Li Shih-chen (1518-93) was a later Chinese physician and herbalist. He wrote the Pen-ts’ao Kangmu herbal in 1597, which repeats T’ao Hung-ching’s claimed medicinal properties of soybeans. The earliest known description of a soy product by a European was also in 1597, when Francesco Carletti, a Florentine visiting Nagasaki, Japan, described “misol” (miso).

In 1670 Dutch traders started to import Japanese shoyu (soy sauce) to France at the request of Louis XIV, who used it as a seasoning at his banquets. The philosopher John Locke mentioned that soy sauce, imported from the East Indies, was available at a particular restaurant in London in 1679. In 1688, English explorer William Dampier described soy sauce in Japan. German scientist Englebert Kaempfer studied the manufacture of shoyu and miso in Japan from 1690 to 1692. In 1696, English cleric John Ovington, praised the flavor of soy sauce in western India. From the late 17th century, soy sauce was a common item of trade from East Asia to England, and perhaps the Netherlands.

In 1712, Kaempfer published Amoenitatum Exoticarum (Exotic Novelties), which included the earliest known European description and illustration of a soybean plant. It described how shoyu and miso were made from soybeans in Japan. Soybeans grew as a curiosity in botanical gardens in the Netherlands by 1737 and in France by 1740. By the mid-18th century, soy sauce was widely used in England and had started to become popular in British colonies in America. In 1764, Swedish captain Carl Gustaf Ekeberg wrote an article about Chinese soy sauce.

Samuel Bowen of colonial Georgia traveled to London around April 1766 and returned to Savannah in November of the same year. On July 1, 1767, Bowen received a patent, number 878, for his “new invented method of preparing and making sago, vermicelli and soy from plants growing in America, to be equal in goodness to those made in the East lndies.” During 1770-75, Bowen exported to England 1,058 quarts of soy sauce that he had made in Georgia. In 1775 the Swedish botanist Carl Peter Thunberg wrote about Japanese shoyu and miso. Soybeans grew in botanical gardens in England by 1790, and by the late 18th century, soy sauce started to be used as the basis for many table sauces in that country. 

In his article titled “Soy” in the 1804 edition of The Domestic Encyclopedia by A.M.F. Willich, James Mease wrote: “Soy, or Sooju, is a species of liquid condiment, which is imported from India, and is used as a sauce…It is prepared from the leguminous fruit of the Soja (Dolichos soja , L.) a native of Japan…Soy possesses a strongly saline taste, but has only a slightly aromatic flavor; it is chiefly used at the tables of the luxurious…The Soy-bean bears the climate of Pennsylvania very well. The bean ought therefore to be cultivated.”

In 1821, the first European soybean culture tests were performed in France. John Wheeley Lea and William Henry Perrins, dispensing chemists from Broad Street, Worcester, introduced a sauce in 1838, which was allegedly based on an old Indian recipe, and included vinegar, molasses, anchovies, sugar, salt, tamarind extract, onions, garlic, cloves, soy sauce, lemons, pickles, and peppers. In 1840 soybeans first started to be grown on farms in Italy. Soy sauce continued its growth in popularity throughout the 19th century, especially in England, where it was used increasingly in many spiced table sauces, the most popular of which was Harvey’s (which reached its peak of popularity after 1850) and Lea & Perrins. In 1851, soybeans were planted in Illinois. Starting in 1854, when the French Society for Acclimatization received the first samples of soybeans from a French consul in China, the Society began to distribute packets of soybeans to its members throughout France, to encourage their acclimatization and propagation.

