Caseins play a central role in the dairy sector, as it is their controlled coagulation that allows the conversion of milk into cheese, yoghurt and caseinates, but also the creation of high-quality co-products from whey. Understanding caseins, their association into casein micelles and the properties of casein micelles is thus very important. Providing a complete and holistic understanding requires integration of findings from many fields of study, including organic and inorganic chemistry, biochemistry and physics, biology, lactational physiology, and food science. Combining such insights has gained insights over the past decades how 4 gene products and their genetic variants and post-translational modification can lead to casein associates which further grow to sterically-stabilized casein micelles through combination with calcium phosphate. No two cows produce the exact same casein micelles, and such differences can be explored and utilized, to provide both further insights into casein micelle properties and for industrial utilization.