How tofu and soy milk work
By Marshall Brain
http://www.JewishWorldReview.com | (MCT) I made it through three decades of my life without ever hearing about soy milk. Even though soy milk has been around for more than 2,000 years, I had no inkling that it existed. And then, suddenly, the refrigerator was filled with soy milk. In fact, we started making soy milk ourselves at home.
Which prompts the obvious question: What is soy milk? To make soy milk, you start with dried soybeans. If you have never seen a soybean before, think of a dried black-eyed pea without the black eye. If you wanted to, you could grow soybeans in your backyard garden in the same way you grow green beans or peas, but most people buy the dried beans in bags at the store.
To make soy milk, you start with half a cup of soybeans and soak them in water for half a day to soften them. You grind up the beans in a blender and boil the bean pulp in a quart of water. Then you filter the pulp out with a cloth and save the liquid. Voila - one quart of soy milk. It's a little like making coffee if you think about it. If you use a soy-milk maker, it will do the grinding, boiling and filtering for you, but it is exactly the same process.
What you have made is a liquid that is a lot like cow milk. One cup of "2 percent" cow milk contains about 5 grams of fat (in the form of cream) per cup. Soy milk also contains about 5 grams of fat (in the form of soybean oil) per cup. Cow milk contains about 8 grams of dairy protein. Soy milk contains about 7 grams of vegetable protein. Cow milk contains about 12 grams of sugar (in the form of lactose). Soy milk contains about 5 grams of carbohydrates, and many people add sugar. In other words, cow milk and soy milk are quite similar. But if you are making soy milk yourself it is very inexpensive compared to cow milk - about $1 a gallon. If you buy the beans in bulk, you can push the cost even lower.
Most people in America don't like the taste of pure soy milk, so they usually add salt and/or sugar to it. You could add, for example, half a teaspoon of salt and a tablespoon or two of maple syrup to a quart of soy milk and it would taste a lot more like cow milk.
What about tofu? Tofu and cheese are nearly identical. To make cheese, you start with cow milk, coagulate it and press the curds. To make Tofu, you start with soy milk, coagulate it and press the curds. To coagulate soy milk you use calcium sulfate, and the whole process of making tofu is pretty simple. You boil the soy milk and add calcium sulfate. Once the soy milk coagulates, you strain out the curds and wrap them in a cloth. Then you press the curds with three to five pounds of weight for 20 minutes. You normally press the curds in a small wooden or metal box that gives the tofu is traditional blocky shape.
If you were to start with soaked soy beans, make the soy milk and then make tofu, the whole process would take less than 2 hours.
There are several advantages to tofu when you compare it to cheese or meat. The biggest difference is fat and calories. Four ounces of cheddar cheese contains 40 grams of fat (most of it saturated animal fat) and 480 calories. Four ounces of firm tofu contains 5 grams of fat and only 80 calories. The cheese holds 24 grams of protein, while the tofu has 10 grams. The other thing that tofu contains is isoflavones, which are thought to have a number of health benefits. In addition, the soy in tofu has shown some ability to lower "bad" cholesterol.
When made from scratch, tofu is very inexpensive - about $1 a pound. As a source of high-quality, low-fat protein, that price is hard to beat.
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