In 1855, T.V. Peticolas of Mount Carmel, Ohio, wrote to The Country Gentleman concerning soybeans: “When eaten a few times they are pleasant enough, but have very little flavor–better when mixed with other beans. Before cooking they must be soaked at least 24 hours. They are inconvenient to use green, being difficult to hull.” This was the first mention of any American eating boiled soybeans and edamame. That same year, French sinologist Stanislas Aignan Julien described soy nuggets. In 1857 an editorial in the American Agriculturalist said of soybeans: “Mr. Thos. R. Joynes, Jr., of Accomac, Va., writes . . . As for the eating qualities, I can only say, that I have just risen from the table at which I made my first trial of them, and I want nothing better. They make a rich and most excellent dish–inferior to no bean or pea I have ever seen.”

In 1866, the Frenchman Paul Champion, who traveled to China, described soy milk and yuba. Between 1873 and 1878,  Dr. Friedrich Haberlandt of Vienna initiated hundreds of successful soybean culture tests throughout southern central Europe. His book Die Sojabohne , published in 1878, reported in detail on his work with soybean culture in Europe and discussed many European applications of soy products. In 1879, George Cook of Rutgers University in New Jersey, included a translation of an article on soybeans from Munich, which mentioned food uses: “. . . a plant whose pleasant-tasting seeds are rich in albumen and fat, in very digestible forms . . . Its seeds, boiled or roasted, have a pleasant taste, and form an almost daily part of the food in India, China, and Japan.” This was the first U.S. mention of roasted soynuts. In 1880 Vilmorin-Andrieux & Co. first offered soybeans for sale in their seed catalog. By that decade, Lea & Perrins sauce had become known as Worcestershire sauce.

Soybeans flourished in the hot, humid summer weather characteristic of the American South. In 1882, Dr. Charles W. Dabney, Jr., of the North Carolina Agricultural Experiment Station, in the longest and most detailed US report on soybeans to date gave a recipe for vegan mashed potatoes: “Prof. Hecke of Vienna highly commends a dish prepared by boiling these beans and potatoes separately, mashing them, mixing one part of the beans with two of the potatoes and seasoning to taste. He thinks that the beans contain so much fat, that no milk or butter needs to be added to this dish.” In 1891 Charles Christian Georgeson of the Kansas State Agricultural Experiment Station described edamame: “Sometimes (the beans) are eaten green when nearly full grown; they are boiled in the pods and shelled at the meal.”

By the turn of the 20th century, the United States Department of Agriculture was conducting tests on soybeans and encouraging farmers to plant them. In 1904, American chemist George Washington Carver discovered that soybeans are a valuable source of protein and oil. He also realized the role soybeans played in enriching soil. Carver encouraged cotton farmers to rotate their crops in a three-year plan so that legumes like peanuts and soybeans would replenish the soil with nitrogen and minerals for two seasons, so that cotton could grow in the third year. This crop rotation produced a far better cotton crop than the farmers had seen for many years.

At the end of the Russo-Japanese War in 1905, after the troops were withdrawn, Manchuria found itself with a surplus of soybeans and needed to find a new market. At the same time Europe’s traditional main oil seeds, cottonseed and linseed, were in short supply and therefore very expensive. In 1907 Japanese traders sent the first large trial shipment of Manchurian soybeans to England, where they were crushed in English oil mills at Liverpool and Hull to make oil and meal. American farmers began shipping soybeans to Europe around 1908. That year, the UK imported and crushed 40,600 metric tons of soybeans from Manchuria. After that, imports skyrocketed, reaching a peak of 449,000 metric ton imported and crushed in 1910.

In 1919 William Morse co-founded the American Soybean Association and became its first president. Morse spent two years gathering soybeans in China, and in 1929, he brought back more than 10,000 soybean varieties for agricultural scientists to study. 

At Henry Ford’s research facility, scientists made a plastic out of soybeans strong enough for the gearshift knobs, horn buttons, window frames, accelerator pedals, light-switch assemblies and ignition-coil casings. By 1935, Ford was using one bushel of soybeans for every car he manufactured. On August 13, 1941, Ford unveiled a car whose body was made of soybean plastic. It was 1,000 pounds lighter than a steel car.

