Soy milk’s popularity has waned in recent years with the rise of other alternatives to cow’s milk – like almond and hemp milks – 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 recipe (and video) to prove it. Read on for everything you’ve ever wanted to know about soy milk.
A Brief History
Soybeans 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. According to researchers at Washington State University, the first written record of soybeans comes from China, around 200 BCE; the beans were apparently used medicinally. The Oxford Companion to Food notes that soy milk has been enjoyed by the Chinese since ancient times. It is thought that the Chinese introduced soy to Japan, where it became, and remains, quite popular.
Soybean cultivation was documented as early as the late 18th century in the US, when, according to the Oxford Encyclopedia of Food and Drink in America, the seeds were brought back from China in 1765. As is the case today, soy in the US was mainly used as forage for animals, but soy products like soy milk and tofu are increasing in their popularity.
- 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 – Bon Appetit shows you how to make your own yuba at home.
- Roasted soybeans were used as a coffee substitute during the Civil War.
- Cow’s milk alternatives, like soy milk and almond milk, represent the fastest-growing segment of the dairy market, according to the Washington Post.
Cultivation and Production
Soybeans (Glycine max) are in the Fabaceae (legume) family, along with peas, beans, alfalfa and peanuts. Soybeans grown to make soy milk and other soy products (like tofu and soy sauce) are harvested when mature – this basically means that the beans are allowed to mature and dry in their pods. Soybeans grow similarly to bush beans – they require warm soil and produce fairly bushy, upright plants that can grow as large as three to four feet tall. The US, Brazil, Argentina and China are the top worldwide producers.
According to the USDA, in 2014, 94 percent of all soy acreage planted in the US 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, are resistant to herbicides that are used to control weeds – namely Roundup (glyphosate), an herbicide originally developed by…you guessed it: Monsanto. Unfortunately, the increased use of glyphosate has resulted in “superweeds” resistant to the herbicide, in some cases necessitating the use of different herbicides and mechanical tilling.
Soy, just following corn, is the second largest cash crop grown in the US, with over 84 million acres planted in 2014. What happens to all of this soy, you ask? A whole lot of soybeans are pressed into oil, much of which is hydrogenated or partially hydrogenated (read: loaded with heart unhealthy transfat) and used in processed foods and for frying. Much non-organic soybean oil is extracted using hexane, a chemical that has been linked to negative neurological effects. The remaining “soy meal” – what is left after pressing the beans for oil – is frequently used for industrial livestock feed in concentrated animal feeding operations (CAFOs).
Soy milk's water footprint is significantly less than cow's milk's. Our resident food waste and water footprint expert, Kai Olson-Sawyer, using data from Water Footprint Network, calculated that one glass of cow's milk requires about 67 gallons water to produce, whereas one glass of soymilk needs about 18 gallons of water. (And one gallon of cow's milk equals about 1,010 gallons of water versus only 270 gallons of water for each gallon of 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.
In general, soy is good source of protein – one cup soy milk represents about 13 percent of your daily protein needs. Commercial soy milk is high in Vitamin D, Vitamin B12, riboflavin, calcium, 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 grown 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! (See recipe, below.)
Video: Homemade Soymilk
What to Do with It and Cooking
Soy milk can be used as a substitute for cow’s milk in many recipes, including in baked goods, sauces, smoothies, milkshakes, 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, it is also used as a substitute for cow’s milk in all the ways Americans use milk – like in cereal, stirred into in coffee and tea, and churned into ice cream.
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 (which acts as a preservative), and will last for no more than five days in the refrigerator.
Recipe: Homemade Soy Milk
Homemade soy milk is easier to make than you’d think – all you need are dried soybeans and water. The resulting liquid can be enjoyed hot or cold, and can be used for baking and making tofu. And don’t waste the leftover pulp (called okara) – you can use it in veggie burgers or in baked goods. (Here’s a whole blog dedicated to recipes made with okara.)
1 cup organic dried soybeans
8-9 cups water
- Rinse the soybeans.
- Soak the soybeans in 3 cups of water for a minimum of 12 hours.
- Combine the soybeans with soaking water in a blender. Blend the soybeans with water on high speed until well-mixed and very smooth. (Depending on the size of your blender, you may have to do this in batches.)
- Pour the blended mixture into a large pot and add 5-6 cups of water (*see note, below).
- Cook the mixture over medium heat, stirring occasionally, for 10 minutes.
- Place a length of cheesecloth (doubled) or a straining bag over a clean, medium pot.
- Strain the mixture through the cheesecloth or straining bag directly into the clean pot. Squeeze out as much liquid as possible (this is your soy milk!) from the cheesecloth or straining bag.
- Place the pot with the strained soymilk over medium heat. Cook for 20 minutes, stirring occasionally.
- Enjoy warm, or cool completely and refrigerate. The soy milk will last for 5 days in the refrigerator.
*Note: If you like your soy milk lighter (i.e., thinner in consistency), add the larger amount (6 cups) of water.