Real Food Encyclopedia | Soy Milk

Soy milk’s popularity has waned in recent years with the rise of other alternatives to cow’s milk — like almond, oat and hemp — and soy’s increasingly negative image. What are the environmental and health impacts of soy milk? And how is it made? Spoiler: It’s super easy to make at home — without all of the additives and sugar in commercial soy milk — and we’ve got the video to prove it.

Soybeans (Glycine max) are thought to be native to China, where they have been cultivated for at least 3,000 years, but recent data shows that there may have been several points of domestication in East Asia (including northern China, Japan and Korea), some dating back as far as 5,500 years ago.

Soybean cultivation was documented as early as the late 18th century in the U.S., when, according to “The Oxford Encyclopedia of Food and Drink in America,” the seeds were brought back from China. Soy was mainly used as forage for animals, which remains the case in the U.S. today, but soy products like soy milk and tofu are increasing in their popularity

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Did you know?

  • The skin that forms when making homemade soy milk is used in a variety of recipes in China and Japan. In Japanese, the skin is called yuba — and you can make your own at home.
  • Roasted soybeans were used as a coffee substitute during the Civil War.

What to look for when buying soy milk

Commercial soy milks are usually treated to remove some of the soy bean’s characteristic “beany” flavor. This is done through processing and by adding sugar and flavorings (like chocolate and vanilla). Commercial soy milk is also often artificially thickened to enhance the “mouthfeel” of the product — that is, to make the drink feel more like whole cow’s milk.

Sustainability of soy milk


According to the USDA, nearly 100 percent of all soy acreage planted in the U.S. is genetically modified (GM) to be herbicide-tolerant (HT), up from only 17 percent in 1997. HT soybean plants, developed by the agricultural giant Monsanto (now owned by Bayer), can withstand herbicides that are used to control weeds — namely Roundup (glyphosate), also originally developed by Monsanto. Unfortunately, the increased use of glyphosate has resulted in “superweeds” that are just as resistant, in some cases necessitating the use of different herbicides and mechanical tilling. Glyphosate has also been connected to cancer.

Environmental impact

Soy just surpassed corn as the largest cash crop in the U.S. What happens to all of it? A whole lot of soybeans are pressed into oil, much of which is hydrogenated or partially hydrogenated and used in processed foods or for frying. Much non-organic soybean oil is extracted using hexane, a chemical that has been linked to negative neurological effects. The “soy meal” — what is left after pressing the beans for oil — is frequently used for industrial livestock feed in concentrated animal feeding operations (or CAFOs).


Soy milk’s water footprint is significantly smaller than cow’s milk’s. One glass of cow’s milk requires about 67 gallons water to produce, whereas one glass of soy milk needs about 18.

Using soy milk


Commercial fresh soy milk has a shelf life of about a week to ten days; shelf-stable soy milks are also available. Homemade soy milk has a shorter shelf life because it is free of stabilizers, preservatives and sugar, and will last for no more than five days in the refrigerator.


Soy milk can be used as a substitute for cow’s milk in many recipes, including in baked goods, sauces, smoothies, milkshakes, ice creams, puddings and custards. There is also an increasing variety of soy milk yogurts on the market — but you can always make your own soy yogurt from homemade soy milk. Of course, soy milk can also be poured on cereal or stirred into coffee and tea.

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In general, soy is good source of protein: One cup of soy milk represents about 13 percent of your daily needs. Commercial soy milk is high in Vitamin D, Vitamin B12, riboflavin, calcium and copper and even contains some iron. Soy milk is also far lower in saturated fat than whole cow’s milk.

Soy milk, unlike cow’s milk, is lactose-free, which means those with lactose intolerance can consume it without ill effects. Soy has gotten a bad rap in the press in recent years for containing supposed “feminizing” hormones; however, research is still inconclusive about soy products’ hormone-like effects on the body. Commercial soy milks often contain various stabilizers and thickeners (like carrageenan, which has itself come under fire in recent years for potentially causing gastrointestinal inflammation and other health issues) and often lots of sugar. Plus, since the vast majority of soy is GM, any non-organic soy milk will be produced from GM soy. If you’re concerned about any of these issues, look for organic, unsweetened soy milk — or make your own.

Top photo by Stock.