Prior to World War II in Europe and the United States, many people ate meat only once a week or so. During this pre-war period, the U.S. imported more than 40% of its edible fats and oils. Disruption of trade routes during the war resulted in a rapid expansion of soybean acreage in the U.S. as the country looked for alternatives to imports. When the United States entered the war, the steep increase in demand for oils, lubricants, plastics, and other products greatly increased the demand for soybeans, which American farmers met. Soybeans were successful as a new crop because there was an immediate need for soybean oil and meal, their culture was similar to corn, and they benefited other crops in a rotation. Following World War II, soybean production moved from the southern U.S. into the corn belt of the mid-west.

Starting in 1945, European imports of soybeans, soy oil, and soy flour increased dramatically, but the main source of these imports was the U.S. rather than East Asia.

During this post-war period, the United States experience a period of increasing prosperity. In the summer of 1948 Dr. A.K. Smith of the USDA Northern Regional Research Center at Peoria, Illinois, visited China to study soy products, visiting Shanghai, Beijing, Tianjin, Nanjing, Hangzhou, and Guangzhou (Canton). His book, Oriental Methods of Using Soybeans as Food (1949), contained information on the Chinese diet and traditional Chinese methods for making soy sauce, soy bean sprouts, sweet wheat-flour miso (tian mian jiang), soymilk, tofu, fermented tofu, and soy nuggets. He noted that 90% of the Chinese people were farmers, 25% of the land was arable, and farms averaged 5-7 acres in size. The dense population flourished on a largely vegetarian diet. The peasants ate meat only three times a year, on their three great holidays: Dragon Festival, Autumn Festival, and New Year. Roughly 95% of the protein in the Chinese diet came from plant sources (versus 45% at that time in the U.S.) and 88% of all Chinese food consisted of cereal grains and legumes, with only 3% meat and eggs and less than 0.1% milk. The basic diet of north China consisted of 40% each corn and millet and 20% soybeans. Smith concluded: “China gives a wonderful illustration of the effects on the human race of a vegetarian diet over a long period of time . . . and could no doubt serve as a source of valuable nutritional data.”

Between 1949 and 1954 the American Soybean Association (ASA), in conjunction with the Economic Cooperation Administration, the Marshall Plan, and the US Foreign Agricultural Service (FAS) began intensive market development efforts for soybeans and soybean products in Europe. Unfortunately, in post-war America, people associated prosperity and improved nutrition with meat consumption. Starting in the 1950s in America, farmers wastefully processed tens of millions of tons of soybean meal each year through the digestive tracts of chickens, turkeys, cattle, and hogs.

The U.S. dominated world soybean production for three decades starting in 1950, growing more than 75% of the world soybean crop. In 1956 the Soybean Council of America, a newly established trade association under the ASA and the US National Soybean Processors Association, signed a contract with FAS for market development work in Spain and Italy. In 1958 the Council opened a European office in Rome. European soybean imports from the U.S. increased very rapidly, and total soybean imports grew by 25% a year. The macrobiotic movement also spurred production of soy foods (especially miso and shoyu) in Europe in the late 1950s.

After about 1960, European meat consumption also increased dramatically, following the wasteful American model of processing soybeans through animals. Imports of soy oil and soybean meal also increased rapidly.

In the early 1970s, large-scale soybean production began in several South American countries, most notably Argentina and Brazil. By 1972, up to 20% of European soybeans were imported from Brazil and Argentina.

In 1973 a projected shortage of soybeans caused the U.S. government to place a partial embargo on exports. This led European farmers to try to reduce their heavy dependence on U.S. soybeans, in part by growing more soybeans in Europe. In the U.S., soy foods became increasingly popular starting around 1976. Soy oil became the leading oil in Europe; by 1978 its consumption was greater than that of the next three leading oils combined.

By 2003, the U.S. share of the world’s soybean production had shrunk to 34 percent, while Argentina’s and Brazil’s had increased to 18 and 28 percent, respectively. 

