Why Is Milk White?

Jun 22, 2018

But Why heads to the farm to answer a whole herd of animal questions: How do cows make milk? Why do cows moo? Why do some animals eat grass? Why do pigs have curly tails? Why do pigs have more teats than cows? Why do eggs in the fridge not hatch? How do chicks grow in their eggs? Why do roosters crow? Why do horses have hooves? Why do horses stand up when they sleep? Why are some fences electric?
We get answers at Billings Farm and Museum in Woodstock, Vermont.


"Why is milk white?" - Vedant, 6, Santa Clara, Ca. and Violet, 5, Boston, Mass.

"Milk looks white to us because of the fat in the milk and also because of the protein called casein that's in the milk. It kind of reflects the wavelengths that make it look white to us," explains Christine Scales of Billings Farm. "If you've ever seen skim milk next to a whole fat milk, it might actually look a little bit more bluish because it doesn't have the fats in it to make it look white."

It takes a whole lot of eating and a whole lot of water to make that milk. Milk is 86% water and cows drink a bathtub full of water every day!

Why do cows make milk? Cows, like humans are mammals, and they make milk to feed their baby calves. Humans figured out that they could drink the milk as a source of nutrition and so they started raising and breeding cows for their milk and meat.

Listen to the full episode for answers to all of your farm questions.