About Soybeans

Edamame, young soybeans in pods

Soybeans were originally grown in Southeast Asia and domesticated by Chinese farmers around 1100 BC.  By the first century AD, soybean farming had spread to Japan and many other countries.  Soybeans first came to the British Colonies in America in 1765.  Over early U.S. history, soybeans were grown for animal feed.   But in 1904, George Washington Carver, the famous American chemist, discovered that soybeans are a valuable source of protein and oil and also made important contributions to the preservation of good soil.   As a result, cotton farmers began to rotate their crops with soybeans to replenish the soil with nitrogen and minerals from the soybean plants.

Today, 31 states produce and process soybeans.  They are the number two GMO crop grown in the U.S., after corn.  In 2014, a record 3.9 billion (yes, billion) bushels of soybeans will be harvested.   The crop yields about 47 bushels per acre on approximately 74 million acres of land.   Less than one percent (0.2%) of these soybeans are organic.   In fact, organic soybean production peaked in 2001.  Production has stabilized over the last few years to about 125,000 acres with Canada planting another 26,982acres.*  The yield of organic soybeans varies but is similar to conventional GMO soybeans.  The vast majority of the soybean crop is processed for its oil and the remaining pulp is further refined into soy flour or other products or distributed for animal feed.

Mature, dried soybeans

When the FDA issued a health claim in 1999 that 25 grams of soy protein per day (as part of a diet that is low in saturated fat and cholesterol) may reduce the risk of heart disease, the production of soy foods of all kinds exploded.   By 2010, sales of organic soy foods were pegged at $27 billion, according to SPINS, the leading natural product industry sales tracking firm.

Soybeans are a sustainable source of high-quality protein and low saturated fat cooking oil that is high in Vitamin E.  Soybeans contain no cholesterol, little or no saturated fat, plenty of fiber, and Omega-3 fatty acids.  Studies sponsored by the FDA have shown that consumption of soy protein may contribute to a reduced risk of heart disease and can help fight osteoporosis and menopause.  Soy contains isoflavones that have a chemical structure similar to estrogen and offers certain protections against a wide range of diseases, including breast cancer.  Soy has also been shown to help prevent prostate and colon cancer.  

However, soy allergy is also one of the more common food allergies, especially among babies and children.  A majority of children grow out of their soy allergy by age 10, but for those that are still allergic into their adulthood, soy allergies can produce reactions from mild to severe, including anaphylaxis.  People with soy allergies are not necessarily allergic to other legumes, such as peanuts, and vice versa.  But soybeans are widely used in many, many processed food products and so checking labels for ingredients, including soy derivatives, is very important for those who need to avoid soy. The federal Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that all products with an ingredient that is a derivative of soy must contain the word ”soy” on the label.

Products Made from Soybeans

While soy has the highest amount of protein among beans, the whole bean form (in its mature state) is sometimes hard to digest and takes the longest time to cook.  For the most part, Americans consume soy in a wide variety of processed foods.

Edamame – Edamame soybeans are harvested when the beans are still green and sweet tasting.   These are the main way that whole soybeans are served in the U.S.   After boiling in slightly salted water for 15 to 20 minutes, they are often served as a snack or a main vegetable.  They are eaten by biting on the pod and squeezing out the round, green beans.  The pods are discarded.  They are high in protein and fiber and contain no cholesterol.  Edamame is merchandised either shelled or in the pod in the produce or freezer section of the store.  Edamame beans (without the pods) are also excellent additions to soup, salads, pilafs, and other grain dishes.

Meat Alternatives – There are many meat alternative products containing soy protein or tofu that are made to imitate meat, such as burgers, sausages, bacon, and hot dogs.   Generally, they are cholesterol-free and lower in fat than meat and good sources of protein, iron, and B vitamins.

Miso – Miso is a traditional Japanese fermented food that is prized for its rich, complex flavor and its dense concentration of nutrients and disease-fighting properties.  Miso is made from a fermented paste of soybeans, along with other ingredients.  Fermentation takes place through the use of koji.  The color, flavor, and saltiness of the miso depend on the variety of raw materials and the length of time of fermentation.   The most popular varieties of miso include hatcho (made with soy only), genmai (made with soy and brown rice), kome (made soy and white rice), mugi (made with soy and barley), natto (made with soy and ginger) and soba (made with soy and buckwheat). 

Why This Matters:

Miso is not only soybeans – often it contains other grains including grains that have gluten.  It is very important that customers on gluten-free diets read the labels of miso carefully so they can be assured they are purchasing miso only made with wheat & gluten-free ingredients.