Thirty-one U.S. states have a soybean production industry. The top producers are the states of Iowa, Illinois, Indiana, and Minnesota.  These mid-western states have deep, rich soils and relatively cool summer nights.  North Carolina produces about one-tenth of the volume of soybeans produced in Iowa.

Edamame can:

1. Help you maintain a healthy weight. Edamame is high in protein and low in fat. A 100-gram serving of cooked edamame beans (about 2/3 cup) has 22% of the Daily Value (DV) for protein, along with 21% of the DV for fiber. These nutrients help you feel full and keep you satisfied. The same serving contains just 8% of your DV for fat, 6% for calories, and just 3% of the DV for carbohydrates. Genistein in soy may also help you maintain a healthy weight.
2. Promote cardiovascular health. The folate in edamame helps prevent homocysteine build-up in your blood, which in turn decreases your risk of heart attack. The vitamin K in edamame helps prevent calcification of your arteries. Edamame is also a rich source of both types of fiber, soluble and insoluble, but it’s particularly rich in soluble fiber, which may help improve your blood sugar and cholesterol levels. Soluble fiber is particularly effective at lowering low-density lipoprotein (LDL or “bad”) cholesterol levels. The copper in edamame also plays a role in keeping your blood vessels healthy. Phosphorus, along with magnesium in edamame, helps maintain a healthy heartbeat. Magnesium, along with potassium, helps regulate blood pressure. Saponins in soybeans lower blood cholesterol and decrease risk of cardiovascular disease. Omega-3 fatty acids, including alpha-linolenic acid (ALA) in soy can protect against cardiovascular disease, lower blood pressure, reduce the risk of heart attack, and reduce the risk of sudden cardiac death in people who already have heart disease. Glycitein in soy has weak estrogenic activity and may fight atherosclerosis.
3. Fight free radicals. Manganese in edamame is a co-factor for the antioxidant enzyme, superoxide dismutase. Antioxidants neutralize free radicals, helping to prevent cell and tissue damage that could lead to heart disease, cancer, and other diseases. The vitamin C in edamame functions as an antioxidant and prevents oxygen-based damage to your cells. It also helps prevent cancer by neutralizing volatile oxygen free radical molecules and preventing damage to your DNA that can lead to cancer and by destabilizing a tumor’s ability to grow under oxygen-starved conditions. Inositol (phytic acid) in edamame may retard cell growth and work as antioxidant. Saponins in soybeans prevent cancer cells from growing and mutating and neutralize free radicals to prevent disease. Genistein in soy acts as an antioxidant and anti-cancer agent. Daidzein in soy protects cells against oxidative damage to DNA, reduces incidences of prostate cancers, works with tamoxifen to protect against breast cancer. Glycitein in soy may fight oxidative damage and cancer.
4. Maintain strong bones. Folate in edamame helps prevent osteoporosis-related bone fractures. Manganese facilitates formation of bone. The vitamin K in edamame helps protect your bones from fracture and helps prevent postmenopausal bone loss. Copper, phosphorus, and magnesium are important for maintaining strong, healthy bones. Potassium maintains the density and strength of bones by decreasing urinary calcium loss. The vitamin C in edamame helps produce collagen, which supports strong bones and helps you absorb calcium. Saponins in soybeans protect against bone loss. Genistein in soy protects against osteoporosis. Daidzein in soy seems to reduce the risk for osteoporosis by stimulating the formation of osteoblasts. Glycitein in soy may fight osteoporosis.
   
