Effect of Temperature on Milk Viscosity

With an increase in the temperature of milk, its viscosity will:

Correct Answer: Decrease

With an increase in temperature, the viscosity of milk decreases. This is consistent with the general behaviour of liquids — as temperature rises, molecular movement increases and intermolecular friction decreases, leading to reduced viscosity.

Viscosity of Milk — Key Values

• Viscosity of whole milk at 25°C: approximately 2.0 centipoise
• Viscosity of skim milk at 25°C: approximately 1.5 centipoise

Factors Affecting Milk Viscosity

• Temperature ↑ → Viscosity ↓ (inverse relationship)
• Homogenization → Viscosity ↑ (fat globule surface area increases, more friction)
• Fat content ↑ → Viscosity ↑
• Casein protein is primarily responsible for the viscosity and white colour of milk.

Remember the Contrast

• Temperature increase → viscosity decreases
• Homogenization → viscosity increases