The fermentation process breaks down the oils, proteins, and carbohydrates into forms more easily digested by the human body.  In addition, the finished miso contains live lactobacilli which help the body to extract nutrients from foods and increases the concentration of beneficial bacteria in the digestive tract.  Nutrients in miso include vitamins B2, K, calcium, iron, potassium, choline, and lecithin.  It is also high in dietary fiber and provides a large amount of complete protein.  It is especially high in polyunsaturated fats, including linoleic acid.

Natto – Natto is fermented soybeans, eaten mostly in Japan and considered the "breakfast of champions".  It has a pungent smell and viscous texture that usually demands an acquired taste.  Research is now showing that natto may offer potential health benefits including the ability to reduce the risk of blood clots.

Soy Cheese – Many cheese substitutes for animal milk come from soy including cheddar, mozzarella, Monterey jack, parmesan, American, and various flavors of alternative cream cheeses.  Many of the soy cheeses on the market include casein or calcium caseinate, lecithin, or other gums intended to give the texture of cheese.  Some are fortified with additional vitamins and minerals.  Most soy cheeses have attributes similar to regular cheese and can be sliced or grated.  They are a good alternative for people who are vegan or allergic to milk or lactose.  But if a customer has an allergy to casein, they need to avoid those items and should read the labels carefully.

Soy Flour – Soy flour comes from ground mature soybeans.  It boosts protein, adds moisture to baked goods, and is the basis for some soymilks and TVP (textured vegetable protein).  Soy flours can come in full-fat (contains all the natural oils), low-fat (reduces the oil by about one-third), and non-fat or defatted, which removes almost all of the oil during processing.  Soy flour also provides dietary fiber and other nutrients including isoflavones, minerals such as iron, B vitamins, and potassium.  It has a yellow color and a strong flavor that can be mellowed with toasting.  Toasted soy flour is sometimes called soya flour.

Soy Milk – Soy milk is made by cooking soybeans, grinding them, and then separating out the insoluble fiber.  Soy milk has about the same amount of protein as cow milk, but less fat and calcium. Some soy milks are fortified with calcium and additional vitamins.  Soy milks are sold plain and flavored (vanilla & chocolate, sweetened and unsweetened) as a fresh refrigerated product or in shelf-stable aseptic cartons.  Soy milk is widely used as a beverage by people who are adverse to or allergic to cow milk. It can also be used in cooking and baking in place of cow milk.

Soy Sauce, Shoyu, Tamari, and Teriyaki – Soy sauce is one of the world's oldest condiments and has been used in China for more than 2,500 years. It is made from fermenting a mixture of mashed soybeans, salt, enzymes, and in some cases, other grains such as wheat. The traditional, natural fermentation method takes up to six months to complete and results in a transparent, delicately colored broth with balanced flavor and aroma.  On the other hand, conventional soy sauce is also made through a chemical process known as acid hydrolysis.  These non-brewed sauces take only two days to make and are often opaque with a harsh flavor and a chemical aroma.

Why This Matters:

Until the 1960s, the only type of soy sauce in the U.S. was the mass-produced, commercial type.  In the mid-1960s, George Ohsawa, father of the macrobiotic diet, introduced the natural, Japanese product to North America, but it was often inaccurately labeled as tamari.  In fact, true tamari is relatively rare in the U.S. (except in natural food stores) and often consumers are buying a tamari/shoyu combination, not the true wheat-free tamari.  Only true tamari is wheat-free and suitable for gluten-free diets.  Often tamari is made in the same facility that makes soy sauce, which contains gluten.  It is very important that customers and store staff check the label on the tamari products to assure there is no wheat or wheat contamination.

In Japan, soy sauce is known as shoyu and is made from whole soybeans, salt, water, and wheat koji. It is allowed to age for a year or two.  Shoyu flavors can vary but the best have a full mellow flavor. The flavor can be lost during cooking so it best to add shoyu (and tamari) at the end of cooking.

Tamari, the wheat-free soy sauce, is made with soybean koji instead of wheat koji.  It has a distinctive aroma as well as a thicker texture, deeper color, and stronger taste than traditional soy sauce.  Where shoyu (regular soy sauce) is used as an all-purpose sauce for cooking and seasoning, tamari is often used for dipping or sautéing.   

Teriyaki sauce is a mixture of soy sauce, sake (or mirin), ginger, and sugar.  It is a basic marinade commonly used in Japanese cooking.  Most commercial teriyaki sauces will include gluten since the soy sauce used is from both soybean and wheat.  There are some brands of gluten-free teriyaki sauce.  Customers and store staff should look carefully at labels and ingredients if they are on a gluten-free diet.

