Whether they pour it on cereal in the morning or drink it with an afternoon snack, Americans love milk. In fact, the United States produced more milk in 2021 than any other country.
But have you ever wondered why we drink milk from cows instead of milk from goats, deer, bison, whales or other milk-making mammals?
Well, the first part of the answer is simple.
“Cows are docile,” says Deborah Valenze, professor of history at Barnard College and author of the book “Milk: A Local and Global History.” Docile means that they don’t usually resist when you try to milk them. But most animals aren’t so relaxed. “If you’ve ever been around a goat, you know that they are very jumpy,” Valenze says. “They don’t really like being handled.”
The same goes for reindeer, which are milked by herders in places such as Scandinavia and Mongolia. “Reindeer have to be held by ropes, and sometimes it takes as many as two to three people to hold down a reindeer while it’s being milked,” says Valenze.
But ease is just one factor. Quantity is another. Even if you go to the trouble of milking a reindeer, the large animals can produce only a cup or two of milk each day. Cows — especially those that have been bred for milking — produce more than seven gallons of milk every 24 hours. So while reindeer milk or goat milk might make sense for a herder providing only for their family, it’s much easier to make a living with the amount of milk produced by cows.
Finally, there’s the matter of taste. “Goat and sheep milk has a sharp odor,” Valenze says. “And I’ve never tasted reindeer milk, but I’ve heard that reindeer cheese is tasteless.”
Cow milk is in between. It’s flavorful enough to add something when we cook with it, but not overpowering. At least to the human nose, cow’s milk is in the Goldilocks zone of being “just right.”
Of course, if you go to the grocery store, you’ll see that there are plenty of “milks” available that don’t come from an animal. There’s almond milk, soy milk and oat milk, to name just a few varieties. And the availability of these new, vegan options has started to cut into the amount of milk Americans drink each year — though slightly.
By the way, just because cow’s milk is very popular now doesn’t mean it will always be that way. Some businesses are trying to get Americans interested in camel’s milk, which has been popular with Bedouin tribes in the Middle East for thousands of years. Camel’s milk is slightly sweeter and saltier than the white stuff you’re used to. Any volunteers?
Bittel is a freelance journalist who often writes about animals. He is also the author of “How to Talk to a Tiger . . . and Other Animals.”
Jason Bittel writes about science for kids and adults. From the cute and cuddly to the hairy, scary and extraordinary, Bittel tries to teach people about the life all around us. He is also a former National Geographic Explorer and Knight Science Journalism Project Fellow.