Cow's Milk or Soy Milk - Which is Greener?

While soy milk is determinedly the more eco-conscious choice, it is not easy to compare it with cow's milk, despite common marketing as a dairy substitute. The two products are very different substances and also require very diverse production processes, which entail a broad range of environmental factors. Soy milk, although it has a similar consistency to milk, is composed of ground soy beans that have been separated from their characteristic fiber, along with water, vitamins, minerals and sugar. Though cow's milk has to be pasteurized and packaged, what you buy in the store is much closer to what comes off the farm.

Farming cow's milk bears the heavy burden of raising cows, which is known to be environmentally pricey, as they are major emitters of methane, produce large amounts of waste and require an enormous amount of energy to house and feed. Dairy production is not as clean as growing soy bean crops. In terms of energy used, in the best case scenario, it takes 10 calories of fossil fuel energy to produce one calorie of milk protein, while it takes a mere .75 calories to farm the same amount needed for one calorie of soy protein. Thus soy protein is roughly 13 times more energy efficient than dairy protein, even on the most energy efficient farm.

Though, still to be considered is the fact that soy beans are not the only factor in soy milk production. Not only do the other ingredients in soy milk need to be shipped from elsewhere; the process of adding them requires energy and produces a significant amount of waste. Also - the majority of soybeans are genetically modified. Additionally, because soy milk drinkers are, on the whole, an eco-conscious bunch, the products they buy tend to be made in a more sustainable way. For example, Silk, the largest producer of soy milk withclose to a 60% market share boasts an almost entirely organic product line.