The composition of goat milk does not differ greatly from that of cow milk. Both kinds of milk contain about 13% dry solids.

Lactose is the most important carbohydrate present in milk. Lactose is a disaccharide comprised of glucose and galactose.

The lactose content of goat milk is about 10% lower than that of cow milk. The chemical structure of lactose in goat milk is identical to that of lactose in cow milk.

The other main ingredients of goat milk are milk fat, protein, and minerals. One hundred ml of milk has a calorific value of about 280 kJ (67 kcal).

The composition of the milk depends largely on the breed of goat. The composition of the milk also depends on the season.  In the summer the yield of milk is high, and The fat and protein contents are low. Conversely, in the winter the yield of milk is low, and the fat and protein contents are higher.

The differences in the composition of goat milk and cow milk also results in differences in their physical properties. For example, goats' milk has a lower heat stability than cows' milk, whilst the buffering capacity of goats' milk is greater than that of cows' milk.

Moreover, goat milk has an extremely white colour, which is due to the absence of carotene in the fat. Moreover the fat globules in goat milk are of a very small diameter; this results in a greater dispersion of light, thereby imparting the milk with its extremely white appearance.