5. Support your immune and nervous systems. Like all legumes, edamame is loaded with nutrients, including folate, copper, phosphorus, magnesium, iron, potassium, and thiamine. Together, these nutrients contribute to a better immune and nervous system. The folate in edamame supports your immune system and allows your nerves to function properly. The copper and magnesium in edamame also plays a role in keeping your immune system healthy. Phosphorus and potassium in edamame help regulate nerve transmission. Iron helps generate T lymphocytes, white blood cells often referred to as T cells, which play an important role in immune function. Iron also helps generate hypochlorous acid, a beneficial reactive oxygen species that white blood cells use to kill pathogens. The thiamine in edamame is important for a nervous system function and energy metabolism. The vitamin C in edamame supports your immune system, processes toxins for elimination, and acts as an antihistamine. Edamame contains a high concentration of the phytoestrogens genistein and daidizein, compounds that mimic the behavior of estrogen in the body and may be able to lower your risk of certain types of cancer. Saponins in soybeans stimulate your immune system by increasing the production of antibodies, fight bacterial and fungal infections, and increase the effectiveness of certain vaccines.
6. Eliminate toxins. Molybdenum in edamame helps in eliminating toxic substances, including purines, sulfites, and drugs. It also helps in metabolizing fats and carbohydrates, mobilizing iron from your liver, which can prevent anemia, and preventing tooth decay.

Nutrients in 100 Grams Frozen Edamame, prepared

Nutrient	Amount	Daily Value
folate	311 µg	78%
manganese	1 mg	51%
vitamin K	26.7 µg	33%
protein	10.9 g	22%
fiber	5.2 g	21%
copper	0.3 mg	17%
phosphorus	169 mg	17%
magnesium	64 mg	16%
thiamine	0.2 mg	13%
iron	2.3 mg	13%
potassium	436 mg	12%
molybdenum	8.26 µg	11%
vitamin C	6.1 mg	10%
riboflavin	0.2 mg	9%
zinc	1.4 mg	9%
fat	5.2 g	8%
calcium	63 mg	6%
Calories	122	6%
vitamin B6	0.1 mg	5%
niacin	0.9 mg	5%
pantothenic acid	0.4 mg	4%
carbohydrates	10.2 g	3%
sodium	6 mg	0.2%
cholesterol	0 mg	0%

Fresh, raw soybeans are found in the produce and frozen foods sections of Asian, natural food and some grocery stores. You might find fresh edamame pods at farmer’s markets or Asian groceries in late summer. Some home gardeners plant edamame as well. Firm, deeply green, unbruised pods will produce the best quality beans when shelled. Alternatively, frozen edamame is available year round.

Try to cook fresh edamame pods as soon as possible after purchasing. you can store them for a day or two in the refrigerator before cooking.  Keep frozen edamame for up to three months.

Unlike regular mature soybeans, which become dry and brown, beans inside edamame pods are unripe, still soft, green, and edible. They require just a few minutes of cooking. Only the beans are to be eaten because the outer pod is too fibrous.

Frozen edamame beans have already been cooked and just need to be reheated for 2 to 3 minutes in a pan of boiling water.

Cook the whole pod, because it’s difficult to remove the beans prior to cooking; they slip out easily once the pods are cooked. To cook fresh edamame pods:

1. Bring a pot of water or lightly salted water to boiling in a large saucepan. Add the pods and return the water to boiling; boil pods about 5 minutes. Do not overcook them or they will get mushy.
2. Drain the beans and cool them under cold running water or immerse them in ice water to stop the cooking.
3. To shell the beans, gently squeeze the pods with your fingers to release them. Or have fun simply putting the pods in your mouth and popping the beans out of their skins.

Some people serve edamame cold and will refrigerate the cooked beans for an hour or two after cooking. Cooked edamame pods will keep in the refrigerator for up to several days. Freezing is another option — you can freeze whole cooked pods, or shell the beans and freeze them. To reheat the frozen beans, cook them in boiling water for a few minutes.

Either way, you may want to sprinkle them with a coarse salt, soy sauce, or a favorite seasoning as an appetizer or side dish, or serve the beans in salads, stir-fries, and dishes with grains. Some people describe the taste as nutty and buttery, with its own unique flavor. Edamame makes a creamy hummus-style dip, and is a and nutritious garnish for soups and entrees.