Tempeh – Tempeh has been a favorite staple protein food in Asia for hundreds of years. William Shurtleff and Akiko Aoyagi, authors of The Book of Tofu and The Book of Tempeh are credited for introducing Tempeh to the U.S. in the 1960s.  Tempeh is made by adding a culture to partially cooked soybeans and incubating them at 88° F. for 28 to 32 hours. The result is a fermented product that is typically formed into a patty, with black veins and a mushroom-like aroma.

Tempeh can be made from just soybeans or from soybeans plus other grains, legumes, or sea vegetables.  Barley is a popular grain used along with soy to produce tempeh.   Tempeh is a concentrated source of protein:  four ounces of tempeh contains 24 grams of protein, as much as in 3 eggs or 3 ounces of meat.  Tempeh has a bitter taste if eaten raw so it is usually cooked.  Like tofu, tempeh absorbs flavors from marinades and other foods very easily and is often used in stir-fries, simmered in barbecue sauce, or in sweet and sour sauces.  Tempeh is denser and chewier than tofu and works well for marinating and grilling. 

Why This Matters:

Tempeh and tofu are important vegan and vegetarian staples in natural food stores.  It is important that store staff understand the differences between the two products and how they are used in different ways for meal preparation.

Textured Vegetable Protein (TVP)

Textured vegetable protein (TVP), also known as soy meat, or soya chunks, is a defatted soy flour product sold in granular or chunk form.  It is often used as a protein replacement for meat and is used as a substitute to meat or to extend the ground meats in various dishes.  It is quick to cook and has protein equivalent to meat.  Some varieties of TVP contain salt, flavorings, and other additives, so it is very important that customers review the labels.  It is usually sold as a dehydrated product that must be rehydrated before using, but it can also be found as a prepared frozen product made to resemble ground beef. 

Tofu – Tofu has been a staple protein food in parts of Asia for over 2,000 years.  It is a bean curd made from soy milk that is manufactured similarly to how cottage cheese is made from cow’s milk. A coagulating agent is added to soymilk and the curds are pressed into blocks.  Common coagulating agents are nigari, a liquid derived from evaporated seawater that contains several minerals including magnesium chloride, magnesium sulfate, calcium sulfate, potassium chloride, and magnesium bromide.  In the US, a refined salt (magnesium chloride or calcium chloride) is often used instead of nigari. If calcium sulfate is used the calcium content of the tofu will be significantly higher.

Tofu is produced with varying amounts of water content to make extra firm, firm, or soft products. Silken tofu (Mori-Nu is one example) uses a completely different coagulant, gluconolactone, to give it a uniquely soft and silky texture.  Firm tofu is best for stir-fries, marinated grilled or baked tofu, or any recipe where the tofu needs to hold its shape. Soft and silken tofu works best for blended items like puddings and cream pies.

Tofu is bland and easily absorbs flavors from marinades and sauces. This trait makes tofu a very versatile food used in both sweet and savory dishes.  Tofu can also be frozen and then thawed and drained. This process dramatically changes the texture of the tofu.  One-half cup of firm tofu contains 10.1 grams of protein with only 94 calories and 5 grams of fat, so it is an excellent source of vegetarian, low-fat protein.  There are both organic and non-organic tofu products on the market and many of the organic is also non-GMO.  In natural food stores, Nasoya and Mori-nu are two organic tofu brands.

*Data is from 2008



Words to Remember


A protein produced from casein in milk. It is commonly used in the food industry in powders that require rapid dispersion in water. Bodybuilders may use calcium caseinate protein because it breaks down more slowly than whey protein, providing a more sustained release of amino acids.



Polyphenolic compounds that can produce estrogen-like effects on the body. They are classified as phytoestrogens. Legumes, particularly soybeans are the richest sources of isoflavones in the human diet.



Rod-shaped bacterium that produces lactic acid from the fermentation of carbohydrates. Lactobacilli are also "friendly" bacteria that normally live in the human digestive, urinary and genital systems without causing disease. Lactobacilli are used to treat IBS, Crohn's disease, colon inflammation, urinary tract infections, vaginal yeast infections, for certain skin disorders, and in some cases, for high cholesterol, lactose intolerance, hives and to boost the immune system.



Essential fat in humans, it is found in many foods including soybeans and egg yolks. It is used in medicines and also as a food additive to keep ingredients from separating.



Polyunsaturated fatty acid (omega-6).