Why is milk white?

Milk is naturally white, thanks to the interaction between water, fat and proteins that mix together to form tiny particles which reflect light.

Last updated 04/04/2024

Milk is a natural, whole food and a nutrient powerhouse made up of water, protein, fat, carbohydrates (in the form of lactose) vitamins including calcium, minerals including phosphorous and a range of other bioactive compounds.

Caseins are one of the main types of protein in milk which cluster together with calcium and phosphate to form tiny particles called micelles. When light hits these casein micelles it causes the light to refract and scatter in a certain way, giving milk its signature white hue.[1]

Back in the day, when milk came in bottles with aluminium caps, the cream would rise to the top, giving milk a paler look. But today, thanks to homogenization, milk undergoes a gentle pressurized journey through fine nozzles. This evens out the distribution of fat and protein, resulting in a velvety texture, a creamy taste, and a brighter, whiter appearance.

The Australian Food Standards Code allows for adjustments in milk components like lactose, protein, fat, and vitamins to ensure a consistent product. This means that previous natural variations in milk due to cow breeds or pasture differences are now smoothed out, giving us that beautiful, consistent, bright-white milk we know and love in Australia. No artificial colours are added to make milk white – it's all natural goodness.[2]

[1] Compound Chemistry. Why is milk white? Accessed 15.07.19 

[2] Food Standards Australia New Zealand. Food Standards Code. Accessed 15.07.19

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