Full disclosure: I am a dairy farmer’s granddaughter. Most of our neighbors when I was growing up had dairy farms. As an animal science major, I worked on dairy research and had to collect milk samples at the Cornell Teaching and Research Center at 4 in the morning for two weeks for one experiment.

Now that I’ve gotten the disclaimer out of the way, a current controversy is the labeling of alternate milks (soy, nut, rice, hemp) as milk. The dairy industry is lobbying to reserve the term milk to only those beverages made from lactating mammals. Obviously a LOT of money is involved here. Dairy farmers are getting record-low prices for milk. Some farmers are selling out or committing suicide because of the depressed prices for their products. Economics aside, how do milks from animal and plant sources compare nutrition- and cooking-wise?

This article on cnn,com offers a good overview of the nutritional differences between animal and plant milks. I’m going to concentrate on the cooking qualities. Chemistry is destiny in the kitchen, so substituting any plant-based milk for a large quantity of cow’s milk (more than a tablespoon or two) will give you different results. This is particularly true in items where the milk protein is essential to thickening. Let’s take the example of an egg custard. The protein in both cow’s milk and egg will denature (change structure) to thicken the custard. Let’s say you decide to substitute an equal amount of nut or coconut milk for the cow’s milk in the recipe. Because of the lower amount of protein in these alternatives, you may need to use more egg to achieve an equivalent amount of thickening. Coconut milk, even the “light” product, is higher in fat than cow’s milk, so the end result will have a much different texture and mouthfeel. Soy milk is close in protein content to cow’s milk, but the proteins may denature at a different temperature or interact differently with the egg protein. This article is a decent reference for substituting plant for animal milk.

The admonitions on using plant milks for cooking and baking goes double for cheese and yogurt substitutes. Additional fat or thickeners may be required to achieve anything close to comparable to dairy products. Some vegan products may come close to their dairy counterparts; others are sadly deficient.

For those who choose to be vegan or who have cow’s milk allergies or intolerances, plant milks can be viable alternatives. Just don’t expect them to duplicate dairy in the kitchen.